1
Data Communication amp Networking DKT 224
Mohd Fairuz Bin Muhd Fadzil04-9855153 019-4141205
Tingkat 1KKF1aTaman Kuala Perlis
School of Computer amp Communication Engineering
mohdfairuzunimapedumy
2
Course Outcomes1 Students will be able to understand the theory
and basic of data communication and network2 Able to identify network connection concept and
protocol used3 Students will be familiarized with the data
communication network equipments and instruments to analyze network protocol and perform some troubleshooting
4 Students be exposed to network architecture and new technologies in data communication and network
3
Assessment
Final Exam - 50 Course Work ndash 50
Lab Reportstest ndash 30 Test 1 amp 2 ndash 15 AssignmentQuiz ndash 4 Attendance tutorials ndash 1
4
Lab experiment LAB 1 - Fundamental of Data
Communication Technique LAB 2 - Network protocol analyzer LAB 3 - Network setup Client-Server LAB 4 - Wireless access point configuration LAB 5 - Network Analysis ndashmeasuring Throughput
5
References
1Behrouz A Forouzan Data Communications and
Networking 4th Edition McGraw Hill 2007 (TEXT BOOK)
2 William Stalling Data and Computer
Communications 7th Edition Prentice Hall 2005
3Wayne Tomasi Introduction to Data
Communications and Networking
Prentice Hall2004
6
Chapter 1
Introduction
Copyright copy The McGraw-Hill Companies Inc Permission required for reproduction or display
7
1-1 DATA COMMUNICATIONS1-1 DATA COMMUNICATIONS
The term The term telecommunicationtelecommunication means communication at a means communication at a distance The word distance The word datadata refers to information presented in refers to information presented in whatever form is agreed upon by the parties creating and whatever form is agreed upon by the parties creating and using the data using the data Data communicationsData communications are the exchange of are the exchange of data between two devices via some form of transmission data between two devices via some form of transmission medium such as a wire cable medium such as a wire cable
ComponentsData RepresentationData Flow
Topics discussed in this sectionTopics discussed in this section
8
Figure 11 Five components of data communication
9
Data Representation
bull TEXT ndash unicode (32 bits to represent character)- ASCII
bull NUMBERS
bull IMAGES-composed of a matrix of pixel
bull AUDIO- recording or broadcasting of sound or music
bull VIDEO- recording or broadcasting of a
bull picture or movie
10
Figure 12 Data flow (simplex half-duplex and full-duplex)
11
1-2 NETWORKS1-2 NETWORKS
A A networknetwork is a set of devices (often referred to as is a set of devices (often referred to as nodesnodes) ) connected by communication connected by communication linkslinks A node can be a A node can be a computer printer or any other device capable of sending computer printer or any other device capable of sending andor receiving data generated by other nodes on the andor receiving data generated by other nodes on the networknetwork
Distributed ProcessingNetwork CriteriaPhysical StructuresNetwork ModelsCategories of NetworksInterconnection of Networks Internetwork
Topics discussed in this sectionTopics discussed in this section
12
NETWORKS
Set of nodes connected via physical links ndash 1) Distributing Processing ndash 2) Sharing Data and centralization ndash 3) Security and robustness
13
Network Criteria
bull
1) Performance Transmission and response times - throughput and delay 2) Reliability How often the networks fail 3) Security Privacy and integrity of
communication Data recovery from breaches and data loss
14
Physical Structures
bull Types of connections
bull 1) Point to Point (P to P) Dedicated link to be utilized only by end devices
bull 2) Multipoint (Multidrop) Many end devices share the link capacity
15
Figure 13 Types of connections point-to-point and multipoint
16
Physical Topology
17
Figure 14 Categories of topology
18
Physical Topology
bull A) Mesh
bull Each device has dedicated point-to-point link to other devices Fully connected mesh will have n( n-1) 2 FD links ndash Where n = number of nodes
bull Advantages Fast communication Robust and Privacy (Security)
bull Disadvantages Cabling Space and cost
19
Figure 15 A fully connected mesh topology (five devices)
20
Physical Topology (cont)
bull B) Star
bull Devices are connected Point to Point to a central ldquoHubrdquo (Controller Exchanger)
bull Advantages Less cabling and HW ports two hops only
bull Disadvantage Not robust
21
Figure 16 A star topology connecting four stations
22
Figure 17 A bus topology connecting three stations
23
ndash C) Bus
bull Multipoint link as ldquobackbonerdquo for a network where devices have drop line to tap into the bus
Advantage Less Cabling bull Disadvantages Topology dependent limit
number of nodes on the bus due to signal power loss with distance not so robust
24
Figure 18 A ring topology connecting six stations
25
bull C) Ring Each device connects Point to Point with only two other devices in a left and right neighbors arrangement via a repeater
bull Advantages easy installation better fault isolation and robustness
bull Disadvantages N2 hops communication
26
Figure 19 A hybrid topology a star backbone with three bus networks
27
bull D) Hybrid bull Pizza ldquostarrdquo inside a ldquo ringrdquo
bull Pros Better robustness still low cost Delay is 1 hop (until the star is not with a ring cut max 2 bull Star of busses
28
Categories of Networks
bull Local Area Networks (LAN) Few Kilometers Connects devices (PCs printers servers) within the same room building company and campus
bull Topologies most used are bus ring and star
29
Figure 110 An isolated LAN connecting 12 computers to a hub in a closet
30
Categories of Networks(cont)
bull Wide Area Networks (WAN)
bull span a large geographical area about 100rsquos ndash 1000rsquos of Km
bull 1) Switched End users connected via a cloud of switches (subnet)
bull 2) Point-to Point Line leased from telephone company TV connecting users
to the ISP for Internet access
31
bull alternative technologies used includendash circuit switchingndash packet switchingndash frame relayndash Asynchronous Transfer Mode (ATM)
32
Circuit Switching
bull uses a dedicated communications path established for duration of conversation
bull comprising a sequence of physical links
bull with a dedicated logical channel
bull eg telephone network
33
Packet Switching
bull data sent out of sequence
bull small chunks (packets) of data at a time
bull packets passed from node to node between source and destination
bull used for terminal to computer and computer to computer communications
34
Frame Relay
bull packet switching systems have large overheads to compensate for errors
bull modern systems are more reliable
bull errors can be caught in end system
bull Frame Relay provides higher speeds
bull with most error control overhead removed
35
Asynchronous Transfer Mode(ATM)
bull evolution of frame relay
bull fixed packet (called cell) length
bull with little overhead for error control
bull anything from 10Mbps to Gbps
bull constant data rate using packet switching technique with multiple virtual circuits
36
Figure 111 WANs a switched WAN and a point-to-point WAN
37
Figure 112 A heterogeneous network made of four WANs and two LANs
38
Categories of Networks(cont)
bull Metropolitan Area Networks
bull MAN towncity
bull High-speed backbone linking multiple LANrsquos DSL TV cables
39
1-3 THE INTERNET1-3 THE INTERNET
The The InternetInternet has revolutionized many aspects of our has revolutionized many aspects of our daily lives It has affected the way we do business as well as the daily lives It has affected the way we do business as well as the way we spend our leisure time The Internet is a way we spend our leisure time The Internet is a communication system that has brought a wealth of communication system that has brought a wealth of information to our fingertips and organized it for our use information to our fingertips and organized it for our use
A Brief History The Internet Today (ISPs)
Topics discussed in this sectionTopics discussed in this section
40
The Internet
bull Internet evolved from ARPANETndash first operational packet networkndash applied to tactical radio amp satellite nets alsondash had a need for interoperabilityndash lead to standardized TCPIP protocols
41
The Internet
bull Huge number of interconnected Networks (100000rsquos) private organized egrsquo government schools research facilities in many countries
bull Collection of LANrsquoS MANrsquoS and WANrsquos ndash 1048708 The internet protocol stack is the TCPIP ndash 1048708 End users use the internet via Internet Service providers
(ISPs) which are of the following hierarchies
42
Figure 113 Hierarchical organization of the Internet
43
Internet Elements
44
Internet Architecture
45
Example Configuration
46
1-4 PROTOCOLS AND STANDARDS1-4 PROTOCOLS AND STANDARDS
In this section we define two widely used terms In this section we define two widely used terms protocolsprotocols and and standardsstandards First we define protocol which is synonymous with First we define protocol which is synonymous with rule Then we discuss standards which are agreed-upon rulesrule Then we discuss standards which are agreed-upon rules
ProtocolsStandardsStandards OrganizationsInternet Standards
Topics discussed in this sectionTopics discussed in this section
47
What is a protocol
Communications between computers requires very specific unambiguous rules A protocol is a set of rules that governs how two or more communicating parties are to interactExamples
Internet Protocol (IP)Transmission Control Protocol (TCP)HyperText Transfer Protocol (HTTP)Simple Mail Transfer Protocol (SMTP)
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
2
Course Outcomes1 Students will be able to understand the theory
and basic of data communication and network2 Able to identify network connection concept and
protocol used3 Students will be familiarized with the data
communication network equipments and instruments to analyze network protocol and perform some troubleshooting
4 Students be exposed to network architecture and new technologies in data communication and network
3
Assessment
Final Exam - 50 Course Work ndash 50
Lab Reportstest ndash 30 Test 1 amp 2 ndash 15 AssignmentQuiz ndash 4 Attendance tutorials ndash 1
4
Lab experiment LAB 1 - Fundamental of Data
Communication Technique LAB 2 - Network protocol analyzer LAB 3 - Network setup Client-Server LAB 4 - Wireless access point configuration LAB 5 - Network Analysis ndashmeasuring Throughput
5
References
1Behrouz A Forouzan Data Communications and
Networking 4th Edition McGraw Hill 2007 (TEXT BOOK)
2 William Stalling Data and Computer
Communications 7th Edition Prentice Hall 2005
3Wayne Tomasi Introduction to Data
Communications and Networking
Prentice Hall2004
6
Chapter 1
Introduction
Copyright copy The McGraw-Hill Companies Inc Permission required for reproduction or display
7
1-1 DATA COMMUNICATIONS1-1 DATA COMMUNICATIONS
The term The term telecommunicationtelecommunication means communication at a means communication at a distance The word distance The word datadata refers to information presented in refers to information presented in whatever form is agreed upon by the parties creating and whatever form is agreed upon by the parties creating and using the data using the data Data communicationsData communications are the exchange of are the exchange of data between two devices via some form of transmission data between two devices via some form of transmission medium such as a wire cable medium such as a wire cable
ComponentsData RepresentationData Flow
Topics discussed in this sectionTopics discussed in this section
8
Figure 11 Five components of data communication
9
Data Representation
bull TEXT ndash unicode (32 bits to represent character)- ASCII
bull NUMBERS
bull IMAGES-composed of a matrix of pixel
bull AUDIO- recording or broadcasting of sound or music
bull VIDEO- recording or broadcasting of a
bull picture or movie
10
Figure 12 Data flow (simplex half-duplex and full-duplex)
11
1-2 NETWORKS1-2 NETWORKS
A A networknetwork is a set of devices (often referred to as is a set of devices (often referred to as nodesnodes) ) connected by communication connected by communication linkslinks A node can be a A node can be a computer printer or any other device capable of sending computer printer or any other device capable of sending andor receiving data generated by other nodes on the andor receiving data generated by other nodes on the networknetwork
Distributed ProcessingNetwork CriteriaPhysical StructuresNetwork ModelsCategories of NetworksInterconnection of Networks Internetwork
Topics discussed in this sectionTopics discussed in this section
12
NETWORKS
Set of nodes connected via physical links ndash 1) Distributing Processing ndash 2) Sharing Data and centralization ndash 3) Security and robustness
13
Network Criteria
bull
1) Performance Transmission and response times - throughput and delay 2) Reliability How often the networks fail 3) Security Privacy and integrity of
communication Data recovery from breaches and data loss
14
Physical Structures
bull Types of connections
bull 1) Point to Point (P to P) Dedicated link to be utilized only by end devices
bull 2) Multipoint (Multidrop) Many end devices share the link capacity
15
Figure 13 Types of connections point-to-point and multipoint
16
Physical Topology
17
Figure 14 Categories of topology
18
Physical Topology
bull A) Mesh
bull Each device has dedicated point-to-point link to other devices Fully connected mesh will have n( n-1) 2 FD links ndash Where n = number of nodes
bull Advantages Fast communication Robust and Privacy (Security)
bull Disadvantages Cabling Space and cost
19
Figure 15 A fully connected mesh topology (five devices)
20
Physical Topology (cont)
bull B) Star
bull Devices are connected Point to Point to a central ldquoHubrdquo (Controller Exchanger)
bull Advantages Less cabling and HW ports two hops only
bull Disadvantage Not robust
21
Figure 16 A star topology connecting four stations
22
Figure 17 A bus topology connecting three stations
23
ndash C) Bus
bull Multipoint link as ldquobackbonerdquo for a network where devices have drop line to tap into the bus
Advantage Less Cabling bull Disadvantages Topology dependent limit
number of nodes on the bus due to signal power loss with distance not so robust
24
Figure 18 A ring topology connecting six stations
25
bull C) Ring Each device connects Point to Point with only two other devices in a left and right neighbors arrangement via a repeater
bull Advantages easy installation better fault isolation and robustness
bull Disadvantages N2 hops communication
26
Figure 19 A hybrid topology a star backbone with three bus networks
27
bull D) Hybrid bull Pizza ldquostarrdquo inside a ldquo ringrdquo
bull Pros Better robustness still low cost Delay is 1 hop (until the star is not with a ring cut max 2 bull Star of busses
28
Categories of Networks
bull Local Area Networks (LAN) Few Kilometers Connects devices (PCs printers servers) within the same room building company and campus
bull Topologies most used are bus ring and star
29
Figure 110 An isolated LAN connecting 12 computers to a hub in a closet
30
Categories of Networks(cont)
bull Wide Area Networks (WAN)
bull span a large geographical area about 100rsquos ndash 1000rsquos of Km
bull 1) Switched End users connected via a cloud of switches (subnet)
bull 2) Point-to Point Line leased from telephone company TV connecting users
to the ISP for Internet access
31
bull alternative technologies used includendash circuit switchingndash packet switchingndash frame relayndash Asynchronous Transfer Mode (ATM)
32
Circuit Switching
bull uses a dedicated communications path established for duration of conversation
bull comprising a sequence of physical links
bull with a dedicated logical channel
bull eg telephone network
33
Packet Switching
bull data sent out of sequence
bull small chunks (packets) of data at a time
bull packets passed from node to node between source and destination
bull used for terminal to computer and computer to computer communications
34
Frame Relay
bull packet switching systems have large overheads to compensate for errors
bull modern systems are more reliable
bull errors can be caught in end system
bull Frame Relay provides higher speeds
bull with most error control overhead removed
35
Asynchronous Transfer Mode(ATM)
bull evolution of frame relay
bull fixed packet (called cell) length
bull with little overhead for error control
bull anything from 10Mbps to Gbps
bull constant data rate using packet switching technique with multiple virtual circuits
36
Figure 111 WANs a switched WAN and a point-to-point WAN
37
Figure 112 A heterogeneous network made of four WANs and two LANs
38
Categories of Networks(cont)
bull Metropolitan Area Networks
bull MAN towncity
bull High-speed backbone linking multiple LANrsquos DSL TV cables
39
1-3 THE INTERNET1-3 THE INTERNET
The The InternetInternet has revolutionized many aspects of our has revolutionized many aspects of our daily lives It has affected the way we do business as well as the daily lives It has affected the way we do business as well as the way we spend our leisure time The Internet is a way we spend our leisure time The Internet is a communication system that has brought a wealth of communication system that has brought a wealth of information to our fingertips and organized it for our use information to our fingertips and organized it for our use
A Brief History The Internet Today (ISPs)
Topics discussed in this sectionTopics discussed in this section
40
The Internet
bull Internet evolved from ARPANETndash first operational packet networkndash applied to tactical radio amp satellite nets alsondash had a need for interoperabilityndash lead to standardized TCPIP protocols
41
The Internet
bull Huge number of interconnected Networks (100000rsquos) private organized egrsquo government schools research facilities in many countries
bull Collection of LANrsquoS MANrsquoS and WANrsquos ndash 1048708 The internet protocol stack is the TCPIP ndash 1048708 End users use the internet via Internet Service providers
(ISPs) which are of the following hierarchies
42
Figure 113 Hierarchical organization of the Internet
43
Internet Elements
44
Internet Architecture
45
Example Configuration
46
1-4 PROTOCOLS AND STANDARDS1-4 PROTOCOLS AND STANDARDS
In this section we define two widely used terms In this section we define two widely used terms protocolsprotocols and and standardsstandards First we define protocol which is synonymous with First we define protocol which is synonymous with rule Then we discuss standards which are agreed-upon rulesrule Then we discuss standards which are agreed-upon rules
ProtocolsStandardsStandards OrganizationsInternet Standards
Topics discussed in this sectionTopics discussed in this section
47
What is a protocol
Communications between computers requires very specific unambiguous rules A protocol is a set of rules that governs how two or more communicating parties are to interactExamples
Internet Protocol (IP)Transmission Control Protocol (TCP)HyperText Transfer Protocol (HTTP)Simple Mail Transfer Protocol (SMTP)
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
3
Assessment
Final Exam - 50 Course Work ndash 50
Lab Reportstest ndash 30 Test 1 amp 2 ndash 15 AssignmentQuiz ndash 4 Attendance tutorials ndash 1
4
Lab experiment LAB 1 - Fundamental of Data
Communication Technique LAB 2 - Network protocol analyzer LAB 3 - Network setup Client-Server LAB 4 - Wireless access point configuration LAB 5 - Network Analysis ndashmeasuring Throughput
5
References
1Behrouz A Forouzan Data Communications and
Networking 4th Edition McGraw Hill 2007 (TEXT BOOK)
2 William Stalling Data and Computer
Communications 7th Edition Prentice Hall 2005
3Wayne Tomasi Introduction to Data
Communications and Networking
Prentice Hall2004
6
Chapter 1
Introduction
Copyright copy The McGraw-Hill Companies Inc Permission required for reproduction or display
7
1-1 DATA COMMUNICATIONS1-1 DATA COMMUNICATIONS
The term The term telecommunicationtelecommunication means communication at a means communication at a distance The word distance The word datadata refers to information presented in refers to information presented in whatever form is agreed upon by the parties creating and whatever form is agreed upon by the parties creating and using the data using the data Data communicationsData communications are the exchange of are the exchange of data between two devices via some form of transmission data between two devices via some form of transmission medium such as a wire cable medium such as a wire cable
ComponentsData RepresentationData Flow
Topics discussed in this sectionTopics discussed in this section
8
Figure 11 Five components of data communication
9
Data Representation
bull TEXT ndash unicode (32 bits to represent character)- ASCII
bull NUMBERS
bull IMAGES-composed of a matrix of pixel
bull AUDIO- recording or broadcasting of sound or music
bull VIDEO- recording or broadcasting of a
bull picture or movie
10
Figure 12 Data flow (simplex half-duplex and full-duplex)
11
1-2 NETWORKS1-2 NETWORKS
A A networknetwork is a set of devices (often referred to as is a set of devices (often referred to as nodesnodes) ) connected by communication connected by communication linkslinks A node can be a A node can be a computer printer or any other device capable of sending computer printer or any other device capable of sending andor receiving data generated by other nodes on the andor receiving data generated by other nodes on the networknetwork
Distributed ProcessingNetwork CriteriaPhysical StructuresNetwork ModelsCategories of NetworksInterconnection of Networks Internetwork
Topics discussed in this sectionTopics discussed in this section
12
NETWORKS
Set of nodes connected via physical links ndash 1) Distributing Processing ndash 2) Sharing Data and centralization ndash 3) Security and robustness
13
Network Criteria
bull
1) Performance Transmission and response times - throughput and delay 2) Reliability How often the networks fail 3) Security Privacy and integrity of
communication Data recovery from breaches and data loss
14
Physical Structures
bull Types of connections
bull 1) Point to Point (P to P) Dedicated link to be utilized only by end devices
bull 2) Multipoint (Multidrop) Many end devices share the link capacity
15
Figure 13 Types of connections point-to-point and multipoint
16
Physical Topology
17
Figure 14 Categories of topology
18
Physical Topology
bull A) Mesh
bull Each device has dedicated point-to-point link to other devices Fully connected mesh will have n( n-1) 2 FD links ndash Where n = number of nodes
bull Advantages Fast communication Robust and Privacy (Security)
bull Disadvantages Cabling Space and cost
19
Figure 15 A fully connected mesh topology (five devices)
20
Physical Topology (cont)
bull B) Star
bull Devices are connected Point to Point to a central ldquoHubrdquo (Controller Exchanger)
bull Advantages Less cabling and HW ports two hops only
bull Disadvantage Not robust
21
Figure 16 A star topology connecting four stations
22
Figure 17 A bus topology connecting three stations
23
ndash C) Bus
bull Multipoint link as ldquobackbonerdquo for a network where devices have drop line to tap into the bus
Advantage Less Cabling bull Disadvantages Topology dependent limit
number of nodes on the bus due to signal power loss with distance not so robust
24
Figure 18 A ring topology connecting six stations
25
bull C) Ring Each device connects Point to Point with only two other devices in a left and right neighbors arrangement via a repeater
bull Advantages easy installation better fault isolation and robustness
bull Disadvantages N2 hops communication
26
Figure 19 A hybrid topology a star backbone with three bus networks
27
bull D) Hybrid bull Pizza ldquostarrdquo inside a ldquo ringrdquo
bull Pros Better robustness still low cost Delay is 1 hop (until the star is not with a ring cut max 2 bull Star of busses
28
Categories of Networks
bull Local Area Networks (LAN) Few Kilometers Connects devices (PCs printers servers) within the same room building company and campus
bull Topologies most used are bus ring and star
29
Figure 110 An isolated LAN connecting 12 computers to a hub in a closet
30
Categories of Networks(cont)
bull Wide Area Networks (WAN)
bull span a large geographical area about 100rsquos ndash 1000rsquos of Km
bull 1) Switched End users connected via a cloud of switches (subnet)
bull 2) Point-to Point Line leased from telephone company TV connecting users
to the ISP for Internet access
31
bull alternative technologies used includendash circuit switchingndash packet switchingndash frame relayndash Asynchronous Transfer Mode (ATM)
32
Circuit Switching
bull uses a dedicated communications path established for duration of conversation
bull comprising a sequence of physical links
bull with a dedicated logical channel
bull eg telephone network
33
Packet Switching
bull data sent out of sequence
bull small chunks (packets) of data at a time
bull packets passed from node to node between source and destination
bull used for terminal to computer and computer to computer communications
34
Frame Relay
bull packet switching systems have large overheads to compensate for errors
bull modern systems are more reliable
bull errors can be caught in end system
bull Frame Relay provides higher speeds
bull with most error control overhead removed
35
Asynchronous Transfer Mode(ATM)
bull evolution of frame relay
bull fixed packet (called cell) length
bull with little overhead for error control
bull anything from 10Mbps to Gbps
bull constant data rate using packet switching technique with multiple virtual circuits
36
Figure 111 WANs a switched WAN and a point-to-point WAN
37
Figure 112 A heterogeneous network made of four WANs and two LANs
38
Categories of Networks(cont)
bull Metropolitan Area Networks
bull MAN towncity
bull High-speed backbone linking multiple LANrsquos DSL TV cables
39
1-3 THE INTERNET1-3 THE INTERNET
The The InternetInternet has revolutionized many aspects of our has revolutionized many aspects of our daily lives It has affected the way we do business as well as the daily lives It has affected the way we do business as well as the way we spend our leisure time The Internet is a way we spend our leisure time The Internet is a communication system that has brought a wealth of communication system that has brought a wealth of information to our fingertips and organized it for our use information to our fingertips and organized it for our use
A Brief History The Internet Today (ISPs)
Topics discussed in this sectionTopics discussed in this section
40
The Internet
bull Internet evolved from ARPANETndash first operational packet networkndash applied to tactical radio amp satellite nets alsondash had a need for interoperabilityndash lead to standardized TCPIP protocols
41
The Internet
bull Huge number of interconnected Networks (100000rsquos) private organized egrsquo government schools research facilities in many countries
bull Collection of LANrsquoS MANrsquoS and WANrsquos ndash 1048708 The internet protocol stack is the TCPIP ndash 1048708 End users use the internet via Internet Service providers
(ISPs) which are of the following hierarchies
42
Figure 113 Hierarchical organization of the Internet
43
Internet Elements
44
Internet Architecture
45
Example Configuration
46
1-4 PROTOCOLS AND STANDARDS1-4 PROTOCOLS AND STANDARDS
In this section we define two widely used terms In this section we define two widely used terms protocolsprotocols and and standardsstandards First we define protocol which is synonymous with First we define protocol which is synonymous with rule Then we discuss standards which are agreed-upon rulesrule Then we discuss standards which are agreed-upon rules
ProtocolsStandardsStandards OrganizationsInternet Standards
Topics discussed in this sectionTopics discussed in this section
47
What is a protocol
Communications between computers requires very specific unambiguous rules A protocol is a set of rules that governs how two or more communicating parties are to interactExamples
Internet Protocol (IP)Transmission Control Protocol (TCP)HyperText Transfer Protocol (HTTP)Simple Mail Transfer Protocol (SMTP)
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
4
Lab experiment LAB 1 - Fundamental of Data
Communication Technique LAB 2 - Network protocol analyzer LAB 3 - Network setup Client-Server LAB 4 - Wireless access point configuration LAB 5 - Network Analysis ndashmeasuring Throughput
5
References
1Behrouz A Forouzan Data Communications and
Networking 4th Edition McGraw Hill 2007 (TEXT BOOK)
2 William Stalling Data and Computer
Communications 7th Edition Prentice Hall 2005
3Wayne Tomasi Introduction to Data
Communications and Networking
Prentice Hall2004
6
Chapter 1
Introduction
Copyright copy The McGraw-Hill Companies Inc Permission required for reproduction or display
7
1-1 DATA COMMUNICATIONS1-1 DATA COMMUNICATIONS
The term The term telecommunicationtelecommunication means communication at a means communication at a distance The word distance The word datadata refers to information presented in refers to information presented in whatever form is agreed upon by the parties creating and whatever form is agreed upon by the parties creating and using the data using the data Data communicationsData communications are the exchange of are the exchange of data between two devices via some form of transmission data between two devices via some form of transmission medium such as a wire cable medium such as a wire cable
ComponentsData RepresentationData Flow
Topics discussed in this sectionTopics discussed in this section
8
Figure 11 Five components of data communication
9
Data Representation
bull TEXT ndash unicode (32 bits to represent character)- ASCII
bull NUMBERS
bull IMAGES-composed of a matrix of pixel
bull AUDIO- recording or broadcasting of sound or music
bull VIDEO- recording or broadcasting of a
bull picture or movie
10
Figure 12 Data flow (simplex half-duplex and full-duplex)
11
1-2 NETWORKS1-2 NETWORKS
A A networknetwork is a set of devices (often referred to as is a set of devices (often referred to as nodesnodes) ) connected by communication connected by communication linkslinks A node can be a A node can be a computer printer or any other device capable of sending computer printer or any other device capable of sending andor receiving data generated by other nodes on the andor receiving data generated by other nodes on the networknetwork
Distributed ProcessingNetwork CriteriaPhysical StructuresNetwork ModelsCategories of NetworksInterconnection of Networks Internetwork
Topics discussed in this sectionTopics discussed in this section
12
NETWORKS
Set of nodes connected via physical links ndash 1) Distributing Processing ndash 2) Sharing Data and centralization ndash 3) Security and robustness
13
Network Criteria
bull
1) Performance Transmission and response times - throughput and delay 2) Reliability How often the networks fail 3) Security Privacy and integrity of
communication Data recovery from breaches and data loss
14
Physical Structures
bull Types of connections
bull 1) Point to Point (P to P) Dedicated link to be utilized only by end devices
bull 2) Multipoint (Multidrop) Many end devices share the link capacity
15
Figure 13 Types of connections point-to-point and multipoint
16
Physical Topology
17
Figure 14 Categories of topology
18
Physical Topology
bull A) Mesh
bull Each device has dedicated point-to-point link to other devices Fully connected mesh will have n( n-1) 2 FD links ndash Where n = number of nodes
bull Advantages Fast communication Robust and Privacy (Security)
bull Disadvantages Cabling Space and cost
19
Figure 15 A fully connected mesh topology (five devices)
20
Physical Topology (cont)
bull B) Star
bull Devices are connected Point to Point to a central ldquoHubrdquo (Controller Exchanger)
bull Advantages Less cabling and HW ports two hops only
bull Disadvantage Not robust
21
Figure 16 A star topology connecting four stations
22
Figure 17 A bus topology connecting three stations
23
ndash C) Bus
bull Multipoint link as ldquobackbonerdquo for a network where devices have drop line to tap into the bus
Advantage Less Cabling bull Disadvantages Topology dependent limit
number of nodes on the bus due to signal power loss with distance not so robust
24
Figure 18 A ring topology connecting six stations
25
bull C) Ring Each device connects Point to Point with only two other devices in a left and right neighbors arrangement via a repeater
bull Advantages easy installation better fault isolation and robustness
bull Disadvantages N2 hops communication
26
Figure 19 A hybrid topology a star backbone with three bus networks
27
bull D) Hybrid bull Pizza ldquostarrdquo inside a ldquo ringrdquo
bull Pros Better robustness still low cost Delay is 1 hop (until the star is not with a ring cut max 2 bull Star of busses
28
Categories of Networks
bull Local Area Networks (LAN) Few Kilometers Connects devices (PCs printers servers) within the same room building company and campus
bull Topologies most used are bus ring and star
29
Figure 110 An isolated LAN connecting 12 computers to a hub in a closet
30
Categories of Networks(cont)
bull Wide Area Networks (WAN)
bull span a large geographical area about 100rsquos ndash 1000rsquos of Km
bull 1) Switched End users connected via a cloud of switches (subnet)
bull 2) Point-to Point Line leased from telephone company TV connecting users
to the ISP for Internet access
31
bull alternative technologies used includendash circuit switchingndash packet switchingndash frame relayndash Asynchronous Transfer Mode (ATM)
32
Circuit Switching
bull uses a dedicated communications path established for duration of conversation
bull comprising a sequence of physical links
bull with a dedicated logical channel
bull eg telephone network
33
Packet Switching
bull data sent out of sequence
bull small chunks (packets) of data at a time
bull packets passed from node to node between source and destination
bull used for terminal to computer and computer to computer communications
34
Frame Relay
bull packet switching systems have large overheads to compensate for errors
bull modern systems are more reliable
bull errors can be caught in end system
bull Frame Relay provides higher speeds
bull with most error control overhead removed
35
Asynchronous Transfer Mode(ATM)
bull evolution of frame relay
bull fixed packet (called cell) length
bull with little overhead for error control
bull anything from 10Mbps to Gbps
bull constant data rate using packet switching technique with multiple virtual circuits
36
Figure 111 WANs a switched WAN and a point-to-point WAN
37
Figure 112 A heterogeneous network made of four WANs and two LANs
38
Categories of Networks(cont)
bull Metropolitan Area Networks
bull MAN towncity
bull High-speed backbone linking multiple LANrsquos DSL TV cables
39
1-3 THE INTERNET1-3 THE INTERNET
The The InternetInternet has revolutionized many aspects of our has revolutionized many aspects of our daily lives It has affected the way we do business as well as the daily lives It has affected the way we do business as well as the way we spend our leisure time The Internet is a way we spend our leisure time The Internet is a communication system that has brought a wealth of communication system that has brought a wealth of information to our fingertips and organized it for our use information to our fingertips and organized it for our use
A Brief History The Internet Today (ISPs)
Topics discussed in this sectionTopics discussed in this section
40
The Internet
bull Internet evolved from ARPANETndash first operational packet networkndash applied to tactical radio amp satellite nets alsondash had a need for interoperabilityndash lead to standardized TCPIP protocols
41
The Internet
bull Huge number of interconnected Networks (100000rsquos) private organized egrsquo government schools research facilities in many countries
bull Collection of LANrsquoS MANrsquoS and WANrsquos ndash 1048708 The internet protocol stack is the TCPIP ndash 1048708 End users use the internet via Internet Service providers
(ISPs) which are of the following hierarchies
42
Figure 113 Hierarchical organization of the Internet
43
Internet Elements
44
Internet Architecture
45
Example Configuration
46
1-4 PROTOCOLS AND STANDARDS1-4 PROTOCOLS AND STANDARDS
In this section we define two widely used terms In this section we define two widely used terms protocolsprotocols and and standardsstandards First we define protocol which is synonymous with First we define protocol which is synonymous with rule Then we discuss standards which are agreed-upon rulesrule Then we discuss standards which are agreed-upon rules
ProtocolsStandardsStandards OrganizationsInternet Standards
Topics discussed in this sectionTopics discussed in this section
47
What is a protocol
Communications between computers requires very specific unambiguous rules A protocol is a set of rules that governs how two or more communicating parties are to interactExamples
Internet Protocol (IP)Transmission Control Protocol (TCP)HyperText Transfer Protocol (HTTP)Simple Mail Transfer Protocol (SMTP)
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
5
References
1Behrouz A Forouzan Data Communications and
Networking 4th Edition McGraw Hill 2007 (TEXT BOOK)
2 William Stalling Data and Computer
Communications 7th Edition Prentice Hall 2005
3Wayne Tomasi Introduction to Data
Communications and Networking
Prentice Hall2004
6
Chapter 1
Introduction
Copyright copy The McGraw-Hill Companies Inc Permission required for reproduction or display
7
1-1 DATA COMMUNICATIONS1-1 DATA COMMUNICATIONS
The term The term telecommunicationtelecommunication means communication at a means communication at a distance The word distance The word datadata refers to information presented in refers to information presented in whatever form is agreed upon by the parties creating and whatever form is agreed upon by the parties creating and using the data using the data Data communicationsData communications are the exchange of are the exchange of data between two devices via some form of transmission data between two devices via some form of transmission medium such as a wire cable medium such as a wire cable
ComponentsData RepresentationData Flow
Topics discussed in this sectionTopics discussed in this section
8
Figure 11 Five components of data communication
9
Data Representation
bull TEXT ndash unicode (32 bits to represent character)- ASCII
bull NUMBERS
bull IMAGES-composed of a matrix of pixel
bull AUDIO- recording or broadcasting of sound or music
bull VIDEO- recording or broadcasting of a
bull picture or movie
10
Figure 12 Data flow (simplex half-duplex and full-duplex)
11
1-2 NETWORKS1-2 NETWORKS
A A networknetwork is a set of devices (often referred to as is a set of devices (often referred to as nodesnodes) ) connected by communication connected by communication linkslinks A node can be a A node can be a computer printer or any other device capable of sending computer printer or any other device capable of sending andor receiving data generated by other nodes on the andor receiving data generated by other nodes on the networknetwork
Distributed ProcessingNetwork CriteriaPhysical StructuresNetwork ModelsCategories of NetworksInterconnection of Networks Internetwork
Topics discussed in this sectionTopics discussed in this section
12
NETWORKS
Set of nodes connected via physical links ndash 1) Distributing Processing ndash 2) Sharing Data and centralization ndash 3) Security and robustness
13
Network Criteria
bull
1) Performance Transmission and response times - throughput and delay 2) Reliability How often the networks fail 3) Security Privacy and integrity of
communication Data recovery from breaches and data loss
14
Physical Structures
bull Types of connections
bull 1) Point to Point (P to P) Dedicated link to be utilized only by end devices
bull 2) Multipoint (Multidrop) Many end devices share the link capacity
15
Figure 13 Types of connections point-to-point and multipoint
16
Physical Topology
17
Figure 14 Categories of topology
18
Physical Topology
bull A) Mesh
bull Each device has dedicated point-to-point link to other devices Fully connected mesh will have n( n-1) 2 FD links ndash Where n = number of nodes
bull Advantages Fast communication Robust and Privacy (Security)
bull Disadvantages Cabling Space and cost
19
Figure 15 A fully connected mesh topology (five devices)
20
Physical Topology (cont)
bull B) Star
bull Devices are connected Point to Point to a central ldquoHubrdquo (Controller Exchanger)
bull Advantages Less cabling and HW ports two hops only
bull Disadvantage Not robust
21
Figure 16 A star topology connecting four stations
22
Figure 17 A bus topology connecting three stations
23
ndash C) Bus
bull Multipoint link as ldquobackbonerdquo for a network where devices have drop line to tap into the bus
Advantage Less Cabling bull Disadvantages Topology dependent limit
number of nodes on the bus due to signal power loss with distance not so robust
24
Figure 18 A ring topology connecting six stations
25
bull C) Ring Each device connects Point to Point with only two other devices in a left and right neighbors arrangement via a repeater
bull Advantages easy installation better fault isolation and robustness
bull Disadvantages N2 hops communication
26
Figure 19 A hybrid topology a star backbone with three bus networks
27
bull D) Hybrid bull Pizza ldquostarrdquo inside a ldquo ringrdquo
bull Pros Better robustness still low cost Delay is 1 hop (until the star is not with a ring cut max 2 bull Star of busses
28
Categories of Networks
bull Local Area Networks (LAN) Few Kilometers Connects devices (PCs printers servers) within the same room building company and campus
bull Topologies most used are bus ring and star
29
Figure 110 An isolated LAN connecting 12 computers to a hub in a closet
30
Categories of Networks(cont)
bull Wide Area Networks (WAN)
bull span a large geographical area about 100rsquos ndash 1000rsquos of Km
bull 1) Switched End users connected via a cloud of switches (subnet)
bull 2) Point-to Point Line leased from telephone company TV connecting users
to the ISP for Internet access
31
bull alternative technologies used includendash circuit switchingndash packet switchingndash frame relayndash Asynchronous Transfer Mode (ATM)
32
Circuit Switching
bull uses a dedicated communications path established for duration of conversation
bull comprising a sequence of physical links
bull with a dedicated logical channel
bull eg telephone network
33
Packet Switching
bull data sent out of sequence
bull small chunks (packets) of data at a time
bull packets passed from node to node between source and destination
bull used for terminal to computer and computer to computer communications
34
Frame Relay
bull packet switching systems have large overheads to compensate for errors
bull modern systems are more reliable
bull errors can be caught in end system
bull Frame Relay provides higher speeds
bull with most error control overhead removed
35
Asynchronous Transfer Mode(ATM)
bull evolution of frame relay
bull fixed packet (called cell) length
bull with little overhead for error control
bull anything from 10Mbps to Gbps
bull constant data rate using packet switching technique with multiple virtual circuits
36
Figure 111 WANs a switched WAN and a point-to-point WAN
37
Figure 112 A heterogeneous network made of four WANs and two LANs
38
Categories of Networks(cont)
bull Metropolitan Area Networks
bull MAN towncity
bull High-speed backbone linking multiple LANrsquos DSL TV cables
39
1-3 THE INTERNET1-3 THE INTERNET
The The InternetInternet has revolutionized many aspects of our has revolutionized many aspects of our daily lives It has affected the way we do business as well as the daily lives It has affected the way we do business as well as the way we spend our leisure time The Internet is a way we spend our leisure time The Internet is a communication system that has brought a wealth of communication system that has brought a wealth of information to our fingertips and organized it for our use information to our fingertips and organized it for our use
A Brief History The Internet Today (ISPs)
Topics discussed in this sectionTopics discussed in this section
40
The Internet
bull Internet evolved from ARPANETndash first operational packet networkndash applied to tactical radio amp satellite nets alsondash had a need for interoperabilityndash lead to standardized TCPIP protocols
41
The Internet
bull Huge number of interconnected Networks (100000rsquos) private organized egrsquo government schools research facilities in many countries
bull Collection of LANrsquoS MANrsquoS and WANrsquos ndash 1048708 The internet protocol stack is the TCPIP ndash 1048708 End users use the internet via Internet Service providers
(ISPs) which are of the following hierarchies
42
Figure 113 Hierarchical organization of the Internet
43
Internet Elements
44
Internet Architecture
45
Example Configuration
46
1-4 PROTOCOLS AND STANDARDS1-4 PROTOCOLS AND STANDARDS
In this section we define two widely used terms In this section we define two widely used terms protocolsprotocols and and standardsstandards First we define protocol which is synonymous with First we define protocol which is synonymous with rule Then we discuss standards which are agreed-upon rulesrule Then we discuss standards which are agreed-upon rules
ProtocolsStandardsStandards OrganizationsInternet Standards
Topics discussed in this sectionTopics discussed in this section
47
What is a protocol
Communications between computers requires very specific unambiguous rules A protocol is a set of rules that governs how two or more communicating parties are to interactExamples
Internet Protocol (IP)Transmission Control Protocol (TCP)HyperText Transfer Protocol (HTTP)Simple Mail Transfer Protocol (SMTP)
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
6
Chapter 1
Introduction
Copyright copy The McGraw-Hill Companies Inc Permission required for reproduction or display
7
1-1 DATA COMMUNICATIONS1-1 DATA COMMUNICATIONS
The term The term telecommunicationtelecommunication means communication at a means communication at a distance The word distance The word datadata refers to information presented in refers to information presented in whatever form is agreed upon by the parties creating and whatever form is agreed upon by the parties creating and using the data using the data Data communicationsData communications are the exchange of are the exchange of data between two devices via some form of transmission data between two devices via some form of transmission medium such as a wire cable medium such as a wire cable
ComponentsData RepresentationData Flow
Topics discussed in this sectionTopics discussed in this section
8
Figure 11 Five components of data communication
9
Data Representation
bull TEXT ndash unicode (32 bits to represent character)- ASCII
bull NUMBERS
bull IMAGES-composed of a matrix of pixel
bull AUDIO- recording or broadcasting of sound or music
bull VIDEO- recording or broadcasting of a
bull picture or movie
10
Figure 12 Data flow (simplex half-duplex and full-duplex)
11
1-2 NETWORKS1-2 NETWORKS
A A networknetwork is a set of devices (often referred to as is a set of devices (often referred to as nodesnodes) ) connected by communication connected by communication linkslinks A node can be a A node can be a computer printer or any other device capable of sending computer printer or any other device capable of sending andor receiving data generated by other nodes on the andor receiving data generated by other nodes on the networknetwork
Distributed ProcessingNetwork CriteriaPhysical StructuresNetwork ModelsCategories of NetworksInterconnection of Networks Internetwork
Topics discussed in this sectionTopics discussed in this section
12
NETWORKS
Set of nodes connected via physical links ndash 1) Distributing Processing ndash 2) Sharing Data and centralization ndash 3) Security and robustness
13
Network Criteria
bull
1) Performance Transmission and response times - throughput and delay 2) Reliability How often the networks fail 3) Security Privacy and integrity of
communication Data recovery from breaches and data loss
14
Physical Structures
bull Types of connections
bull 1) Point to Point (P to P) Dedicated link to be utilized only by end devices
bull 2) Multipoint (Multidrop) Many end devices share the link capacity
15
Figure 13 Types of connections point-to-point and multipoint
16
Physical Topology
17
Figure 14 Categories of topology
18
Physical Topology
bull A) Mesh
bull Each device has dedicated point-to-point link to other devices Fully connected mesh will have n( n-1) 2 FD links ndash Where n = number of nodes
bull Advantages Fast communication Robust and Privacy (Security)
bull Disadvantages Cabling Space and cost
19
Figure 15 A fully connected mesh topology (five devices)
20
Physical Topology (cont)
bull B) Star
bull Devices are connected Point to Point to a central ldquoHubrdquo (Controller Exchanger)
bull Advantages Less cabling and HW ports two hops only
bull Disadvantage Not robust
21
Figure 16 A star topology connecting four stations
22
Figure 17 A bus topology connecting three stations
23
ndash C) Bus
bull Multipoint link as ldquobackbonerdquo for a network where devices have drop line to tap into the bus
Advantage Less Cabling bull Disadvantages Topology dependent limit
number of nodes on the bus due to signal power loss with distance not so robust
24
Figure 18 A ring topology connecting six stations
25
bull C) Ring Each device connects Point to Point with only two other devices in a left and right neighbors arrangement via a repeater
bull Advantages easy installation better fault isolation and robustness
bull Disadvantages N2 hops communication
26
Figure 19 A hybrid topology a star backbone with three bus networks
27
bull D) Hybrid bull Pizza ldquostarrdquo inside a ldquo ringrdquo
bull Pros Better robustness still low cost Delay is 1 hop (until the star is not with a ring cut max 2 bull Star of busses
28
Categories of Networks
bull Local Area Networks (LAN) Few Kilometers Connects devices (PCs printers servers) within the same room building company and campus
bull Topologies most used are bus ring and star
29
Figure 110 An isolated LAN connecting 12 computers to a hub in a closet
30
Categories of Networks(cont)
bull Wide Area Networks (WAN)
bull span a large geographical area about 100rsquos ndash 1000rsquos of Km
bull 1) Switched End users connected via a cloud of switches (subnet)
bull 2) Point-to Point Line leased from telephone company TV connecting users
to the ISP for Internet access
31
bull alternative technologies used includendash circuit switchingndash packet switchingndash frame relayndash Asynchronous Transfer Mode (ATM)
32
Circuit Switching
bull uses a dedicated communications path established for duration of conversation
bull comprising a sequence of physical links
bull with a dedicated logical channel
bull eg telephone network
33
Packet Switching
bull data sent out of sequence
bull small chunks (packets) of data at a time
bull packets passed from node to node between source and destination
bull used for terminal to computer and computer to computer communications
34
Frame Relay
bull packet switching systems have large overheads to compensate for errors
bull modern systems are more reliable
bull errors can be caught in end system
bull Frame Relay provides higher speeds
bull with most error control overhead removed
35
Asynchronous Transfer Mode(ATM)
bull evolution of frame relay
bull fixed packet (called cell) length
bull with little overhead for error control
bull anything from 10Mbps to Gbps
bull constant data rate using packet switching technique with multiple virtual circuits
36
Figure 111 WANs a switched WAN and a point-to-point WAN
37
Figure 112 A heterogeneous network made of four WANs and two LANs
38
Categories of Networks(cont)
bull Metropolitan Area Networks
bull MAN towncity
bull High-speed backbone linking multiple LANrsquos DSL TV cables
39
1-3 THE INTERNET1-3 THE INTERNET
The The InternetInternet has revolutionized many aspects of our has revolutionized many aspects of our daily lives It has affected the way we do business as well as the daily lives It has affected the way we do business as well as the way we spend our leisure time The Internet is a way we spend our leisure time The Internet is a communication system that has brought a wealth of communication system that has brought a wealth of information to our fingertips and organized it for our use information to our fingertips and organized it for our use
A Brief History The Internet Today (ISPs)
Topics discussed in this sectionTopics discussed in this section
40
The Internet
bull Internet evolved from ARPANETndash first operational packet networkndash applied to tactical radio amp satellite nets alsondash had a need for interoperabilityndash lead to standardized TCPIP protocols
41
The Internet
bull Huge number of interconnected Networks (100000rsquos) private organized egrsquo government schools research facilities in many countries
bull Collection of LANrsquoS MANrsquoS and WANrsquos ndash 1048708 The internet protocol stack is the TCPIP ndash 1048708 End users use the internet via Internet Service providers
(ISPs) which are of the following hierarchies
42
Figure 113 Hierarchical organization of the Internet
43
Internet Elements
44
Internet Architecture
45
Example Configuration
46
1-4 PROTOCOLS AND STANDARDS1-4 PROTOCOLS AND STANDARDS
In this section we define two widely used terms In this section we define two widely used terms protocolsprotocols and and standardsstandards First we define protocol which is synonymous with First we define protocol which is synonymous with rule Then we discuss standards which are agreed-upon rulesrule Then we discuss standards which are agreed-upon rules
ProtocolsStandardsStandards OrganizationsInternet Standards
Topics discussed in this sectionTopics discussed in this section
47
What is a protocol
Communications between computers requires very specific unambiguous rules A protocol is a set of rules that governs how two or more communicating parties are to interactExamples
Internet Protocol (IP)Transmission Control Protocol (TCP)HyperText Transfer Protocol (HTTP)Simple Mail Transfer Protocol (SMTP)
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
7
1-1 DATA COMMUNICATIONS1-1 DATA COMMUNICATIONS
The term The term telecommunicationtelecommunication means communication at a means communication at a distance The word distance The word datadata refers to information presented in refers to information presented in whatever form is agreed upon by the parties creating and whatever form is agreed upon by the parties creating and using the data using the data Data communicationsData communications are the exchange of are the exchange of data between two devices via some form of transmission data between two devices via some form of transmission medium such as a wire cable medium such as a wire cable
ComponentsData RepresentationData Flow
Topics discussed in this sectionTopics discussed in this section
8
Figure 11 Five components of data communication
9
Data Representation
bull TEXT ndash unicode (32 bits to represent character)- ASCII
bull NUMBERS
bull IMAGES-composed of a matrix of pixel
bull AUDIO- recording or broadcasting of sound or music
bull VIDEO- recording or broadcasting of a
bull picture or movie
10
Figure 12 Data flow (simplex half-duplex and full-duplex)
11
1-2 NETWORKS1-2 NETWORKS
A A networknetwork is a set of devices (often referred to as is a set of devices (often referred to as nodesnodes) ) connected by communication connected by communication linkslinks A node can be a A node can be a computer printer or any other device capable of sending computer printer or any other device capable of sending andor receiving data generated by other nodes on the andor receiving data generated by other nodes on the networknetwork
Distributed ProcessingNetwork CriteriaPhysical StructuresNetwork ModelsCategories of NetworksInterconnection of Networks Internetwork
Topics discussed in this sectionTopics discussed in this section
12
NETWORKS
Set of nodes connected via physical links ndash 1) Distributing Processing ndash 2) Sharing Data and centralization ndash 3) Security and robustness
13
Network Criteria
bull
1) Performance Transmission and response times - throughput and delay 2) Reliability How often the networks fail 3) Security Privacy and integrity of
communication Data recovery from breaches and data loss
14
Physical Structures
bull Types of connections
bull 1) Point to Point (P to P) Dedicated link to be utilized only by end devices
bull 2) Multipoint (Multidrop) Many end devices share the link capacity
15
Figure 13 Types of connections point-to-point and multipoint
16
Physical Topology
17
Figure 14 Categories of topology
18
Physical Topology
bull A) Mesh
bull Each device has dedicated point-to-point link to other devices Fully connected mesh will have n( n-1) 2 FD links ndash Where n = number of nodes
bull Advantages Fast communication Robust and Privacy (Security)
bull Disadvantages Cabling Space and cost
19
Figure 15 A fully connected mesh topology (five devices)
20
Physical Topology (cont)
bull B) Star
bull Devices are connected Point to Point to a central ldquoHubrdquo (Controller Exchanger)
bull Advantages Less cabling and HW ports two hops only
bull Disadvantage Not robust
21
Figure 16 A star topology connecting four stations
22
Figure 17 A bus topology connecting three stations
23
ndash C) Bus
bull Multipoint link as ldquobackbonerdquo for a network where devices have drop line to tap into the bus
Advantage Less Cabling bull Disadvantages Topology dependent limit
number of nodes on the bus due to signal power loss with distance not so robust
24
Figure 18 A ring topology connecting six stations
25
bull C) Ring Each device connects Point to Point with only two other devices in a left and right neighbors arrangement via a repeater
bull Advantages easy installation better fault isolation and robustness
bull Disadvantages N2 hops communication
26
Figure 19 A hybrid topology a star backbone with three bus networks
27
bull D) Hybrid bull Pizza ldquostarrdquo inside a ldquo ringrdquo
bull Pros Better robustness still low cost Delay is 1 hop (until the star is not with a ring cut max 2 bull Star of busses
28
Categories of Networks
bull Local Area Networks (LAN) Few Kilometers Connects devices (PCs printers servers) within the same room building company and campus
bull Topologies most used are bus ring and star
29
Figure 110 An isolated LAN connecting 12 computers to a hub in a closet
30
Categories of Networks(cont)
bull Wide Area Networks (WAN)
bull span a large geographical area about 100rsquos ndash 1000rsquos of Km
bull 1) Switched End users connected via a cloud of switches (subnet)
bull 2) Point-to Point Line leased from telephone company TV connecting users
to the ISP for Internet access
31
bull alternative technologies used includendash circuit switchingndash packet switchingndash frame relayndash Asynchronous Transfer Mode (ATM)
32
Circuit Switching
bull uses a dedicated communications path established for duration of conversation
bull comprising a sequence of physical links
bull with a dedicated logical channel
bull eg telephone network
33
Packet Switching
bull data sent out of sequence
bull small chunks (packets) of data at a time
bull packets passed from node to node between source and destination
bull used for terminal to computer and computer to computer communications
34
Frame Relay
bull packet switching systems have large overheads to compensate for errors
bull modern systems are more reliable
bull errors can be caught in end system
bull Frame Relay provides higher speeds
bull with most error control overhead removed
35
Asynchronous Transfer Mode(ATM)
bull evolution of frame relay
bull fixed packet (called cell) length
bull with little overhead for error control
bull anything from 10Mbps to Gbps
bull constant data rate using packet switching technique with multiple virtual circuits
36
Figure 111 WANs a switched WAN and a point-to-point WAN
37
Figure 112 A heterogeneous network made of four WANs and two LANs
38
Categories of Networks(cont)
bull Metropolitan Area Networks
bull MAN towncity
bull High-speed backbone linking multiple LANrsquos DSL TV cables
39
1-3 THE INTERNET1-3 THE INTERNET
The The InternetInternet has revolutionized many aspects of our has revolutionized many aspects of our daily lives It has affected the way we do business as well as the daily lives It has affected the way we do business as well as the way we spend our leisure time The Internet is a way we spend our leisure time The Internet is a communication system that has brought a wealth of communication system that has brought a wealth of information to our fingertips and organized it for our use information to our fingertips and organized it for our use
A Brief History The Internet Today (ISPs)
Topics discussed in this sectionTopics discussed in this section
40
The Internet
bull Internet evolved from ARPANETndash first operational packet networkndash applied to tactical radio amp satellite nets alsondash had a need for interoperabilityndash lead to standardized TCPIP protocols
41
The Internet
bull Huge number of interconnected Networks (100000rsquos) private organized egrsquo government schools research facilities in many countries
bull Collection of LANrsquoS MANrsquoS and WANrsquos ndash 1048708 The internet protocol stack is the TCPIP ndash 1048708 End users use the internet via Internet Service providers
(ISPs) which are of the following hierarchies
42
Figure 113 Hierarchical organization of the Internet
43
Internet Elements
44
Internet Architecture
45
Example Configuration
46
1-4 PROTOCOLS AND STANDARDS1-4 PROTOCOLS AND STANDARDS
In this section we define two widely used terms In this section we define two widely used terms protocolsprotocols and and standardsstandards First we define protocol which is synonymous with First we define protocol which is synonymous with rule Then we discuss standards which are agreed-upon rulesrule Then we discuss standards which are agreed-upon rules
ProtocolsStandardsStandards OrganizationsInternet Standards
Topics discussed in this sectionTopics discussed in this section
47
What is a protocol
Communications between computers requires very specific unambiguous rules A protocol is a set of rules that governs how two or more communicating parties are to interactExamples
Internet Protocol (IP)Transmission Control Protocol (TCP)HyperText Transfer Protocol (HTTP)Simple Mail Transfer Protocol (SMTP)
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
8
Figure 11 Five components of data communication
9
Data Representation
bull TEXT ndash unicode (32 bits to represent character)- ASCII
bull NUMBERS
bull IMAGES-composed of a matrix of pixel
bull AUDIO- recording or broadcasting of sound or music
bull VIDEO- recording or broadcasting of a
bull picture or movie
10
Figure 12 Data flow (simplex half-duplex and full-duplex)
11
1-2 NETWORKS1-2 NETWORKS
A A networknetwork is a set of devices (often referred to as is a set of devices (often referred to as nodesnodes) ) connected by communication connected by communication linkslinks A node can be a A node can be a computer printer or any other device capable of sending computer printer or any other device capable of sending andor receiving data generated by other nodes on the andor receiving data generated by other nodes on the networknetwork
Distributed ProcessingNetwork CriteriaPhysical StructuresNetwork ModelsCategories of NetworksInterconnection of Networks Internetwork
Topics discussed in this sectionTopics discussed in this section
12
NETWORKS
Set of nodes connected via physical links ndash 1) Distributing Processing ndash 2) Sharing Data and centralization ndash 3) Security and robustness
13
Network Criteria
bull
1) Performance Transmission and response times - throughput and delay 2) Reliability How often the networks fail 3) Security Privacy and integrity of
communication Data recovery from breaches and data loss
14
Physical Structures
bull Types of connections
bull 1) Point to Point (P to P) Dedicated link to be utilized only by end devices
bull 2) Multipoint (Multidrop) Many end devices share the link capacity
15
Figure 13 Types of connections point-to-point and multipoint
16
Physical Topology
17
Figure 14 Categories of topology
18
Physical Topology
bull A) Mesh
bull Each device has dedicated point-to-point link to other devices Fully connected mesh will have n( n-1) 2 FD links ndash Where n = number of nodes
bull Advantages Fast communication Robust and Privacy (Security)
bull Disadvantages Cabling Space and cost
19
Figure 15 A fully connected mesh topology (five devices)
20
Physical Topology (cont)
bull B) Star
bull Devices are connected Point to Point to a central ldquoHubrdquo (Controller Exchanger)
bull Advantages Less cabling and HW ports two hops only
bull Disadvantage Not robust
21
Figure 16 A star topology connecting four stations
22
Figure 17 A bus topology connecting three stations
23
ndash C) Bus
bull Multipoint link as ldquobackbonerdquo for a network where devices have drop line to tap into the bus
Advantage Less Cabling bull Disadvantages Topology dependent limit
number of nodes on the bus due to signal power loss with distance not so robust
24
Figure 18 A ring topology connecting six stations
25
bull C) Ring Each device connects Point to Point with only two other devices in a left and right neighbors arrangement via a repeater
bull Advantages easy installation better fault isolation and robustness
bull Disadvantages N2 hops communication
26
Figure 19 A hybrid topology a star backbone with three bus networks
27
bull D) Hybrid bull Pizza ldquostarrdquo inside a ldquo ringrdquo
bull Pros Better robustness still low cost Delay is 1 hop (until the star is not with a ring cut max 2 bull Star of busses
28
Categories of Networks
bull Local Area Networks (LAN) Few Kilometers Connects devices (PCs printers servers) within the same room building company and campus
bull Topologies most used are bus ring and star
29
Figure 110 An isolated LAN connecting 12 computers to a hub in a closet
30
Categories of Networks(cont)
bull Wide Area Networks (WAN)
bull span a large geographical area about 100rsquos ndash 1000rsquos of Km
bull 1) Switched End users connected via a cloud of switches (subnet)
bull 2) Point-to Point Line leased from telephone company TV connecting users
to the ISP for Internet access
31
bull alternative technologies used includendash circuit switchingndash packet switchingndash frame relayndash Asynchronous Transfer Mode (ATM)
32
Circuit Switching
bull uses a dedicated communications path established for duration of conversation
bull comprising a sequence of physical links
bull with a dedicated logical channel
bull eg telephone network
33
Packet Switching
bull data sent out of sequence
bull small chunks (packets) of data at a time
bull packets passed from node to node between source and destination
bull used for terminal to computer and computer to computer communications
34
Frame Relay
bull packet switching systems have large overheads to compensate for errors
bull modern systems are more reliable
bull errors can be caught in end system
bull Frame Relay provides higher speeds
bull with most error control overhead removed
35
Asynchronous Transfer Mode(ATM)
bull evolution of frame relay
bull fixed packet (called cell) length
bull with little overhead for error control
bull anything from 10Mbps to Gbps
bull constant data rate using packet switching technique with multiple virtual circuits
36
Figure 111 WANs a switched WAN and a point-to-point WAN
37
Figure 112 A heterogeneous network made of four WANs and two LANs
38
Categories of Networks(cont)
bull Metropolitan Area Networks
bull MAN towncity
bull High-speed backbone linking multiple LANrsquos DSL TV cables
39
1-3 THE INTERNET1-3 THE INTERNET
The The InternetInternet has revolutionized many aspects of our has revolutionized many aspects of our daily lives It has affected the way we do business as well as the daily lives It has affected the way we do business as well as the way we spend our leisure time The Internet is a way we spend our leisure time The Internet is a communication system that has brought a wealth of communication system that has brought a wealth of information to our fingertips and organized it for our use information to our fingertips and organized it for our use
A Brief History The Internet Today (ISPs)
Topics discussed in this sectionTopics discussed in this section
40
The Internet
bull Internet evolved from ARPANETndash first operational packet networkndash applied to tactical radio amp satellite nets alsondash had a need for interoperabilityndash lead to standardized TCPIP protocols
41
The Internet
bull Huge number of interconnected Networks (100000rsquos) private organized egrsquo government schools research facilities in many countries
bull Collection of LANrsquoS MANrsquoS and WANrsquos ndash 1048708 The internet protocol stack is the TCPIP ndash 1048708 End users use the internet via Internet Service providers
(ISPs) which are of the following hierarchies
42
Figure 113 Hierarchical organization of the Internet
43
Internet Elements
44
Internet Architecture
45
Example Configuration
46
1-4 PROTOCOLS AND STANDARDS1-4 PROTOCOLS AND STANDARDS
In this section we define two widely used terms In this section we define two widely used terms protocolsprotocols and and standardsstandards First we define protocol which is synonymous with First we define protocol which is synonymous with rule Then we discuss standards which are agreed-upon rulesrule Then we discuss standards which are agreed-upon rules
ProtocolsStandardsStandards OrganizationsInternet Standards
Topics discussed in this sectionTopics discussed in this section
47
What is a protocol
Communications between computers requires very specific unambiguous rules A protocol is a set of rules that governs how two or more communicating parties are to interactExamples
Internet Protocol (IP)Transmission Control Protocol (TCP)HyperText Transfer Protocol (HTTP)Simple Mail Transfer Protocol (SMTP)
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
9
Data Representation
bull TEXT ndash unicode (32 bits to represent character)- ASCII
bull NUMBERS
bull IMAGES-composed of a matrix of pixel
bull AUDIO- recording or broadcasting of sound or music
bull VIDEO- recording or broadcasting of a
bull picture or movie
10
Figure 12 Data flow (simplex half-duplex and full-duplex)
11
1-2 NETWORKS1-2 NETWORKS
A A networknetwork is a set of devices (often referred to as is a set of devices (often referred to as nodesnodes) ) connected by communication connected by communication linkslinks A node can be a A node can be a computer printer or any other device capable of sending computer printer or any other device capable of sending andor receiving data generated by other nodes on the andor receiving data generated by other nodes on the networknetwork
Distributed ProcessingNetwork CriteriaPhysical StructuresNetwork ModelsCategories of NetworksInterconnection of Networks Internetwork
Topics discussed in this sectionTopics discussed in this section
12
NETWORKS
Set of nodes connected via physical links ndash 1) Distributing Processing ndash 2) Sharing Data and centralization ndash 3) Security and robustness
13
Network Criteria
bull
1) Performance Transmission and response times - throughput and delay 2) Reliability How often the networks fail 3) Security Privacy and integrity of
communication Data recovery from breaches and data loss
14
Physical Structures
bull Types of connections
bull 1) Point to Point (P to P) Dedicated link to be utilized only by end devices
bull 2) Multipoint (Multidrop) Many end devices share the link capacity
15
Figure 13 Types of connections point-to-point and multipoint
16
Physical Topology
17
Figure 14 Categories of topology
18
Physical Topology
bull A) Mesh
bull Each device has dedicated point-to-point link to other devices Fully connected mesh will have n( n-1) 2 FD links ndash Where n = number of nodes
bull Advantages Fast communication Robust and Privacy (Security)
bull Disadvantages Cabling Space and cost
19
Figure 15 A fully connected mesh topology (five devices)
20
Physical Topology (cont)
bull B) Star
bull Devices are connected Point to Point to a central ldquoHubrdquo (Controller Exchanger)
bull Advantages Less cabling and HW ports two hops only
bull Disadvantage Not robust
21
Figure 16 A star topology connecting four stations
22
Figure 17 A bus topology connecting three stations
23
ndash C) Bus
bull Multipoint link as ldquobackbonerdquo for a network where devices have drop line to tap into the bus
Advantage Less Cabling bull Disadvantages Topology dependent limit
number of nodes on the bus due to signal power loss with distance not so robust
24
Figure 18 A ring topology connecting six stations
25
bull C) Ring Each device connects Point to Point with only two other devices in a left and right neighbors arrangement via a repeater
bull Advantages easy installation better fault isolation and robustness
bull Disadvantages N2 hops communication
26
Figure 19 A hybrid topology a star backbone with three bus networks
27
bull D) Hybrid bull Pizza ldquostarrdquo inside a ldquo ringrdquo
bull Pros Better robustness still low cost Delay is 1 hop (until the star is not with a ring cut max 2 bull Star of busses
28
Categories of Networks
bull Local Area Networks (LAN) Few Kilometers Connects devices (PCs printers servers) within the same room building company and campus
bull Topologies most used are bus ring and star
29
Figure 110 An isolated LAN connecting 12 computers to a hub in a closet
30
Categories of Networks(cont)
bull Wide Area Networks (WAN)
bull span a large geographical area about 100rsquos ndash 1000rsquos of Km
bull 1) Switched End users connected via a cloud of switches (subnet)
bull 2) Point-to Point Line leased from telephone company TV connecting users
to the ISP for Internet access
31
bull alternative technologies used includendash circuit switchingndash packet switchingndash frame relayndash Asynchronous Transfer Mode (ATM)
32
Circuit Switching
bull uses a dedicated communications path established for duration of conversation
bull comprising a sequence of physical links
bull with a dedicated logical channel
bull eg telephone network
33
Packet Switching
bull data sent out of sequence
bull small chunks (packets) of data at a time
bull packets passed from node to node between source and destination
bull used for terminal to computer and computer to computer communications
34
Frame Relay
bull packet switching systems have large overheads to compensate for errors
bull modern systems are more reliable
bull errors can be caught in end system
bull Frame Relay provides higher speeds
bull with most error control overhead removed
35
Asynchronous Transfer Mode(ATM)
bull evolution of frame relay
bull fixed packet (called cell) length
bull with little overhead for error control
bull anything from 10Mbps to Gbps
bull constant data rate using packet switching technique with multiple virtual circuits
36
Figure 111 WANs a switched WAN and a point-to-point WAN
37
Figure 112 A heterogeneous network made of four WANs and two LANs
38
Categories of Networks(cont)
bull Metropolitan Area Networks
bull MAN towncity
bull High-speed backbone linking multiple LANrsquos DSL TV cables
39
1-3 THE INTERNET1-3 THE INTERNET
The The InternetInternet has revolutionized many aspects of our has revolutionized many aspects of our daily lives It has affected the way we do business as well as the daily lives It has affected the way we do business as well as the way we spend our leisure time The Internet is a way we spend our leisure time The Internet is a communication system that has brought a wealth of communication system that has brought a wealth of information to our fingertips and organized it for our use information to our fingertips and organized it for our use
A Brief History The Internet Today (ISPs)
Topics discussed in this sectionTopics discussed in this section
40
The Internet
bull Internet evolved from ARPANETndash first operational packet networkndash applied to tactical radio amp satellite nets alsondash had a need for interoperabilityndash lead to standardized TCPIP protocols
41
The Internet
bull Huge number of interconnected Networks (100000rsquos) private organized egrsquo government schools research facilities in many countries
bull Collection of LANrsquoS MANrsquoS and WANrsquos ndash 1048708 The internet protocol stack is the TCPIP ndash 1048708 End users use the internet via Internet Service providers
(ISPs) which are of the following hierarchies
42
Figure 113 Hierarchical organization of the Internet
43
Internet Elements
44
Internet Architecture
45
Example Configuration
46
1-4 PROTOCOLS AND STANDARDS1-4 PROTOCOLS AND STANDARDS
In this section we define two widely used terms In this section we define two widely used terms protocolsprotocols and and standardsstandards First we define protocol which is synonymous with First we define protocol which is synonymous with rule Then we discuss standards which are agreed-upon rulesrule Then we discuss standards which are agreed-upon rules
ProtocolsStandardsStandards OrganizationsInternet Standards
Topics discussed in this sectionTopics discussed in this section
47
What is a protocol
Communications between computers requires very specific unambiguous rules A protocol is a set of rules that governs how two or more communicating parties are to interactExamples
Internet Protocol (IP)Transmission Control Protocol (TCP)HyperText Transfer Protocol (HTTP)Simple Mail Transfer Protocol (SMTP)
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
10
Figure 12 Data flow (simplex half-duplex and full-duplex)
11
1-2 NETWORKS1-2 NETWORKS
A A networknetwork is a set of devices (often referred to as is a set of devices (often referred to as nodesnodes) ) connected by communication connected by communication linkslinks A node can be a A node can be a computer printer or any other device capable of sending computer printer or any other device capable of sending andor receiving data generated by other nodes on the andor receiving data generated by other nodes on the networknetwork
Distributed ProcessingNetwork CriteriaPhysical StructuresNetwork ModelsCategories of NetworksInterconnection of Networks Internetwork
Topics discussed in this sectionTopics discussed in this section
12
NETWORKS
Set of nodes connected via physical links ndash 1) Distributing Processing ndash 2) Sharing Data and centralization ndash 3) Security and robustness
13
Network Criteria
bull
1) Performance Transmission and response times - throughput and delay 2) Reliability How often the networks fail 3) Security Privacy and integrity of
communication Data recovery from breaches and data loss
14
Physical Structures
bull Types of connections
bull 1) Point to Point (P to P) Dedicated link to be utilized only by end devices
bull 2) Multipoint (Multidrop) Many end devices share the link capacity
15
Figure 13 Types of connections point-to-point and multipoint
16
Physical Topology
17
Figure 14 Categories of topology
18
Physical Topology
bull A) Mesh
bull Each device has dedicated point-to-point link to other devices Fully connected mesh will have n( n-1) 2 FD links ndash Where n = number of nodes
bull Advantages Fast communication Robust and Privacy (Security)
bull Disadvantages Cabling Space and cost
19
Figure 15 A fully connected mesh topology (five devices)
20
Physical Topology (cont)
bull B) Star
bull Devices are connected Point to Point to a central ldquoHubrdquo (Controller Exchanger)
bull Advantages Less cabling and HW ports two hops only
bull Disadvantage Not robust
21
Figure 16 A star topology connecting four stations
22
Figure 17 A bus topology connecting three stations
23
ndash C) Bus
bull Multipoint link as ldquobackbonerdquo for a network where devices have drop line to tap into the bus
Advantage Less Cabling bull Disadvantages Topology dependent limit
number of nodes on the bus due to signal power loss with distance not so robust
24
Figure 18 A ring topology connecting six stations
25
bull C) Ring Each device connects Point to Point with only two other devices in a left and right neighbors arrangement via a repeater
bull Advantages easy installation better fault isolation and robustness
bull Disadvantages N2 hops communication
26
Figure 19 A hybrid topology a star backbone with three bus networks
27
bull D) Hybrid bull Pizza ldquostarrdquo inside a ldquo ringrdquo
bull Pros Better robustness still low cost Delay is 1 hop (until the star is not with a ring cut max 2 bull Star of busses
28
Categories of Networks
bull Local Area Networks (LAN) Few Kilometers Connects devices (PCs printers servers) within the same room building company and campus
bull Topologies most used are bus ring and star
29
Figure 110 An isolated LAN connecting 12 computers to a hub in a closet
30
Categories of Networks(cont)
bull Wide Area Networks (WAN)
bull span a large geographical area about 100rsquos ndash 1000rsquos of Km
bull 1) Switched End users connected via a cloud of switches (subnet)
bull 2) Point-to Point Line leased from telephone company TV connecting users
to the ISP for Internet access
31
bull alternative technologies used includendash circuit switchingndash packet switchingndash frame relayndash Asynchronous Transfer Mode (ATM)
32
Circuit Switching
bull uses a dedicated communications path established for duration of conversation
bull comprising a sequence of physical links
bull with a dedicated logical channel
bull eg telephone network
33
Packet Switching
bull data sent out of sequence
bull small chunks (packets) of data at a time
bull packets passed from node to node between source and destination
bull used for terminal to computer and computer to computer communications
34
Frame Relay
bull packet switching systems have large overheads to compensate for errors
bull modern systems are more reliable
bull errors can be caught in end system
bull Frame Relay provides higher speeds
bull with most error control overhead removed
35
Asynchronous Transfer Mode(ATM)
bull evolution of frame relay
bull fixed packet (called cell) length
bull with little overhead for error control
bull anything from 10Mbps to Gbps
bull constant data rate using packet switching technique with multiple virtual circuits
36
Figure 111 WANs a switched WAN and a point-to-point WAN
37
Figure 112 A heterogeneous network made of four WANs and two LANs
38
Categories of Networks(cont)
bull Metropolitan Area Networks
bull MAN towncity
bull High-speed backbone linking multiple LANrsquos DSL TV cables
39
1-3 THE INTERNET1-3 THE INTERNET
The The InternetInternet has revolutionized many aspects of our has revolutionized many aspects of our daily lives It has affected the way we do business as well as the daily lives It has affected the way we do business as well as the way we spend our leisure time The Internet is a way we spend our leisure time The Internet is a communication system that has brought a wealth of communication system that has brought a wealth of information to our fingertips and organized it for our use information to our fingertips and organized it for our use
A Brief History The Internet Today (ISPs)
Topics discussed in this sectionTopics discussed in this section
40
The Internet
bull Internet evolved from ARPANETndash first operational packet networkndash applied to tactical radio amp satellite nets alsondash had a need for interoperabilityndash lead to standardized TCPIP protocols
41
The Internet
bull Huge number of interconnected Networks (100000rsquos) private organized egrsquo government schools research facilities in many countries
bull Collection of LANrsquoS MANrsquoS and WANrsquos ndash 1048708 The internet protocol stack is the TCPIP ndash 1048708 End users use the internet via Internet Service providers
(ISPs) which are of the following hierarchies
42
Figure 113 Hierarchical organization of the Internet
43
Internet Elements
44
Internet Architecture
45
Example Configuration
46
1-4 PROTOCOLS AND STANDARDS1-4 PROTOCOLS AND STANDARDS
In this section we define two widely used terms In this section we define two widely used terms protocolsprotocols and and standardsstandards First we define protocol which is synonymous with First we define protocol which is synonymous with rule Then we discuss standards which are agreed-upon rulesrule Then we discuss standards which are agreed-upon rules
ProtocolsStandardsStandards OrganizationsInternet Standards
Topics discussed in this sectionTopics discussed in this section
47
What is a protocol
Communications between computers requires very specific unambiguous rules A protocol is a set of rules that governs how two or more communicating parties are to interactExamples
Internet Protocol (IP)Transmission Control Protocol (TCP)HyperText Transfer Protocol (HTTP)Simple Mail Transfer Protocol (SMTP)
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
11
1-2 NETWORKS1-2 NETWORKS
A A networknetwork is a set of devices (often referred to as is a set of devices (often referred to as nodesnodes) ) connected by communication connected by communication linkslinks A node can be a A node can be a computer printer or any other device capable of sending computer printer or any other device capable of sending andor receiving data generated by other nodes on the andor receiving data generated by other nodes on the networknetwork
Distributed ProcessingNetwork CriteriaPhysical StructuresNetwork ModelsCategories of NetworksInterconnection of Networks Internetwork
Topics discussed in this sectionTopics discussed in this section
12
NETWORKS
Set of nodes connected via physical links ndash 1) Distributing Processing ndash 2) Sharing Data and centralization ndash 3) Security and robustness
13
Network Criteria
bull
1) Performance Transmission and response times - throughput and delay 2) Reliability How often the networks fail 3) Security Privacy and integrity of
communication Data recovery from breaches and data loss
14
Physical Structures
bull Types of connections
bull 1) Point to Point (P to P) Dedicated link to be utilized only by end devices
bull 2) Multipoint (Multidrop) Many end devices share the link capacity
15
Figure 13 Types of connections point-to-point and multipoint
16
Physical Topology
17
Figure 14 Categories of topology
18
Physical Topology
bull A) Mesh
bull Each device has dedicated point-to-point link to other devices Fully connected mesh will have n( n-1) 2 FD links ndash Where n = number of nodes
bull Advantages Fast communication Robust and Privacy (Security)
bull Disadvantages Cabling Space and cost
19
Figure 15 A fully connected mesh topology (five devices)
20
Physical Topology (cont)
bull B) Star
bull Devices are connected Point to Point to a central ldquoHubrdquo (Controller Exchanger)
bull Advantages Less cabling and HW ports two hops only
bull Disadvantage Not robust
21
Figure 16 A star topology connecting four stations
22
Figure 17 A bus topology connecting three stations
23
ndash C) Bus
bull Multipoint link as ldquobackbonerdquo for a network where devices have drop line to tap into the bus
Advantage Less Cabling bull Disadvantages Topology dependent limit
number of nodes on the bus due to signal power loss with distance not so robust
24
Figure 18 A ring topology connecting six stations
25
bull C) Ring Each device connects Point to Point with only two other devices in a left and right neighbors arrangement via a repeater
bull Advantages easy installation better fault isolation and robustness
bull Disadvantages N2 hops communication
26
Figure 19 A hybrid topology a star backbone with three bus networks
27
bull D) Hybrid bull Pizza ldquostarrdquo inside a ldquo ringrdquo
bull Pros Better robustness still low cost Delay is 1 hop (until the star is not with a ring cut max 2 bull Star of busses
28
Categories of Networks
bull Local Area Networks (LAN) Few Kilometers Connects devices (PCs printers servers) within the same room building company and campus
bull Topologies most used are bus ring and star
29
Figure 110 An isolated LAN connecting 12 computers to a hub in a closet
30
Categories of Networks(cont)
bull Wide Area Networks (WAN)
bull span a large geographical area about 100rsquos ndash 1000rsquos of Km
bull 1) Switched End users connected via a cloud of switches (subnet)
bull 2) Point-to Point Line leased from telephone company TV connecting users
to the ISP for Internet access
31
bull alternative technologies used includendash circuit switchingndash packet switchingndash frame relayndash Asynchronous Transfer Mode (ATM)
32
Circuit Switching
bull uses a dedicated communications path established for duration of conversation
bull comprising a sequence of physical links
bull with a dedicated logical channel
bull eg telephone network
33
Packet Switching
bull data sent out of sequence
bull small chunks (packets) of data at a time
bull packets passed from node to node between source and destination
bull used for terminal to computer and computer to computer communications
34
Frame Relay
bull packet switching systems have large overheads to compensate for errors
bull modern systems are more reliable
bull errors can be caught in end system
bull Frame Relay provides higher speeds
bull with most error control overhead removed
35
Asynchronous Transfer Mode(ATM)
bull evolution of frame relay
bull fixed packet (called cell) length
bull with little overhead for error control
bull anything from 10Mbps to Gbps
bull constant data rate using packet switching technique with multiple virtual circuits
36
Figure 111 WANs a switched WAN and a point-to-point WAN
37
Figure 112 A heterogeneous network made of four WANs and two LANs
38
Categories of Networks(cont)
bull Metropolitan Area Networks
bull MAN towncity
bull High-speed backbone linking multiple LANrsquos DSL TV cables
39
1-3 THE INTERNET1-3 THE INTERNET
The The InternetInternet has revolutionized many aspects of our has revolutionized many aspects of our daily lives It has affected the way we do business as well as the daily lives It has affected the way we do business as well as the way we spend our leisure time The Internet is a way we spend our leisure time The Internet is a communication system that has brought a wealth of communication system that has brought a wealth of information to our fingertips and organized it for our use information to our fingertips and organized it for our use
A Brief History The Internet Today (ISPs)
Topics discussed in this sectionTopics discussed in this section
40
The Internet
bull Internet evolved from ARPANETndash first operational packet networkndash applied to tactical radio amp satellite nets alsondash had a need for interoperabilityndash lead to standardized TCPIP protocols
41
The Internet
bull Huge number of interconnected Networks (100000rsquos) private organized egrsquo government schools research facilities in many countries
bull Collection of LANrsquoS MANrsquoS and WANrsquos ndash 1048708 The internet protocol stack is the TCPIP ndash 1048708 End users use the internet via Internet Service providers
(ISPs) which are of the following hierarchies
42
Figure 113 Hierarchical organization of the Internet
43
Internet Elements
44
Internet Architecture
45
Example Configuration
46
1-4 PROTOCOLS AND STANDARDS1-4 PROTOCOLS AND STANDARDS
In this section we define two widely used terms In this section we define two widely used terms protocolsprotocols and and standardsstandards First we define protocol which is synonymous with First we define protocol which is synonymous with rule Then we discuss standards which are agreed-upon rulesrule Then we discuss standards which are agreed-upon rules
ProtocolsStandardsStandards OrganizationsInternet Standards
Topics discussed in this sectionTopics discussed in this section
47
What is a protocol
Communications between computers requires very specific unambiguous rules A protocol is a set of rules that governs how two or more communicating parties are to interactExamples
Internet Protocol (IP)Transmission Control Protocol (TCP)HyperText Transfer Protocol (HTTP)Simple Mail Transfer Protocol (SMTP)
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
12
NETWORKS
Set of nodes connected via physical links ndash 1) Distributing Processing ndash 2) Sharing Data and centralization ndash 3) Security and robustness
13
Network Criteria
bull
1) Performance Transmission and response times - throughput and delay 2) Reliability How often the networks fail 3) Security Privacy and integrity of
communication Data recovery from breaches and data loss
14
Physical Structures
bull Types of connections
bull 1) Point to Point (P to P) Dedicated link to be utilized only by end devices
bull 2) Multipoint (Multidrop) Many end devices share the link capacity
15
Figure 13 Types of connections point-to-point and multipoint
16
Physical Topology
17
Figure 14 Categories of topology
18
Physical Topology
bull A) Mesh
bull Each device has dedicated point-to-point link to other devices Fully connected mesh will have n( n-1) 2 FD links ndash Where n = number of nodes
bull Advantages Fast communication Robust and Privacy (Security)
bull Disadvantages Cabling Space and cost
19
Figure 15 A fully connected mesh topology (five devices)
20
Physical Topology (cont)
bull B) Star
bull Devices are connected Point to Point to a central ldquoHubrdquo (Controller Exchanger)
bull Advantages Less cabling and HW ports two hops only
bull Disadvantage Not robust
21
Figure 16 A star topology connecting four stations
22
Figure 17 A bus topology connecting three stations
23
ndash C) Bus
bull Multipoint link as ldquobackbonerdquo for a network where devices have drop line to tap into the bus
Advantage Less Cabling bull Disadvantages Topology dependent limit
number of nodes on the bus due to signal power loss with distance not so robust
24
Figure 18 A ring topology connecting six stations
25
bull C) Ring Each device connects Point to Point with only two other devices in a left and right neighbors arrangement via a repeater
bull Advantages easy installation better fault isolation and robustness
bull Disadvantages N2 hops communication
26
Figure 19 A hybrid topology a star backbone with three bus networks
27
bull D) Hybrid bull Pizza ldquostarrdquo inside a ldquo ringrdquo
bull Pros Better robustness still low cost Delay is 1 hop (until the star is not with a ring cut max 2 bull Star of busses
28
Categories of Networks
bull Local Area Networks (LAN) Few Kilometers Connects devices (PCs printers servers) within the same room building company and campus
bull Topologies most used are bus ring and star
29
Figure 110 An isolated LAN connecting 12 computers to a hub in a closet
30
Categories of Networks(cont)
bull Wide Area Networks (WAN)
bull span a large geographical area about 100rsquos ndash 1000rsquos of Km
bull 1) Switched End users connected via a cloud of switches (subnet)
bull 2) Point-to Point Line leased from telephone company TV connecting users
to the ISP for Internet access
31
bull alternative technologies used includendash circuit switchingndash packet switchingndash frame relayndash Asynchronous Transfer Mode (ATM)
32
Circuit Switching
bull uses a dedicated communications path established for duration of conversation
bull comprising a sequence of physical links
bull with a dedicated logical channel
bull eg telephone network
33
Packet Switching
bull data sent out of sequence
bull small chunks (packets) of data at a time
bull packets passed from node to node between source and destination
bull used for terminal to computer and computer to computer communications
34
Frame Relay
bull packet switching systems have large overheads to compensate for errors
bull modern systems are more reliable
bull errors can be caught in end system
bull Frame Relay provides higher speeds
bull with most error control overhead removed
35
Asynchronous Transfer Mode(ATM)
bull evolution of frame relay
bull fixed packet (called cell) length
bull with little overhead for error control
bull anything from 10Mbps to Gbps
bull constant data rate using packet switching technique with multiple virtual circuits
36
Figure 111 WANs a switched WAN and a point-to-point WAN
37
Figure 112 A heterogeneous network made of four WANs and two LANs
38
Categories of Networks(cont)
bull Metropolitan Area Networks
bull MAN towncity
bull High-speed backbone linking multiple LANrsquos DSL TV cables
39
1-3 THE INTERNET1-3 THE INTERNET
The The InternetInternet has revolutionized many aspects of our has revolutionized many aspects of our daily lives It has affected the way we do business as well as the daily lives It has affected the way we do business as well as the way we spend our leisure time The Internet is a way we spend our leisure time The Internet is a communication system that has brought a wealth of communication system that has brought a wealth of information to our fingertips and organized it for our use information to our fingertips and organized it for our use
A Brief History The Internet Today (ISPs)
Topics discussed in this sectionTopics discussed in this section
40
The Internet
bull Internet evolved from ARPANETndash first operational packet networkndash applied to tactical radio amp satellite nets alsondash had a need for interoperabilityndash lead to standardized TCPIP protocols
41
The Internet
bull Huge number of interconnected Networks (100000rsquos) private organized egrsquo government schools research facilities in many countries
bull Collection of LANrsquoS MANrsquoS and WANrsquos ndash 1048708 The internet protocol stack is the TCPIP ndash 1048708 End users use the internet via Internet Service providers
(ISPs) which are of the following hierarchies
42
Figure 113 Hierarchical organization of the Internet
43
Internet Elements
44
Internet Architecture
45
Example Configuration
46
1-4 PROTOCOLS AND STANDARDS1-4 PROTOCOLS AND STANDARDS
In this section we define two widely used terms In this section we define two widely used terms protocolsprotocols and and standardsstandards First we define protocol which is synonymous with First we define protocol which is synonymous with rule Then we discuss standards which are agreed-upon rulesrule Then we discuss standards which are agreed-upon rules
ProtocolsStandardsStandards OrganizationsInternet Standards
Topics discussed in this sectionTopics discussed in this section
47
What is a protocol
Communications between computers requires very specific unambiguous rules A protocol is a set of rules that governs how two or more communicating parties are to interactExamples
Internet Protocol (IP)Transmission Control Protocol (TCP)HyperText Transfer Protocol (HTTP)Simple Mail Transfer Protocol (SMTP)
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
13
Network Criteria
bull
1) Performance Transmission and response times - throughput and delay 2) Reliability How often the networks fail 3) Security Privacy and integrity of
communication Data recovery from breaches and data loss
14
Physical Structures
bull Types of connections
bull 1) Point to Point (P to P) Dedicated link to be utilized only by end devices
bull 2) Multipoint (Multidrop) Many end devices share the link capacity
15
Figure 13 Types of connections point-to-point and multipoint
16
Physical Topology
17
Figure 14 Categories of topology
18
Physical Topology
bull A) Mesh
bull Each device has dedicated point-to-point link to other devices Fully connected mesh will have n( n-1) 2 FD links ndash Where n = number of nodes
bull Advantages Fast communication Robust and Privacy (Security)
bull Disadvantages Cabling Space and cost
19
Figure 15 A fully connected mesh topology (five devices)
20
Physical Topology (cont)
bull B) Star
bull Devices are connected Point to Point to a central ldquoHubrdquo (Controller Exchanger)
bull Advantages Less cabling and HW ports two hops only
bull Disadvantage Not robust
21
Figure 16 A star topology connecting four stations
22
Figure 17 A bus topology connecting three stations
23
ndash C) Bus
bull Multipoint link as ldquobackbonerdquo for a network where devices have drop line to tap into the bus
Advantage Less Cabling bull Disadvantages Topology dependent limit
number of nodes on the bus due to signal power loss with distance not so robust
24
Figure 18 A ring topology connecting six stations
25
bull C) Ring Each device connects Point to Point with only two other devices in a left and right neighbors arrangement via a repeater
bull Advantages easy installation better fault isolation and robustness
bull Disadvantages N2 hops communication
26
Figure 19 A hybrid topology a star backbone with three bus networks
27
bull D) Hybrid bull Pizza ldquostarrdquo inside a ldquo ringrdquo
bull Pros Better robustness still low cost Delay is 1 hop (until the star is not with a ring cut max 2 bull Star of busses
28
Categories of Networks
bull Local Area Networks (LAN) Few Kilometers Connects devices (PCs printers servers) within the same room building company and campus
bull Topologies most used are bus ring and star
29
Figure 110 An isolated LAN connecting 12 computers to a hub in a closet
30
Categories of Networks(cont)
bull Wide Area Networks (WAN)
bull span a large geographical area about 100rsquos ndash 1000rsquos of Km
bull 1) Switched End users connected via a cloud of switches (subnet)
bull 2) Point-to Point Line leased from telephone company TV connecting users
to the ISP for Internet access
31
bull alternative technologies used includendash circuit switchingndash packet switchingndash frame relayndash Asynchronous Transfer Mode (ATM)
32
Circuit Switching
bull uses a dedicated communications path established for duration of conversation
bull comprising a sequence of physical links
bull with a dedicated logical channel
bull eg telephone network
33
Packet Switching
bull data sent out of sequence
bull small chunks (packets) of data at a time
bull packets passed from node to node between source and destination
bull used for terminal to computer and computer to computer communications
34
Frame Relay
bull packet switching systems have large overheads to compensate for errors
bull modern systems are more reliable
bull errors can be caught in end system
bull Frame Relay provides higher speeds
bull with most error control overhead removed
35
Asynchronous Transfer Mode(ATM)
bull evolution of frame relay
bull fixed packet (called cell) length
bull with little overhead for error control
bull anything from 10Mbps to Gbps
bull constant data rate using packet switching technique with multiple virtual circuits
36
Figure 111 WANs a switched WAN and a point-to-point WAN
37
Figure 112 A heterogeneous network made of four WANs and two LANs
38
Categories of Networks(cont)
bull Metropolitan Area Networks
bull MAN towncity
bull High-speed backbone linking multiple LANrsquos DSL TV cables
39
1-3 THE INTERNET1-3 THE INTERNET
The The InternetInternet has revolutionized many aspects of our has revolutionized many aspects of our daily lives It has affected the way we do business as well as the daily lives It has affected the way we do business as well as the way we spend our leisure time The Internet is a way we spend our leisure time The Internet is a communication system that has brought a wealth of communication system that has brought a wealth of information to our fingertips and organized it for our use information to our fingertips and organized it for our use
A Brief History The Internet Today (ISPs)
Topics discussed in this sectionTopics discussed in this section
40
The Internet
bull Internet evolved from ARPANETndash first operational packet networkndash applied to tactical radio amp satellite nets alsondash had a need for interoperabilityndash lead to standardized TCPIP protocols
41
The Internet
bull Huge number of interconnected Networks (100000rsquos) private organized egrsquo government schools research facilities in many countries
bull Collection of LANrsquoS MANrsquoS and WANrsquos ndash 1048708 The internet protocol stack is the TCPIP ndash 1048708 End users use the internet via Internet Service providers
(ISPs) which are of the following hierarchies
42
Figure 113 Hierarchical organization of the Internet
43
Internet Elements
44
Internet Architecture
45
Example Configuration
46
1-4 PROTOCOLS AND STANDARDS1-4 PROTOCOLS AND STANDARDS
In this section we define two widely used terms In this section we define two widely used terms protocolsprotocols and and standardsstandards First we define protocol which is synonymous with First we define protocol which is synonymous with rule Then we discuss standards which are agreed-upon rulesrule Then we discuss standards which are agreed-upon rules
ProtocolsStandardsStandards OrganizationsInternet Standards
Topics discussed in this sectionTopics discussed in this section
47
What is a protocol
Communications between computers requires very specific unambiguous rules A protocol is a set of rules that governs how two or more communicating parties are to interactExamples
Internet Protocol (IP)Transmission Control Protocol (TCP)HyperText Transfer Protocol (HTTP)Simple Mail Transfer Protocol (SMTP)
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
14
Physical Structures
bull Types of connections
bull 1) Point to Point (P to P) Dedicated link to be utilized only by end devices
bull 2) Multipoint (Multidrop) Many end devices share the link capacity
15
Figure 13 Types of connections point-to-point and multipoint
16
Physical Topology
17
Figure 14 Categories of topology
18
Physical Topology
bull A) Mesh
bull Each device has dedicated point-to-point link to other devices Fully connected mesh will have n( n-1) 2 FD links ndash Where n = number of nodes
bull Advantages Fast communication Robust and Privacy (Security)
bull Disadvantages Cabling Space and cost
19
Figure 15 A fully connected mesh topology (five devices)
20
Physical Topology (cont)
bull B) Star
bull Devices are connected Point to Point to a central ldquoHubrdquo (Controller Exchanger)
bull Advantages Less cabling and HW ports two hops only
bull Disadvantage Not robust
21
Figure 16 A star topology connecting four stations
22
Figure 17 A bus topology connecting three stations
23
ndash C) Bus
bull Multipoint link as ldquobackbonerdquo for a network where devices have drop line to tap into the bus
Advantage Less Cabling bull Disadvantages Topology dependent limit
number of nodes on the bus due to signal power loss with distance not so robust
24
Figure 18 A ring topology connecting six stations
25
bull C) Ring Each device connects Point to Point with only two other devices in a left and right neighbors arrangement via a repeater
bull Advantages easy installation better fault isolation and robustness
bull Disadvantages N2 hops communication
26
Figure 19 A hybrid topology a star backbone with three bus networks
27
bull D) Hybrid bull Pizza ldquostarrdquo inside a ldquo ringrdquo
bull Pros Better robustness still low cost Delay is 1 hop (until the star is not with a ring cut max 2 bull Star of busses
28
Categories of Networks
bull Local Area Networks (LAN) Few Kilometers Connects devices (PCs printers servers) within the same room building company and campus
bull Topologies most used are bus ring and star
29
Figure 110 An isolated LAN connecting 12 computers to a hub in a closet
30
Categories of Networks(cont)
bull Wide Area Networks (WAN)
bull span a large geographical area about 100rsquos ndash 1000rsquos of Km
bull 1) Switched End users connected via a cloud of switches (subnet)
bull 2) Point-to Point Line leased from telephone company TV connecting users
to the ISP for Internet access
31
bull alternative technologies used includendash circuit switchingndash packet switchingndash frame relayndash Asynchronous Transfer Mode (ATM)
32
Circuit Switching
bull uses a dedicated communications path established for duration of conversation
bull comprising a sequence of physical links
bull with a dedicated logical channel
bull eg telephone network
33
Packet Switching
bull data sent out of sequence
bull small chunks (packets) of data at a time
bull packets passed from node to node between source and destination
bull used for terminal to computer and computer to computer communications
34
Frame Relay
bull packet switching systems have large overheads to compensate for errors
bull modern systems are more reliable
bull errors can be caught in end system
bull Frame Relay provides higher speeds
bull with most error control overhead removed
35
Asynchronous Transfer Mode(ATM)
bull evolution of frame relay
bull fixed packet (called cell) length
bull with little overhead for error control
bull anything from 10Mbps to Gbps
bull constant data rate using packet switching technique with multiple virtual circuits
36
Figure 111 WANs a switched WAN and a point-to-point WAN
37
Figure 112 A heterogeneous network made of four WANs and two LANs
38
Categories of Networks(cont)
bull Metropolitan Area Networks
bull MAN towncity
bull High-speed backbone linking multiple LANrsquos DSL TV cables
39
1-3 THE INTERNET1-3 THE INTERNET
The The InternetInternet has revolutionized many aspects of our has revolutionized many aspects of our daily lives It has affected the way we do business as well as the daily lives It has affected the way we do business as well as the way we spend our leisure time The Internet is a way we spend our leisure time The Internet is a communication system that has brought a wealth of communication system that has brought a wealth of information to our fingertips and organized it for our use information to our fingertips and organized it for our use
A Brief History The Internet Today (ISPs)
Topics discussed in this sectionTopics discussed in this section
40
The Internet
bull Internet evolved from ARPANETndash first operational packet networkndash applied to tactical radio amp satellite nets alsondash had a need for interoperabilityndash lead to standardized TCPIP protocols
41
The Internet
bull Huge number of interconnected Networks (100000rsquos) private organized egrsquo government schools research facilities in many countries
bull Collection of LANrsquoS MANrsquoS and WANrsquos ndash 1048708 The internet protocol stack is the TCPIP ndash 1048708 End users use the internet via Internet Service providers
(ISPs) which are of the following hierarchies
42
Figure 113 Hierarchical organization of the Internet
43
Internet Elements
44
Internet Architecture
45
Example Configuration
46
1-4 PROTOCOLS AND STANDARDS1-4 PROTOCOLS AND STANDARDS
In this section we define two widely used terms In this section we define two widely used terms protocolsprotocols and and standardsstandards First we define protocol which is synonymous with First we define protocol which is synonymous with rule Then we discuss standards which are agreed-upon rulesrule Then we discuss standards which are agreed-upon rules
ProtocolsStandardsStandards OrganizationsInternet Standards
Topics discussed in this sectionTopics discussed in this section
47
What is a protocol
Communications between computers requires very specific unambiguous rules A protocol is a set of rules that governs how two or more communicating parties are to interactExamples
Internet Protocol (IP)Transmission Control Protocol (TCP)HyperText Transfer Protocol (HTTP)Simple Mail Transfer Protocol (SMTP)
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
15
Figure 13 Types of connections point-to-point and multipoint
16
Physical Topology
17
Figure 14 Categories of topology
18
Physical Topology
bull A) Mesh
bull Each device has dedicated point-to-point link to other devices Fully connected mesh will have n( n-1) 2 FD links ndash Where n = number of nodes
bull Advantages Fast communication Robust and Privacy (Security)
bull Disadvantages Cabling Space and cost
19
Figure 15 A fully connected mesh topology (five devices)
20
Physical Topology (cont)
bull B) Star
bull Devices are connected Point to Point to a central ldquoHubrdquo (Controller Exchanger)
bull Advantages Less cabling and HW ports two hops only
bull Disadvantage Not robust
21
Figure 16 A star topology connecting four stations
22
Figure 17 A bus topology connecting three stations
23
ndash C) Bus
bull Multipoint link as ldquobackbonerdquo for a network where devices have drop line to tap into the bus
Advantage Less Cabling bull Disadvantages Topology dependent limit
number of nodes on the bus due to signal power loss with distance not so robust
24
Figure 18 A ring topology connecting six stations
25
bull C) Ring Each device connects Point to Point with only two other devices in a left and right neighbors arrangement via a repeater
bull Advantages easy installation better fault isolation and robustness
bull Disadvantages N2 hops communication
26
Figure 19 A hybrid topology a star backbone with three bus networks
27
bull D) Hybrid bull Pizza ldquostarrdquo inside a ldquo ringrdquo
bull Pros Better robustness still low cost Delay is 1 hop (until the star is not with a ring cut max 2 bull Star of busses
28
Categories of Networks
bull Local Area Networks (LAN) Few Kilometers Connects devices (PCs printers servers) within the same room building company and campus
bull Topologies most used are bus ring and star
29
Figure 110 An isolated LAN connecting 12 computers to a hub in a closet
30
Categories of Networks(cont)
bull Wide Area Networks (WAN)
bull span a large geographical area about 100rsquos ndash 1000rsquos of Km
bull 1) Switched End users connected via a cloud of switches (subnet)
bull 2) Point-to Point Line leased from telephone company TV connecting users
to the ISP for Internet access
31
bull alternative technologies used includendash circuit switchingndash packet switchingndash frame relayndash Asynchronous Transfer Mode (ATM)
32
Circuit Switching
bull uses a dedicated communications path established for duration of conversation
bull comprising a sequence of physical links
bull with a dedicated logical channel
bull eg telephone network
33
Packet Switching
bull data sent out of sequence
bull small chunks (packets) of data at a time
bull packets passed from node to node between source and destination
bull used for terminal to computer and computer to computer communications
34
Frame Relay
bull packet switching systems have large overheads to compensate for errors
bull modern systems are more reliable
bull errors can be caught in end system
bull Frame Relay provides higher speeds
bull with most error control overhead removed
35
Asynchronous Transfer Mode(ATM)
bull evolution of frame relay
bull fixed packet (called cell) length
bull with little overhead for error control
bull anything from 10Mbps to Gbps
bull constant data rate using packet switching technique with multiple virtual circuits
36
Figure 111 WANs a switched WAN and a point-to-point WAN
37
Figure 112 A heterogeneous network made of four WANs and two LANs
38
Categories of Networks(cont)
bull Metropolitan Area Networks
bull MAN towncity
bull High-speed backbone linking multiple LANrsquos DSL TV cables
39
1-3 THE INTERNET1-3 THE INTERNET
The The InternetInternet has revolutionized many aspects of our has revolutionized many aspects of our daily lives It has affected the way we do business as well as the daily lives It has affected the way we do business as well as the way we spend our leisure time The Internet is a way we spend our leisure time The Internet is a communication system that has brought a wealth of communication system that has brought a wealth of information to our fingertips and organized it for our use information to our fingertips and organized it for our use
A Brief History The Internet Today (ISPs)
Topics discussed in this sectionTopics discussed in this section
40
The Internet
bull Internet evolved from ARPANETndash first operational packet networkndash applied to tactical radio amp satellite nets alsondash had a need for interoperabilityndash lead to standardized TCPIP protocols
41
The Internet
bull Huge number of interconnected Networks (100000rsquos) private organized egrsquo government schools research facilities in many countries
bull Collection of LANrsquoS MANrsquoS and WANrsquos ndash 1048708 The internet protocol stack is the TCPIP ndash 1048708 End users use the internet via Internet Service providers
(ISPs) which are of the following hierarchies
42
Figure 113 Hierarchical organization of the Internet
43
Internet Elements
44
Internet Architecture
45
Example Configuration
46
1-4 PROTOCOLS AND STANDARDS1-4 PROTOCOLS AND STANDARDS
In this section we define two widely used terms In this section we define two widely used terms protocolsprotocols and and standardsstandards First we define protocol which is synonymous with First we define protocol which is synonymous with rule Then we discuss standards which are agreed-upon rulesrule Then we discuss standards which are agreed-upon rules
ProtocolsStandardsStandards OrganizationsInternet Standards
Topics discussed in this sectionTopics discussed in this section
47
What is a protocol
Communications between computers requires very specific unambiguous rules A protocol is a set of rules that governs how two or more communicating parties are to interactExamples
Internet Protocol (IP)Transmission Control Protocol (TCP)HyperText Transfer Protocol (HTTP)Simple Mail Transfer Protocol (SMTP)
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
16
Physical Topology
17
Figure 14 Categories of topology
18
Physical Topology
bull A) Mesh
bull Each device has dedicated point-to-point link to other devices Fully connected mesh will have n( n-1) 2 FD links ndash Where n = number of nodes
bull Advantages Fast communication Robust and Privacy (Security)
bull Disadvantages Cabling Space and cost
19
Figure 15 A fully connected mesh topology (five devices)
20
Physical Topology (cont)
bull B) Star
bull Devices are connected Point to Point to a central ldquoHubrdquo (Controller Exchanger)
bull Advantages Less cabling and HW ports two hops only
bull Disadvantage Not robust
21
Figure 16 A star topology connecting four stations
22
Figure 17 A bus topology connecting three stations
23
ndash C) Bus
bull Multipoint link as ldquobackbonerdquo for a network where devices have drop line to tap into the bus
Advantage Less Cabling bull Disadvantages Topology dependent limit
number of nodes on the bus due to signal power loss with distance not so robust
24
Figure 18 A ring topology connecting six stations
25
bull C) Ring Each device connects Point to Point with only two other devices in a left and right neighbors arrangement via a repeater
bull Advantages easy installation better fault isolation and robustness
bull Disadvantages N2 hops communication
26
Figure 19 A hybrid topology a star backbone with three bus networks
27
bull D) Hybrid bull Pizza ldquostarrdquo inside a ldquo ringrdquo
bull Pros Better robustness still low cost Delay is 1 hop (until the star is not with a ring cut max 2 bull Star of busses
28
Categories of Networks
bull Local Area Networks (LAN) Few Kilometers Connects devices (PCs printers servers) within the same room building company and campus
bull Topologies most used are bus ring and star
29
Figure 110 An isolated LAN connecting 12 computers to a hub in a closet
30
Categories of Networks(cont)
bull Wide Area Networks (WAN)
bull span a large geographical area about 100rsquos ndash 1000rsquos of Km
bull 1) Switched End users connected via a cloud of switches (subnet)
bull 2) Point-to Point Line leased from telephone company TV connecting users
to the ISP for Internet access
31
bull alternative technologies used includendash circuit switchingndash packet switchingndash frame relayndash Asynchronous Transfer Mode (ATM)
32
Circuit Switching
bull uses a dedicated communications path established for duration of conversation
bull comprising a sequence of physical links
bull with a dedicated logical channel
bull eg telephone network
33
Packet Switching
bull data sent out of sequence
bull small chunks (packets) of data at a time
bull packets passed from node to node between source and destination
bull used for terminal to computer and computer to computer communications
34
Frame Relay
bull packet switching systems have large overheads to compensate for errors
bull modern systems are more reliable
bull errors can be caught in end system
bull Frame Relay provides higher speeds
bull with most error control overhead removed
35
Asynchronous Transfer Mode(ATM)
bull evolution of frame relay
bull fixed packet (called cell) length
bull with little overhead for error control
bull anything from 10Mbps to Gbps
bull constant data rate using packet switching technique with multiple virtual circuits
36
Figure 111 WANs a switched WAN and a point-to-point WAN
37
Figure 112 A heterogeneous network made of four WANs and two LANs
38
Categories of Networks(cont)
bull Metropolitan Area Networks
bull MAN towncity
bull High-speed backbone linking multiple LANrsquos DSL TV cables
39
1-3 THE INTERNET1-3 THE INTERNET
The The InternetInternet has revolutionized many aspects of our has revolutionized many aspects of our daily lives It has affected the way we do business as well as the daily lives It has affected the way we do business as well as the way we spend our leisure time The Internet is a way we spend our leisure time The Internet is a communication system that has brought a wealth of communication system that has brought a wealth of information to our fingertips and organized it for our use information to our fingertips and organized it for our use
A Brief History The Internet Today (ISPs)
Topics discussed in this sectionTopics discussed in this section
40
The Internet
bull Internet evolved from ARPANETndash first operational packet networkndash applied to tactical radio amp satellite nets alsondash had a need for interoperabilityndash lead to standardized TCPIP protocols
41
The Internet
bull Huge number of interconnected Networks (100000rsquos) private organized egrsquo government schools research facilities in many countries
bull Collection of LANrsquoS MANrsquoS and WANrsquos ndash 1048708 The internet protocol stack is the TCPIP ndash 1048708 End users use the internet via Internet Service providers
(ISPs) which are of the following hierarchies
42
Figure 113 Hierarchical organization of the Internet
43
Internet Elements
44
Internet Architecture
45
Example Configuration
46
1-4 PROTOCOLS AND STANDARDS1-4 PROTOCOLS AND STANDARDS
In this section we define two widely used terms In this section we define two widely used terms protocolsprotocols and and standardsstandards First we define protocol which is synonymous with First we define protocol which is synonymous with rule Then we discuss standards which are agreed-upon rulesrule Then we discuss standards which are agreed-upon rules
ProtocolsStandardsStandards OrganizationsInternet Standards
Topics discussed in this sectionTopics discussed in this section
47
What is a protocol
Communications between computers requires very specific unambiguous rules A protocol is a set of rules that governs how two or more communicating parties are to interactExamples
Internet Protocol (IP)Transmission Control Protocol (TCP)HyperText Transfer Protocol (HTTP)Simple Mail Transfer Protocol (SMTP)
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
17
Figure 14 Categories of topology
18
Physical Topology
bull A) Mesh
bull Each device has dedicated point-to-point link to other devices Fully connected mesh will have n( n-1) 2 FD links ndash Where n = number of nodes
bull Advantages Fast communication Robust and Privacy (Security)
bull Disadvantages Cabling Space and cost
19
Figure 15 A fully connected mesh topology (five devices)
20
Physical Topology (cont)
bull B) Star
bull Devices are connected Point to Point to a central ldquoHubrdquo (Controller Exchanger)
bull Advantages Less cabling and HW ports two hops only
bull Disadvantage Not robust
21
Figure 16 A star topology connecting four stations
22
Figure 17 A bus topology connecting three stations
23
ndash C) Bus
bull Multipoint link as ldquobackbonerdquo for a network where devices have drop line to tap into the bus
Advantage Less Cabling bull Disadvantages Topology dependent limit
number of nodes on the bus due to signal power loss with distance not so robust
24
Figure 18 A ring topology connecting six stations
25
bull C) Ring Each device connects Point to Point with only two other devices in a left and right neighbors arrangement via a repeater
bull Advantages easy installation better fault isolation and robustness
bull Disadvantages N2 hops communication
26
Figure 19 A hybrid topology a star backbone with three bus networks
27
bull D) Hybrid bull Pizza ldquostarrdquo inside a ldquo ringrdquo
bull Pros Better robustness still low cost Delay is 1 hop (until the star is not with a ring cut max 2 bull Star of busses
28
Categories of Networks
bull Local Area Networks (LAN) Few Kilometers Connects devices (PCs printers servers) within the same room building company and campus
bull Topologies most used are bus ring and star
29
Figure 110 An isolated LAN connecting 12 computers to a hub in a closet
30
Categories of Networks(cont)
bull Wide Area Networks (WAN)
bull span a large geographical area about 100rsquos ndash 1000rsquos of Km
bull 1) Switched End users connected via a cloud of switches (subnet)
bull 2) Point-to Point Line leased from telephone company TV connecting users
to the ISP for Internet access
31
bull alternative technologies used includendash circuit switchingndash packet switchingndash frame relayndash Asynchronous Transfer Mode (ATM)
32
Circuit Switching
bull uses a dedicated communications path established for duration of conversation
bull comprising a sequence of physical links
bull with a dedicated logical channel
bull eg telephone network
33
Packet Switching
bull data sent out of sequence
bull small chunks (packets) of data at a time
bull packets passed from node to node between source and destination
bull used for terminal to computer and computer to computer communications
34
Frame Relay
bull packet switching systems have large overheads to compensate for errors
bull modern systems are more reliable
bull errors can be caught in end system
bull Frame Relay provides higher speeds
bull with most error control overhead removed
35
Asynchronous Transfer Mode(ATM)
bull evolution of frame relay
bull fixed packet (called cell) length
bull with little overhead for error control
bull anything from 10Mbps to Gbps
bull constant data rate using packet switching technique with multiple virtual circuits
36
Figure 111 WANs a switched WAN and a point-to-point WAN
37
Figure 112 A heterogeneous network made of four WANs and two LANs
38
Categories of Networks(cont)
bull Metropolitan Area Networks
bull MAN towncity
bull High-speed backbone linking multiple LANrsquos DSL TV cables
39
1-3 THE INTERNET1-3 THE INTERNET
The The InternetInternet has revolutionized many aspects of our has revolutionized many aspects of our daily lives It has affected the way we do business as well as the daily lives It has affected the way we do business as well as the way we spend our leisure time The Internet is a way we spend our leisure time The Internet is a communication system that has brought a wealth of communication system that has brought a wealth of information to our fingertips and organized it for our use information to our fingertips and organized it for our use
A Brief History The Internet Today (ISPs)
Topics discussed in this sectionTopics discussed in this section
40
The Internet
bull Internet evolved from ARPANETndash first operational packet networkndash applied to tactical radio amp satellite nets alsondash had a need for interoperabilityndash lead to standardized TCPIP protocols
41
The Internet
bull Huge number of interconnected Networks (100000rsquos) private organized egrsquo government schools research facilities in many countries
bull Collection of LANrsquoS MANrsquoS and WANrsquos ndash 1048708 The internet protocol stack is the TCPIP ndash 1048708 End users use the internet via Internet Service providers
(ISPs) which are of the following hierarchies
42
Figure 113 Hierarchical organization of the Internet
43
Internet Elements
44
Internet Architecture
45
Example Configuration
46
1-4 PROTOCOLS AND STANDARDS1-4 PROTOCOLS AND STANDARDS
In this section we define two widely used terms In this section we define two widely used terms protocolsprotocols and and standardsstandards First we define protocol which is synonymous with First we define protocol which is synonymous with rule Then we discuss standards which are agreed-upon rulesrule Then we discuss standards which are agreed-upon rules
ProtocolsStandardsStandards OrganizationsInternet Standards
Topics discussed in this sectionTopics discussed in this section
47
What is a protocol
Communications between computers requires very specific unambiguous rules A protocol is a set of rules that governs how two or more communicating parties are to interactExamples
Internet Protocol (IP)Transmission Control Protocol (TCP)HyperText Transfer Protocol (HTTP)Simple Mail Transfer Protocol (SMTP)
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
18
Physical Topology
bull A) Mesh
bull Each device has dedicated point-to-point link to other devices Fully connected mesh will have n( n-1) 2 FD links ndash Where n = number of nodes
bull Advantages Fast communication Robust and Privacy (Security)
bull Disadvantages Cabling Space and cost
19
Figure 15 A fully connected mesh topology (five devices)
20
Physical Topology (cont)
bull B) Star
bull Devices are connected Point to Point to a central ldquoHubrdquo (Controller Exchanger)
bull Advantages Less cabling and HW ports two hops only
bull Disadvantage Not robust
21
Figure 16 A star topology connecting four stations
22
Figure 17 A bus topology connecting three stations
23
ndash C) Bus
bull Multipoint link as ldquobackbonerdquo for a network where devices have drop line to tap into the bus
Advantage Less Cabling bull Disadvantages Topology dependent limit
number of nodes on the bus due to signal power loss with distance not so robust
24
Figure 18 A ring topology connecting six stations
25
bull C) Ring Each device connects Point to Point with only two other devices in a left and right neighbors arrangement via a repeater
bull Advantages easy installation better fault isolation and robustness
bull Disadvantages N2 hops communication
26
Figure 19 A hybrid topology a star backbone with three bus networks
27
bull D) Hybrid bull Pizza ldquostarrdquo inside a ldquo ringrdquo
bull Pros Better robustness still low cost Delay is 1 hop (until the star is not with a ring cut max 2 bull Star of busses
28
Categories of Networks
bull Local Area Networks (LAN) Few Kilometers Connects devices (PCs printers servers) within the same room building company and campus
bull Topologies most used are bus ring and star
29
Figure 110 An isolated LAN connecting 12 computers to a hub in a closet
30
Categories of Networks(cont)
bull Wide Area Networks (WAN)
bull span a large geographical area about 100rsquos ndash 1000rsquos of Km
bull 1) Switched End users connected via a cloud of switches (subnet)
bull 2) Point-to Point Line leased from telephone company TV connecting users
to the ISP for Internet access
31
bull alternative technologies used includendash circuit switchingndash packet switchingndash frame relayndash Asynchronous Transfer Mode (ATM)
32
Circuit Switching
bull uses a dedicated communications path established for duration of conversation
bull comprising a sequence of physical links
bull with a dedicated logical channel
bull eg telephone network
33
Packet Switching
bull data sent out of sequence
bull small chunks (packets) of data at a time
bull packets passed from node to node between source and destination
bull used for terminal to computer and computer to computer communications
34
Frame Relay
bull packet switching systems have large overheads to compensate for errors
bull modern systems are more reliable
bull errors can be caught in end system
bull Frame Relay provides higher speeds
bull with most error control overhead removed
35
Asynchronous Transfer Mode(ATM)
bull evolution of frame relay
bull fixed packet (called cell) length
bull with little overhead for error control
bull anything from 10Mbps to Gbps
bull constant data rate using packet switching technique with multiple virtual circuits
36
Figure 111 WANs a switched WAN and a point-to-point WAN
37
Figure 112 A heterogeneous network made of four WANs and two LANs
38
Categories of Networks(cont)
bull Metropolitan Area Networks
bull MAN towncity
bull High-speed backbone linking multiple LANrsquos DSL TV cables
39
1-3 THE INTERNET1-3 THE INTERNET
The The InternetInternet has revolutionized many aspects of our has revolutionized many aspects of our daily lives It has affected the way we do business as well as the daily lives It has affected the way we do business as well as the way we spend our leisure time The Internet is a way we spend our leisure time The Internet is a communication system that has brought a wealth of communication system that has brought a wealth of information to our fingertips and organized it for our use information to our fingertips and organized it for our use
A Brief History The Internet Today (ISPs)
Topics discussed in this sectionTopics discussed in this section
40
The Internet
bull Internet evolved from ARPANETndash first operational packet networkndash applied to tactical radio amp satellite nets alsondash had a need for interoperabilityndash lead to standardized TCPIP protocols
41
The Internet
bull Huge number of interconnected Networks (100000rsquos) private organized egrsquo government schools research facilities in many countries
bull Collection of LANrsquoS MANrsquoS and WANrsquos ndash 1048708 The internet protocol stack is the TCPIP ndash 1048708 End users use the internet via Internet Service providers
(ISPs) which are of the following hierarchies
42
Figure 113 Hierarchical organization of the Internet
43
Internet Elements
44
Internet Architecture
45
Example Configuration
46
1-4 PROTOCOLS AND STANDARDS1-4 PROTOCOLS AND STANDARDS
In this section we define two widely used terms In this section we define two widely used terms protocolsprotocols and and standardsstandards First we define protocol which is synonymous with First we define protocol which is synonymous with rule Then we discuss standards which are agreed-upon rulesrule Then we discuss standards which are agreed-upon rules
ProtocolsStandardsStandards OrganizationsInternet Standards
Topics discussed in this sectionTopics discussed in this section
47
What is a protocol
Communications between computers requires very specific unambiguous rules A protocol is a set of rules that governs how two or more communicating parties are to interactExamples
Internet Protocol (IP)Transmission Control Protocol (TCP)HyperText Transfer Protocol (HTTP)Simple Mail Transfer Protocol (SMTP)
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
19
Figure 15 A fully connected mesh topology (five devices)
20
Physical Topology (cont)
bull B) Star
bull Devices are connected Point to Point to a central ldquoHubrdquo (Controller Exchanger)
bull Advantages Less cabling and HW ports two hops only
bull Disadvantage Not robust
21
Figure 16 A star topology connecting four stations
22
Figure 17 A bus topology connecting three stations
23
ndash C) Bus
bull Multipoint link as ldquobackbonerdquo for a network where devices have drop line to tap into the bus
Advantage Less Cabling bull Disadvantages Topology dependent limit
number of nodes on the bus due to signal power loss with distance not so robust
24
Figure 18 A ring topology connecting six stations
25
bull C) Ring Each device connects Point to Point with only two other devices in a left and right neighbors arrangement via a repeater
bull Advantages easy installation better fault isolation and robustness
bull Disadvantages N2 hops communication
26
Figure 19 A hybrid topology a star backbone with three bus networks
27
bull D) Hybrid bull Pizza ldquostarrdquo inside a ldquo ringrdquo
bull Pros Better robustness still low cost Delay is 1 hop (until the star is not with a ring cut max 2 bull Star of busses
28
Categories of Networks
bull Local Area Networks (LAN) Few Kilometers Connects devices (PCs printers servers) within the same room building company and campus
bull Topologies most used are bus ring and star
29
Figure 110 An isolated LAN connecting 12 computers to a hub in a closet
30
Categories of Networks(cont)
bull Wide Area Networks (WAN)
bull span a large geographical area about 100rsquos ndash 1000rsquos of Km
bull 1) Switched End users connected via a cloud of switches (subnet)
bull 2) Point-to Point Line leased from telephone company TV connecting users
to the ISP for Internet access
31
bull alternative technologies used includendash circuit switchingndash packet switchingndash frame relayndash Asynchronous Transfer Mode (ATM)
32
Circuit Switching
bull uses a dedicated communications path established for duration of conversation
bull comprising a sequence of physical links
bull with a dedicated logical channel
bull eg telephone network
33
Packet Switching
bull data sent out of sequence
bull small chunks (packets) of data at a time
bull packets passed from node to node between source and destination
bull used for terminal to computer and computer to computer communications
34
Frame Relay
bull packet switching systems have large overheads to compensate for errors
bull modern systems are more reliable
bull errors can be caught in end system
bull Frame Relay provides higher speeds
bull with most error control overhead removed
35
Asynchronous Transfer Mode(ATM)
bull evolution of frame relay
bull fixed packet (called cell) length
bull with little overhead for error control
bull anything from 10Mbps to Gbps
bull constant data rate using packet switching technique with multiple virtual circuits
36
Figure 111 WANs a switched WAN and a point-to-point WAN
37
Figure 112 A heterogeneous network made of four WANs and two LANs
38
Categories of Networks(cont)
bull Metropolitan Area Networks
bull MAN towncity
bull High-speed backbone linking multiple LANrsquos DSL TV cables
39
1-3 THE INTERNET1-3 THE INTERNET
The The InternetInternet has revolutionized many aspects of our has revolutionized many aspects of our daily lives It has affected the way we do business as well as the daily lives It has affected the way we do business as well as the way we spend our leisure time The Internet is a way we spend our leisure time The Internet is a communication system that has brought a wealth of communication system that has brought a wealth of information to our fingertips and organized it for our use information to our fingertips and organized it for our use
A Brief History The Internet Today (ISPs)
Topics discussed in this sectionTopics discussed in this section
40
The Internet
bull Internet evolved from ARPANETndash first operational packet networkndash applied to tactical radio amp satellite nets alsondash had a need for interoperabilityndash lead to standardized TCPIP protocols
41
The Internet
bull Huge number of interconnected Networks (100000rsquos) private organized egrsquo government schools research facilities in many countries
bull Collection of LANrsquoS MANrsquoS and WANrsquos ndash 1048708 The internet protocol stack is the TCPIP ndash 1048708 End users use the internet via Internet Service providers
(ISPs) which are of the following hierarchies
42
Figure 113 Hierarchical organization of the Internet
43
Internet Elements
44
Internet Architecture
45
Example Configuration
46
1-4 PROTOCOLS AND STANDARDS1-4 PROTOCOLS AND STANDARDS
In this section we define two widely used terms In this section we define two widely used terms protocolsprotocols and and standardsstandards First we define protocol which is synonymous with First we define protocol which is synonymous with rule Then we discuss standards which are agreed-upon rulesrule Then we discuss standards which are agreed-upon rules
ProtocolsStandardsStandards OrganizationsInternet Standards
Topics discussed in this sectionTopics discussed in this section
47
What is a protocol
Communications between computers requires very specific unambiguous rules A protocol is a set of rules that governs how two or more communicating parties are to interactExamples
Internet Protocol (IP)Transmission Control Protocol (TCP)HyperText Transfer Protocol (HTTP)Simple Mail Transfer Protocol (SMTP)
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
20
Physical Topology (cont)
bull B) Star
bull Devices are connected Point to Point to a central ldquoHubrdquo (Controller Exchanger)
bull Advantages Less cabling and HW ports two hops only
bull Disadvantage Not robust
21
Figure 16 A star topology connecting four stations
22
Figure 17 A bus topology connecting three stations
23
ndash C) Bus
bull Multipoint link as ldquobackbonerdquo for a network where devices have drop line to tap into the bus
Advantage Less Cabling bull Disadvantages Topology dependent limit
number of nodes on the bus due to signal power loss with distance not so robust
24
Figure 18 A ring topology connecting six stations
25
bull C) Ring Each device connects Point to Point with only two other devices in a left and right neighbors arrangement via a repeater
bull Advantages easy installation better fault isolation and robustness
bull Disadvantages N2 hops communication
26
Figure 19 A hybrid topology a star backbone with three bus networks
27
bull D) Hybrid bull Pizza ldquostarrdquo inside a ldquo ringrdquo
bull Pros Better robustness still low cost Delay is 1 hop (until the star is not with a ring cut max 2 bull Star of busses
28
Categories of Networks
bull Local Area Networks (LAN) Few Kilometers Connects devices (PCs printers servers) within the same room building company and campus
bull Topologies most used are bus ring and star
29
Figure 110 An isolated LAN connecting 12 computers to a hub in a closet
30
Categories of Networks(cont)
bull Wide Area Networks (WAN)
bull span a large geographical area about 100rsquos ndash 1000rsquos of Km
bull 1) Switched End users connected via a cloud of switches (subnet)
bull 2) Point-to Point Line leased from telephone company TV connecting users
to the ISP for Internet access
31
bull alternative technologies used includendash circuit switchingndash packet switchingndash frame relayndash Asynchronous Transfer Mode (ATM)
32
Circuit Switching
bull uses a dedicated communications path established for duration of conversation
bull comprising a sequence of physical links
bull with a dedicated logical channel
bull eg telephone network
33
Packet Switching
bull data sent out of sequence
bull small chunks (packets) of data at a time
bull packets passed from node to node between source and destination
bull used for terminal to computer and computer to computer communications
34
Frame Relay
bull packet switching systems have large overheads to compensate for errors
bull modern systems are more reliable
bull errors can be caught in end system
bull Frame Relay provides higher speeds
bull with most error control overhead removed
35
Asynchronous Transfer Mode(ATM)
bull evolution of frame relay
bull fixed packet (called cell) length
bull with little overhead for error control
bull anything from 10Mbps to Gbps
bull constant data rate using packet switching technique with multiple virtual circuits
36
Figure 111 WANs a switched WAN and a point-to-point WAN
37
Figure 112 A heterogeneous network made of four WANs and two LANs
38
Categories of Networks(cont)
bull Metropolitan Area Networks
bull MAN towncity
bull High-speed backbone linking multiple LANrsquos DSL TV cables
39
1-3 THE INTERNET1-3 THE INTERNET
The The InternetInternet has revolutionized many aspects of our has revolutionized many aspects of our daily lives It has affected the way we do business as well as the daily lives It has affected the way we do business as well as the way we spend our leisure time The Internet is a way we spend our leisure time The Internet is a communication system that has brought a wealth of communication system that has brought a wealth of information to our fingertips and organized it for our use information to our fingertips and organized it for our use
A Brief History The Internet Today (ISPs)
Topics discussed in this sectionTopics discussed in this section
40
The Internet
bull Internet evolved from ARPANETndash first operational packet networkndash applied to tactical radio amp satellite nets alsondash had a need for interoperabilityndash lead to standardized TCPIP protocols
41
The Internet
bull Huge number of interconnected Networks (100000rsquos) private organized egrsquo government schools research facilities in many countries
bull Collection of LANrsquoS MANrsquoS and WANrsquos ndash 1048708 The internet protocol stack is the TCPIP ndash 1048708 End users use the internet via Internet Service providers
(ISPs) which are of the following hierarchies
42
Figure 113 Hierarchical organization of the Internet
43
Internet Elements
44
Internet Architecture
45
Example Configuration
46
1-4 PROTOCOLS AND STANDARDS1-4 PROTOCOLS AND STANDARDS
In this section we define two widely used terms In this section we define two widely used terms protocolsprotocols and and standardsstandards First we define protocol which is synonymous with First we define protocol which is synonymous with rule Then we discuss standards which are agreed-upon rulesrule Then we discuss standards which are agreed-upon rules
ProtocolsStandardsStandards OrganizationsInternet Standards
Topics discussed in this sectionTopics discussed in this section
47
What is a protocol
Communications between computers requires very specific unambiguous rules A protocol is a set of rules that governs how two or more communicating parties are to interactExamples
Internet Protocol (IP)Transmission Control Protocol (TCP)HyperText Transfer Protocol (HTTP)Simple Mail Transfer Protocol (SMTP)
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
21
Figure 16 A star topology connecting four stations
22
Figure 17 A bus topology connecting three stations
23
ndash C) Bus
bull Multipoint link as ldquobackbonerdquo for a network where devices have drop line to tap into the bus
Advantage Less Cabling bull Disadvantages Topology dependent limit
number of nodes on the bus due to signal power loss with distance not so robust
24
Figure 18 A ring topology connecting six stations
25
bull C) Ring Each device connects Point to Point with only two other devices in a left and right neighbors arrangement via a repeater
bull Advantages easy installation better fault isolation and robustness
bull Disadvantages N2 hops communication
26
Figure 19 A hybrid topology a star backbone with three bus networks
27
bull D) Hybrid bull Pizza ldquostarrdquo inside a ldquo ringrdquo
bull Pros Better robustness still low cost Delay is 1 hop (until the star is not with a ring cut max 2 bull Star of busses
28
Categories of Networks
bull Local Area Networks (LAN) Few Kilometers Connects devices (PCs printers servers) within the same room building company and campus
bull Topologies most used are bus ring and star
29
Figure 110 An isolated LAN connecting 12 computers to a hub in a closet
30
Categories of Networks(cont)
bull Wide Area Networks (WAN)
bull span a large geographical area about 100rsquos ndash 1000rsquos of Km
bull 1) Switched End users connected via a cloud of switches (subnet)
bull 2) Point-to Point Line leased from telephone company TV connecting users
to the ISP for Internet access
31
bull alternative technologies used includendash circuit switchingndash packet switchingndash frame relayndash Asynchronous Transfer Mode (ATM)
32
Circuit Switching
bull uses a dedicated communications path established for duration of conversation
bull comprising a sequence of physical links
bull with a dedicated logical channel
bull eg telephone network
33
Packet Switching
bull data sent out of sequence
bull small chunks (packets) of data at a time
bull packets passed from node to node between source and destination
bull used for terminal to computer and computer to computer communications
34
Frame Relay
bull packet switching systems have large overheads to compensate for errors
bull modern systems are more reliable
bull errors can be caught in end system
bull Frame Relay provides higher speeds
bull with most error control overhead removed
35
Asynchronous Transfer Mode(ATM)
bull evolution of frame relay
bull fixed packet (called cell) length
bull with little overhead for error control
bull anything from 10Mbps to Gbps
bull constant data rate using packet switching technique with multiple virtual circuits
36
Figure 111 WANs a switched WAN and a point-to-point WAN
37
Figure 112 A heterogeneous network made of four WANs and two LANs
38
Categories of Networks(cont)
bull Metropolitan Area Networks
bull MAN towncity
bull High-speed backbone linking multiple LANrsquos DSL TV cables
39
1-3 THE INTERNET1-3 THE INTERNET
The The InternetInternet has revolutionized many aspects of our has revolutionized many aspects of our daily lives It has affected the way we do business as well as the daily lives It has affected the way we do business as well as the way we spend our leisure time The Internet is a way we spend our leisure time The Internet is a communication system that has brought a wealth of communication system that has brought a wealth of information to our fingertips and organized it for our use information to our fingertips and organized it for our use
A Brief History The Internet Today (ISPs)
Topics discussed in this sectionTopics discussed in this section
40
The Internet
bull Internet evolved from ARPANETndash first operational packet networkndash applied to tactical radio amp satellite nets alsondash had a need for interoperabilityndash lead to standardized TCPIP protocols
41
The Internet
bull Huge number of interconnected Networks (100000rsquos) private organized egrsquo government schools research facilities in many countries
bull Collection of LANrsquoS MANrsquoS and WANrsquos ndash 1048708 The internet protocol stack is the TCPIP ndash 1048708 End users use the internet via Internet Service providers
(ISPs) which are of the following hierarchies
42
Figure 113 Hierarchical organization of the Internet
43
Internet Elements
44
Internet Architecture
45
Example Configuration
46
1-4 PROTOCOLS AND STANDARDS1-4 PROTOCOLS AND STANDARDS
In this section we define two widely used terms In this section we define two widely used terms protocolsprotocols and and standardsstandards First we define protocol which is synonymous with First we define protocol which is synonymous with rule Then we discuss standards which are agreed-upon rulesrule Then we discuss standards which are agreed-upon rules
ProtocolsStandardsStandards OrganizationsInternet Standards
Topics discussed in this sectionTopics discussed in this section
47
What is a protocol
Communications between computers requires very specific unambiguous rules A protocol is a set of rules that governs how two or more communicating parties are to interactExamples
Internet Protocol (IP)Transmission Control Protocol (TCP)HyperText Transfer Protocol (HTTP)Simple Mail Transfer Protocol (SMTP)
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
22
Figure 17 A bus topology connecting three stations
23
ndash C) Bus
bull Multipoint link as ldquobackbonerdquo for a network where devices have drop line to tap into the bus
Advantage Less Cabling bull Disadvantages Topology dependent limit
number of nodes on the bus due to signal power loss with distance not so robust
24
Figure 18 A ring topology connecting six stations
25
bull C) Ring Each device connects Point to Point with only two other devices in a left and right neighbors arrangement via a repeater
bull Advantages easy installation better fault isolation and robustness
bull Disadvantages N2 hops communication
26
Figure 19 A hybrid topology a star backbone with three bus networks
27
bull D) Hybrid bull Pizza ldquostarrdquo inside a ldquo ringrdquo
bull Pros Better robustness still low cost Delay is 1 hop (until the star is not with a ring cut max 2 bull Star of busses
28
Categories of Networks
bull Local Area Networks (LAN) Few Kilometers Connects devices (PCs printers servers) within the same room building company and campus
bull Topologies most used are bus ring and star
29
Figure 110 An isolated LAN connecting 12 computers to a hub in a closet
30
Categories of Networks(cont)
bull Wide Area Networks (WAN)
bull span a large geographical area about 100rsquos ndash 1000rsquos of Km
bull 1) Switched End users connected via a cloud of switches (subnet)
bull 2) Point-to Point Line leased from telephone company TV connecting users
to the ISP for Internet access
31
bull alternative technologies used includendash circuit switchingndash packet switchingndash frame relayndash Asynchronous Transfer Mode (ATM)
32
Circuit Switching
bull uses a dedicated communications path established for duration of conversation
bull comprising a sequence of physical links
bull with a dedicated logical channel
bull eg telephone network
33
Packet Switching
bull data sent out of sequence
bull small chunks (packets) of data at a time
bull packets passed from node to node between source and destination
bull used for terminal to computer and computer to computer communications
34
Frame Relay
bull packet switching systems have large overheads to compensate for errors
bull modern systems are more reliable
bull errors can be caught in end system
bull Frame Relay provides higher speeds
bull with most error control overhead removed
35
Asynchronous Transfer Mode(ATM)
bull evolution of frame relay
bull fixed packet (called cell) length
bull with little overhead for error control
bull anything from 10Mbps to Gbps
bull constant data rate using packet switching technique with multiple virtual circuits
36
Figure 111 WANs a switched WAN and a point-to-point WAN
37
Figure 112 A heterogeneous network made of four WANs and two LANs
38
Categories of Networks(cont)
bull Metropolitan Area Networks
bull MAN towncity
bull High-speed backbone linking multiple LANrsquos DSL TV cables
39
1-3 THE INTERNET1-3 THE INTERNET
The The InternetInternet has revolutionized many aspects of our has revolutionized many aspects of our daily lives It has affected the way we do business as well as the daily lives It has affected the way we do business as well as the way we spend our leisure time The Internet is a way we spend our leisure time The Internet is a communication system that has brought a wealth of communication system that has brought a wealth of information to our fingertips and organized it for our use information to our fingertips and organized it for our use
A Brief History The Internet Today (ISPs)
Topics discussed in this sectionTopics discussed in this section
40
The Internet
bull Internet evolved from ARPANETndash first operational packet networkndash applied to tactical radio amp satellite nets alsondash had a need for interoperabilityndash lead to standardized TCPIP protocols
41
The Internet
bull Huge number of interconnected Networks (100000rsquos) private organized egrsquo government schools research facilities in many countries
bull Collection of LANrsquoS MANrsquoS and WANrsquos ndash 1048708 The internet protocol stack is the TCPIP ndash 1048708 End users use the internet via Internet Service providers
(ISPs) which are of the following hierarchies
42
Figure 113 Hierarchical organization of the Internet
43
Internet Elements
44
Internet Architecture
45
Example Configuration
46
1-4 PROTOCOLS AND STANDARDS1-4 PROTOCOLS AND STANDARDS
In this section we define two widely used terms In this section we define two widely used terms protocolsprotocols and and standardsstandards First we define protocol which is synonymous with First we define protocol which is synonymous with rule Then we discuss standards which are agreed-upon rulesrule Then we discuss standards which are agreed-upon rules
ProtocolsStandardsStandards OrganizationsInternet Standards
Topics discussed in this sectionTopics discussed in this section
47
What is a protocol
Communications between computers requires very specific unambiguous rules A protocol is a set of rules that governs how two or more communicating parties are to interactExamples
Internet Protocol (IP)Transmission Control Protocol (TCP)HyperText Transfer Protocol (HTTP)Simple Mail Transfer Protocol (SMTP)
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
23
ndash C) Bus
bull Multipoint link as ldquobackbonerdquo for a network where devices have drop line to tap into the bus
Advantage Less Cabling bull Disadvantages Topology dependent limit
number of nodes on the bus due to signal power loss with distance not so robust
24
Figure 18 A ring topology connecting six stations
25
bull C) Ring Each device connects Point to Point with only two other devices in a left and right neighbors arrangement via a repeater
bull Advantages easy installation better fault isolation and robustness
bull Disadvantages N2 hops communication
26
Figure 19 A hybrid topology a star backbone with three bus networks
27
bull D) Hybrid bull Pizza ldquostarrdquo inside a ldquo ringrdquo
bull Pros Better robustness still low cost Delay is 1 hop (until the star is not with a ring cut max 2 bull Star of busses
28
Categories of Networks
bull Local Area Networks (LAN) Few Kilometers Connects devices (PCs printers servers) within the same room building company and campus
bull Topologies most used are bus ring and star
29
Figure 110 An isolated LAN connecting 12 computers to a hub in a closet
30
Categories of Networks(cont)
bull Wide Area Networks (WAN)
bull span a large geographical area about 100rsquos ndash 1000rsquos of Km
bull 1) Switched End users connected via a cloud of switches (subnet)
bull 2) Point-to Point Line leased from telephone company TV connecting users
to the ISP for Internet access
31
bull alternative technologies used includendash circuit switchingndash packet switchingndash frame relayndash Asynchronous Transfer Mode (ATM)
32
Circuit Switching
bull uses a dedicated communications path established for duration of conversation
bull comprising a sequence of physical links
bull with a dedicated logical channel
bull eg telephone network
33
Packet Switching
bull data sent out of sequence
bull small chunks (packets) of data at a time
bull packets passed from node to node between source and destination
bull used for terminal to computer and computer to computer communications
34
Frame Relay
bull packet switching systems have large overheads to compensate for errors
bull modern systems are more reliable
bull errors can be caught in end system
bull Frame Relay provides higher speeds
bull with most error control overhead removed
35
Asynchronous Transfer Mode(ATM)
bull evolution of frame relay
bull fixed packet (called cell) length
bull with little overhead for error control
bull anything from 10Mbps to Gbps
bull constant data rate using packet switching technique with multiple virtual circuits
36
Figure 111 WANs a switched WAN and a point-to-point WAN
37
Figure 112 A heterogeneous network made of four WANs and two LANs
38
Categories of Networks(cont)
bull Metropolitan Area Networks
bull MAN towncity
bull High-speed backbone linking multiple LANrsquos DSL TV cables
39
1-3 THE INTERNET1-3 THE INTERNET
The The InternetInternet has revolutionized many aspects of our has revolutionized many aspects of our daily lives It has affected the way we do business as well as the daily lives It has affected the way we do business as well as the way we spend our leisure time The Internet is a way we spend our leisure time The Internet is a communication system that has brought a wealth of communication system that has brought a wealth of information to our fingertips and organized it for our use information to our fingertips and organized it for our use
A Brief History The Internet Today (ISPs)
Topics discussed in this sectionTopics discussed in this section
40
The Internet
bull Internet evolved from ARPANETndash first operational packet networkndash applied to tactical radio amp satellite nets alsondash had a need for interoperabilityndash lead to standardized TCPIP protocols
41
The Internet
bull Huge number of interconnected Networks (100000rsquos) private organized egrsquo government schools research facilities in many countries
bull Collection of LANrsquoS MANrsquoS and WANrsquos ndash 1048708 The internet protocol stack is the TCPIP ndash 1048708 End users use the internet via Internet Service providers
(ISPs) which are of the following hierarchies
42
Figure 113 Hierarchical organization of the Internet
43
Internet Elements
44
Internet Architecture
45
Example Configuration
46
1-4 PROTOCOLS AND STANDARDS1-4 PROTOCOLS AND STANDARDS
In this section we define two widely used terms In this section we define two widely used terms protocolsprotocols and and standardsstandards First we define protocol which is synonymous with First we define protocol which is synonymous with rule Then we discuss standards which are agreed-upon rulesrule Then we discuss standards which are agreed-upon rules
ProtocolsStandardsStandards OrganizationsInternet Standards
Topics discussed in this sectionTopics discussed in this section
47
What is a protocol
Communications between computers requires very specific unambiguous rules A protocol is a set of rules that governs how two or more communicating parties are to interactExamples
Internet Protocol (IP)Transmission Control Protocol (TCP)HyperText Transfer Protocol (HTTP)Simple Mail Transfer Protocol (SMTP)
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
24
Figure 18 A ring topology connecting six stations
25
bull C) Ring Each device connects Point to Point with only two other devices in a left and right neighbors arrangement via a repeater
bull Advantages easy installation better fault isolation and robustness
bull Disadvantages N2 hops communication
26
Figure 19 A hybrid topology a star backbone with three bus networks
27
bull D) Hybrid bull Pizza ldquostarrdquo inside a ldquo ringrdquo
bull Pros Better robustness still low cost Delay is 1 hop (until the star is not with a ring cut max 2 bull Star of busses
28
Categories of Networks
bull Local Area Networks (LAN) Few Kilometers Connects devices (PCs printers servers) within the same room building company and campus
bull Topologies most used are bus ring and star
29
Figure 110 An isolated LAN connecting 12 computers to a hub in a closet
30
Categories of Networks(cont)
bull Wide Area Networks (WAN)
bull span a large geographical area about 100rsquos ndash 1000rsquos of Km
bull 1) Switched End users connected via a cloud of switches (subnet)
bull 2) Point-to Point Line leased from telephone company TV connecting users
to the ISP for Internet access
31
bull alternative technologies used includendash circuit switchingndash packet switchingndash frame relayndash Asynchronous Transfer Mode (ATM)
32
Circuit Switching
bull uses a dedicated communications path established for duration of conversation
bull comprising a sequence of physical links
bull with a dedicated logical channel
bull eg telephone network
33
Packet Switching
bull data sent out of sequence
bull small chunks (packets) of data at a time
bull packets passed from node to node between source and destination
bull used for terminal to computer and computer to computer communications
34
Frame Relay
bull packet switching systems have large overheads to compensate for errors
bull modern systems are more reliable
bull errors can be caught in end system
bull Frame Relay provides higher speeds
bull with most error control overhead removed
35
Asynchronous Transfer Mode(ATM)
bull evolution of frame relay
bull fixed packet (called cell) length
bull with little overhead for error control
bull anything from 10Mbps to Gbps
bull constant data rate using packet switching technique with multiple virtual circuits
36
Figure 111 WANs a switched WAN and a point-to-point WAN
37
Figure 112 A heterogeneous network made of four WANs and two LANs
38
Categories of Networks(cont)
bull Metropolitan Area Networks
bull MAN towncity
bull High-speed backbone linking multiple LANrsquos DSL TV cables
39
1-3 THE INTERNET1-3 THE INTERNET
The The InternetInternet has revolutionized many aspects of our has revolutionized many aspects of our daily lives It has affected the way we do business as well as the daily lives It has affected the way we do business as well as the way we spend our leisure time The Internet is a way we spend our leisure time The Internet is a communication system that has brought a wealth of communication system that has brought a wealth of information to our fingertips and organized it for our use information to our fingertips and organized it for our use
A Brief History The Internet Today (ISPs)
Topics discussed in this sectionTopics discussed in this section
40
The Internet
bull Internet evolved from ARPANETndash first operational packet networkndash applied to tactical radio amp satellite nets alsondash had a need for interoperabilityndash lead to standardized TCPIP protocols
41
The Internet
bull Huge number of interconnected Networks (100000rsquos) private organized egrsquo government schools research facilities in many countries
bull Collection of LANrsquoS MANrsquoS and WANrsquos ndash 1048708 The internet protocol stack is the TCPIP ndash 1048708 End users use the internet via Internet Service providers
(ISPs) which are of the following hierarchies
42
Figure 113 Hierarchical organization of the Internet
43
Internet Elements
44
Internet Architecture
45
Example Configuration
46
1-4 PROTOCOLS AND STANDARDS1-4 PROTOCOLS AND STANDARDS
In this section we define two widely used terms In this section we define two widely used terms protocolsprotocols and and standardsstandards First we define protocol which is synonymous with First we define protocol which is synonymous with rule Then we discuss standards which are agreed-upon rulesrule Then we discuss standards which are agreed-upon rules
ProtocolsStandardsStandards OrganizationsInternet Standards
Topics discussed in this sectionTopics discussed in this section
47
What is a protocol
Communications between computers requires very specific unambiguous rules A protocol is a set of rules that governs how two or more communicating parties are to interactExamples
Internet Protocol (IP)Transmission Control Protocol (TCP)HyperText Transfer Protocol (HTTP)Simple Mail Transfer Protocol (SMTP)
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
25
bull C) Ring Each device connects Point to Point with only two other devices in a left and right neighbors arrangement via a repeater
bull Advantages easy installation better fault isolation and robustness
bull Disadvantages N2 hops communication
26
Figure 19 A hybrid topology a star backbone with three bus networks
27
bull D) Hybrid bull Pizza ldquostarrdquo inside a ldquo ringrdquo
bull Pros Better robustness still low cost Delay is 1 hop (until the star is not with a ring cut max 2 bull Star of busses
28
Categories of Networks
bull Local Area Networks (LAN) Few Kilometers Connects devices (PCs printers servers) within the same room building company and campus
bull Topologies most used are bus ring and star
29
Figure 110 An isolated LAN connecting 12 computers to a hub in a closet
30
Categories of Networks(cont)
bull Wide Area Networks (WAN)
bull span a large geographical area about 100rsquos ndash 1000rsquos of Km
bull 1) Switched End users connected via a cloud of switches (subnet)
bull 2) Point-to Point Line leased from telephone company TV connecting users
to the ISP for Internet access
31
bull alternative technologies used includendash circuit switchingndash packet switchingndash frame relayndash Asynchronous Transfer Mode (ATM)
32
Circuit Switching
bull uses a dedicated communications path established for duration of conversation
bull comprising a sequence of physical links
bull with a dedicated logical channel
bull eg telephone network
33
Packet Switching
bull data sent out of sequence
bull small chunks (packets) of data at a time
bull packets passed from node to node between source and destination
bull used for terminal to computer and computer to computer communications
34
Frame Relay
bull packet switching systems have large overheads to compensate for errors
bull modern systems are more reliable
bull errors can be caught in end system
bull Frame Relay provides higher speeds
bull with most error control overhead removed
35
Asynchronous Transfer Mode(ATM)
bull evolution of frame relay
bull fixed packet (called cell) length
bull with little overhead for error control
bull anything from 10Mbps to Gbps
bull constant data rate using packet switching technique with multiple virtual circuits
36
Figure 111 WANs a switched WAN and a point-to-point WAN
37
Figure 112 A heterogeneous network made of four WANs and two LANs
38
Categories of Networks(cont)
bull Metropolitan Area Networks
bull MAN towncity
bull High-speed backbone linking multiple LANrsquos DSL TV cables
39
1-3 THE INTERNET1-3 THE INTERNET
The The InternetInternet has revolutionized many aspects of our has revolutionized many aspects of our daily lives It has affected the way we do business as well as the daily lives It has affected the way we do business as well as the way we spend our leisure time The Internet is a way we spend our leisure time The Internet is a communication system that has brought a wealth of communication system that has brought a wealth of information to our fingertips and organized it for our use information to our fingertips and organized it for our use
A Brief History The Internet Today (ISPs)
Topics discussed in this sectionTopics discussed in this section
40
The Internet
bull Internet evolved from ARPANETndash first operational packet networkndash applied to tactical radio amp satellite nets alsondash had a need for interoperabilityndash lead to standardized TCPIP protocols
41
The Internet
bull Huge number of interconnected Networks (100000rsquos) private organized egrsquo government schools research facilities in many countries
bull Collection of LANrsquoS MANrsquoS and WANrsquos ndash 1048708 The internet protocol stack is the TCPIP ndash 1048708 End users use the internet via Internet Service providers
(ISPs) which are of the following hierarchies
42
Figure 113 Hierarchical organization of the Internet
43
Internet Elements
44
Internet Architecture
45
Example Configuration
46
1-4 PROTOCOLS AND STANDARDS1-4 PROTOCOLS AND STANDARDS
In this section we define two widely used terms In this section we define two widely used terms protocolsprotocols and and standardsstandards First we define protocol which is synonymous with First we define protocol which is synonymous with rule Then we discuss standards which are agreed-upon rulesrule Then we discuss standards which are agreed-upon rules
ProtocolsStandardsStandards OrganizationsInternet Standards
Topics discussed in this sectionTopics discussed in this section
47
What is a protocol
Communications between computers requires very specific unambiguous rules A protocol is a set of rules that governs how two or more communicating parties are to interactExamples
Internet Protocol (IP)Transmission Control Protocol (TCP)HyperText Transfer Protocol (HTTP)Simple Mail Transfer Protocol (SMTP)
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
26
Figure 19 A hybrid topology a star backbone with three bus networks
27
bull D) Hybrid bull Pizza ldquostarrdquo inside a ldquo ringrdquo
bull Pros Better robustness still low cost Delay is 1 hop (until the star is not with a ring cut max 2 bull Star of busses
28
Categories of Networks
bull Local Area Networks (LAN) Few Kilometers Connects devices (PCs printers servers) within the same room building company and campus
bull Topologies most used are bus ring and star
29
Figure 110 An isolated LAN connecting 12 computers to a hub in a closet
30
Categories of Networks(cont)
bull Wide Area Networks (WAN)
bull span a large geographical area about 100rsquos ndash 1000rsquos of Km
bull 1) Switched End users connected via a cloud of switches (subnet)
bull 2) Point-to Point Line leased from telephone company TV connecting users
to the ISP for Internet access
31
bull alternative technologies used includendash circuit switchingndash packet switchingndash frame relayndash Asynchronous Transfer Mode (ATM)
32
Circuit Switching
bull uses a dedicated communications path established for duration of conversation
bull comprising a sequence of physical links
bull with a dedicated logical channel
bull eg telephone network
33
Packet Switching
bull data sent out of sequence
bull small chunks (packets) of data at a time
bull packets passed from node to node between source and destination
bull used for terminal to computer and computer to computer communications
34
Frame Relay
bull packet switching systems have large overheads to compensate for errors
bull modern systems are more reliable
bull errors can be caught in end system
bull Frame Relay provides higher speeds
bull with most error control overhead removed
35
Asynchronous Transfer Mode(ATM)
bull evolution of frame relay
bull fixed packet (called cell) length
bull with little overhead for error control
bull anything from 10Mbps to Gbps
bull constant data rate using packet switching technique with multiple virtual circuits
36
Figure 111 WANs a switched WAN and a point-to-point WAN
37
Figure 112 A heterogeneous network made of four WANs and two LANs
38
Categories of Networks(cont)
bull Metropolitan Area Networks
bull MAN towncity
bull High-speed backbone linking multiple LANrsquos DSL TV cables
39
1-3 THE INTERNET1-3 THE INTERNET
The The InternetInternet has revolutionized many aspects of our has revolutionized many aspects of our daily lives It has affected the way we do business as well as the daily lives It has affected the way we do business as well as the way we spend our leisure time The Internet is a way we spend our leisure time The Internet is a communication system that has brought a wealth of communication system that has brought a wealth of information to our fingertips and organized it for our use information to our fingertips and organized it for our use
A Brief History The Internet Today (ISPs)
Topics discussed in this sectionTopics discussed in this section
40
The Internet
bull Internet evolved from ARPANETndash first operational packet networkndash applied to tactical radio amp satellite nets alsondash had a need for interoperabilityndash lead to standardized TCPIP protocols
41
The Internet
bull Huge number of interconnected Networks (100000rsquos) private organized egrsquo government schools research facilities in many countries
bull Collection of LANrsquoS MANrsquoS and WANrsquos ndash 1048708 The internet protocol stack is the TCPIP ndash 1048708 End users use the internet via Internet Service providers
(ISPs) which are of the following hierarchies
42
Figure 113 Hierarchical organization of the Internet
43
Internet Elements
44
Internet Architecture
45
Example Configuration
46
1-4 PROTOCOLS AND STANDARDS1-4 PROTOCOLS AND STANDARDS
In this section we define two widely used terms In this section we define two widely used terms protocolsprotocols and and standardsstandards First we define protocol which is synonymous with First we define protocol which is synonymous with rule Then we discuss standards which are agreed-upon rulesrule Then we discuss standards which are agreed-upon rules
ProtocolsStandardsStandards OrganizationsInternet Standards
Topics discussed in this sectionTopics discussed in this section
47
What is a protocol
Communications between computers requires very specific unambiguous rules A protocol is a set of rules that governs how two or more communicating parties are to interactExamples
Internet Protocol (IP)Transmission Control Protocol (TCP)HyperText Transfer Protocol (HTTP)Simple Mail Transfer Protocol (SMTP)
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
27
bull D) Hybrid bull Pizza ldquostarrdquo inside a ldquo ringrdquo
bull Pros Better robustness still low cost Delay is 1 hop (until the star is not with a ring cut max 2 bull Star of busses
28
Categories of Networks
bull Local Area Networks (LAN) Few Kilometers Connects devices (PCs printers servers) within the same room building company and campus
bull Topologies most used are bus ring and star
29
Figure 110 An isolated LAN connecting 12 computers to a hub in a closet
30
Categories of Networks(cont)
bull Wide Area Networks (WAN)
bull span a large geographical area about 100rsquos ndash 1000rsquos of Km
bull 1) Switched End users connected via a cloud of switches (subnet)
bull 2) Point-to Point Line leased from telephone company TV connecting users
to the ISP for Internet access
31
bull alternative technologies used includendash circuit switchingndash packet switchingndash frame relayndash Asynchronous Transfer Mode (ATM)
32
Circuit Switching
bull uses a dedicated communications path established for duration of conversation
bull comprising a sequence of physical links
bull with a dedicated logical channel
bull eg telephone network
33
Packet Switching
bull data sent out of sequence
bull small chunks (packets) of data at a time
bull packets passed from node to node between source and destination
bull used for terminal to computer and computer to computer communications
34
Frame Relay
bull packet switching systems have large overheads to compensate for errors
bull modern systems are more reliable
bull errors can be caught in end system
bull Frame Relay provides higher speeds
bull with most error control overhead removed
35
Asynchronous Transfer Mode(ATM)
bull evolution of frame relay
bull fixed packet (called cell) length
bull with little overhead for error control
bull anything from 10Mbps to Gbps
bull constant data rate using packet switching technique with multiple virtual circuits
36
Figure 111 WANs a switched WAN and a point-to-point WAN
37
Figure 112 A heterogeneous network made of four WANs and two LANs
38
Categories of Networks(cont)
bull Metropolitan Area Networks
bull MAN towncity
bull High-speed backbone linking multiple LANrsquos DSL TV cables
39
1-3 THE INTERNET1-3 THE INTERNET
The The InternetInternet has revolutionized many aspects of our has revolutionized many aspects of our daily lives It has affected the way we do business as well as the daily lives It has affected the way we do business as well as the way we spend our leisure time The Internet is a way we spend our leisure time The Internet is a communication system that has brought a wealth of communication system that has brought a wealth of information to our fingertips and organized it for our use information to our fingertips and organized it for our use
A Brief History The Internet Today (ISPs)
Topics discussed in this sectionTopics discussed in this section
40
The Internet
bull Internet evolved from ARPANETndash first operational packet networkndash applied to tactical radio amp satellite nets alsondash had a need for interoperabilityndash lead to standardized TCPIP protocols
41
The Internet
bull Huge number of interconnected Networks (100000rsquos) private organized egrsquo government schools research facilities in many countries
bull Collection of LANrsquoS MANrsquoS and WANrsquos ndash 1048708 The internet protocol stack is the TCPIP ndash 1048708 End users use the internet via Internet Service providers
(ISPs) which are of the following hierarchies
42
Figure 113 Hierarchical organization of the Internet
43
Internet Elements
44
Internet Architecture
45
Example Configuration
46
1-4 PROTOCOLS AND STANDARDS1-4 PROTOCOLS AND STANDARDS
In this section we define two widely used terms In this section we define two widely used terms protocolsprotocols and and standardsstandards First we define protocol which is synonymous with First we define protocol which is synonymous with rule Then we discuss standards which are agreed-upon rulesrule Then we discuss standards which are agreed-upon rules
ProtocolsStandardsStandards OrganizationsInternet Standards
Topics discussed in this sectionTopics discussed in this section
47
What is a protocol
Communications between computers requires very specific unambiguous rules A protocol is a set of rules that governs how two or more communicating parties are to interactExamples
Internet Protocol (IP)Transmission Control Protocol (TCP)HyperText Transfer Protocol (HTTP)Simple Mail Transfer Protocol (SMTP)
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
28
Categories of Networks
bull Local Area Networks (LAN) Few Kilometers Connects devices (PCs printers servers) within the same room building company and campus
bull Topologies most used are bus ring and star
29
Figure 110 An isolated LAN connecting 12 computers to a hub in a closet
30
Categories of Networks(cont)
bull Wide Area Networks (WAN)
bull span a large geographical area about 100rsquos ndash 1000rsquos of Km
bull 1) Switched End users connected via a cloud of switches (subnet)
bull 2) Point-to Point Line leased from telephone company TV connecting users
to the ISP for Internet access
31
bull alternative technologies used includendash circuit switchingndash packet switchingndash frame relayndash Asynchronous Transfer Mode (ATM)
32
Circuit Switching
bull uses a dedicated communications path established for duration of conversation
bull comprising a sequence of physical links
bull with a dedicated logical channel
bull eg telephone network
33
Packet Switching
bull data sent out of sequence
bull small chunks (packets) of data at a time
bull packets passed from node to node between source and destination
bull used for terminal to computer and computer to computer communications
34
Frame Relay
bull packet switching systems have large overheads to compensate for errors
bull modern systems are more reliable
bull errors can be caught in end system
bull Frame Relay provides higher speeds
bull with most error control overhead removed
35
Asynchronous Transfer Mode(ATM)
bull evolution of frame relay
bull fixed packet (called cell) length
bull with little overhead for error control
bull anything from 10Mbps to Gbps
bull constant data rate using packet switching technique with multiple virtual circuits
36
Figure 111 WANs a switched WAN and a point-to-point WAN
37
Figure 112 A heterogeneous network made of four WANs and two LANs
38
Categories of Networks(cont)
bull Metropolitan Area Networks
bull MAN towncity
bull High-speed backbone linking multiple LANrsquos DSL TV cables
39
1-3 THE INTERNET1-3 THE INTERNET
The The InternetInternet has revolutionized many aspects of our has revolutionized many aspects of our daily lives It has affected the way we do business as well as the daily lives It has affected the way we do business as well as the way we spend our leisure time The Internet is a way we spend our leisure time The Internet is a communication system that has brought a wealth of communication system that has brought a wealth of information to our fingertips and organized it for our use information to our fingertips and organized it for our use
A Brief History The Internet Today (ISPs)
Topics discussed in this sectionTopics discussed in this section
40
The Internet
bull Internet evolved from ARPANETndash first operational packet networkndash applied to tactical radio amp satellite nets alsondash had a need for interoperabilityndash lead to standardized TCPIP protocols
41
The Internet
bull Huge number of interconnected Networks (100000rsquos) private organized egrsquo government schools research facilities in many countries
bull Collection of LANrsquoS MANrsquoS and WANrsquos ndash 1048708 The internet protocol stack is the TCPIP ndash 1048708 End users use the internet via Internet Service providers
(ISPs) which are of the following hierarchies
42
Figure 113 Hierarchical organization of the Internet
43
Internet Elements
44
Internet Architecture
45
Example Configuration
46
1-4 PROTOCOLS AND STANDARDS1-4 PROTOCOLS AND STANDARDS
In this section we define two widely used terms In this section we define two widely used terms protocolsprotocols and and standardsstandards First we define protocol which is synonymous with First we define protocol which is synonymous with rule Then we discuss standards which are agreed-upon rulesrule Then we discuss standards which are agreed-upon rules
ProtocolsStandardsStandards OrganizationsInternet Standards
Topics discussed in this sectionTopics discussed in this section
47
What is a protocol
Communications between computers requires very specific unambiguous rules A protocol is a set of rules that governs how two or more communicating parties are to interactExamples
Internet Protocol (IP)Transmission Control Protocol (TCP)HyperText Transfer Protocol (HTTP)Simple Mail Transfer Protocol (SMTP)
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
29
Figure 110 An isolated LAN connecting 12 computers to a hub in a closet
30
Categories of Networks(cont)
bull Wide Area Networks (WAN)
bull span a large geographical area about 100rsquos ndash 1000rsquos of Km
bull 1) Switched End users connected via a cloud of switches (subnet)
bull 2) Point-to Point Line leased from telephone company TV connecting users
to the ISP for Internet access
31
bull alternative technologies used includendash circuit switchingndash packet switchingndash frame relayndash Asynchronous Transfer Mode (ATM)
32
Circuit Switching
bull uses a dedicated communications path established for duration of conversation
bull comprising a sequence of physical links
bull with a dedicated logical channel
bull eg telephone network
33
Packet Switching
bull data sent out of sequence
bull small chunks (packets) of data at a time
bull packets passed from node to node between source and destination
bull used for terminal to computer and computer to computer communications
34
Frame Relay
bull packet switching systems have large overheads to compensate for errors
bull modern systems are more reliable
bull errors can be caught in end system
bull Frame Relay provides higher speeds
bull with most error control overhead removed
35
Asynchronous Transfer Mode(ATM)
bull evolution of frame relay
bull fixed packet (called cell) length
bull with little overhead for error control
bull anything from 10Mbps to Gbps
bull constant data rate using packet switching technique with multiple virtual circuits
36
Figure 111 WANs a switched WAN and a point-to-point WAN
37
Figure 112 A heterogeneous network made of four WANs and two LANs
38
Categories of Networks(cont)
bull Metropolitan Area Networks
bull MAN towncity
bull High-speed backbone linking multiple LANrsquos DSL TV cables
39
1-3 THE INTERNET1-3 THE INTERNET
The The InternetInternet has revolutionized many aspects of our has revolutionized many aspects of our daily lives It has affected the way we do business as well as the daily lives It has affected the way we do business as well as the way we spend our leisure time The Internet is a way we spend our leisure time The Internet is a communication system that has brought a wealth of communication system that has brought a wealth of information to our fingertips and organized it for our use information to our fingertips and organized it for our use
A Brief History The Internet Today (ISPs)
Topics discussed in this sectionTopics discussed in this section
40
The Internet
bull Internet evolved from ARPANETndash first operational packet networkndash applied to tactical radio amp satellite nets alsondash had a need for interoperabilityndash lead to standardized TCPIP protocols
41
The Internet
bull Huge number of interconnected Networks (100000rsquos) private organized egrsquo government schools research facilities in many countries
bull Collection of LANrsquoS MANrsquoS and WANrsquos ndash 1048708 The internet protocol stack is the TCPIP ndash 1048708 End users use the internet via Internet Service providers
(ISPs) which are of the following hierarchies
42
Figure 113 Hierarchical organization of the Internet
43
Internet Elements
44
Internet Architecture
45
Example Configuration
46
1-4 PROTOCOLS AND STANDARDS1-4 PROTOCOLS AND STANDARDS
In this section we define two widely used terms In this section we define two widely used terms protocolsprotocols and and standardsstandards First we define protocol which is synonymous with First we define protocol which is synonymous with rule Then we discuss standards which are agreed-upon rulesrule Then we discuss standards which are agreed-upon rules
ProtocolsStandardsStandards OrganizationsInternet Standards
Topics discussed in this sectionTopics discussed in this section
47
What is a protocol
Communications between computers requires very specific unambiguous rules A protocol is a set of rules that governs how two or more communicating parties are to interactExamples
Internet Protocol (IP)Transmission Control Protocol (TCP)HyperText Transfer Protocol (HTTP)Simple Mail Transfer Protocol (SMTP)
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
30
Categories of Networks(cont)
bull Wide Area Networks (WAN)
bull span a large geographical area about 100rsquos ndash 1000rsquos of Km
bull 1) Switched End users connected via a cloud of switches (subnet)
bull 2) Point-to Point Line leased from telephone company TV connecting users
to the ISP for Internet access
31
bull alternative technologies used includendash circuit switchingndash packet switchingndash frame relayndash Asynchronous Transfer Mode (ATM)
32
Circuit Switching
bull uses a dedicated communications path established for duration of conversation
bull comprising a sequence of physical links
bull with a dedicated logical channel
bull eg telephone network
33
Packet Switching
bull data sent out of sequence
bull small chunks (packets) of data at a time
bull packets passed from node to node between source and destination
bull used for terminal to computer and computer to computer communications
34
Frame Relay
bull packet switching systems have large overheads to compensate for errors
bull modern systems are more reliable
bull errors can be caught in end system
bull Frame Relay provides higher speeds
bull with most error control overhead removed
35
Asynchronous Transfer Mode(ATM)
bull evolution of frame relay
bull fixed packet (called cell) length
bull with little overhead for error control
bull anything from 10Mbps to Gbps
bull constant data rate using packet switching technique with multiple virtual circuits
36
Figure 111 WANs a switched WAN and a point-to-point WAN
37
Figure 112 A heterogeneous network made of four WANs and two LANs
38
Categories of Networks(cont)
bull Metropolitan Area Networks
bull MAN towncity
bull High-speed backbone linking multiple LANrsquos DSL TV cables
39
1-3 THE INTERNET1-3 THE INTERNET
The The InternetInternet has revolutionized many aspects of our has revolutionized many aspects of our daily lives It has affected the way we do business as well as the daily lives It has affected the way we do business as well as the way we spend our leisure time The Internet is a way we spend our leisure time The Internet is a communication system that has brought a wealth of communication system that has brought a wealth of information to our fingertips and organized it for our use information to our fingertips and organized it for our use
A Brief History The Internet Today (ISPs)
Topics discussed in this sectionTopics discussed in this section
40
The Internet
bull Internet evolved from ARPANETndash first operational packet networkndash applied to tactical radio amp satellite nets alsondash had a need for interoperabilityndash lead to standardized TCPIP protocols
41
The Internet
bull Huge number of interconnected Networks (100000rsquos) private organized egrsquo government schools research facilities in many countries
bull Collection of LANrsquoS MANrsquoS and WANrsquos ndash 1048708 The internet protocol stack is the TCPIP ndash 1048708 End users use the internet via Internet Service providers
(ISPs) which are of the following hierarchies
42
Figure 113 Hierarchical organization of the Internet
43
Internet Elements
44
Internet Architecture
45
Example Configuration
46
1-4 PROTOCOLS AND STANDARDS1-4 PROTOCOLS AND STANDARDS
In this section we define two widely used terms In this section we define two widely used terms protocolsprotocols and and standardsstandards First we define protocol which is synonymous with First we define protocol which is synonymous with rule Then we discuss standards which are agreed-upon rulesrule Then we discuss standards which are agreed-upon rules
ProtocolsStandardsStandards OrganizationsInternet Standards
Topics discussed in this sectionTopics discussed in this section
47
What is a protocol
Communications between computers requires very specific unambiguous rules A protocol is a set of rules that governs how two or more communicating parties are to interactExamples
Internet Protocol (IP)Transmission Control Protocol (TCP)HyperText Transfer Protocol (HTTP)Simple Mail Transfer Protocol (SMTP)
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
31
bull alternative technologies used includendash circuit switchingndash packet switchingndash frame relayndash Asynchronous Transfer Mode (ATM)
32
Circuit Switching
bull uses a dedicated communications path established for duration of conversation
bull comprising a sequence of physical links
bull with a dedicated logical channel
bull eg telephone network
33
Packet Switching
bull data sent out of sequence
bull small chunks (packets) of data at a time
bull packets passed from node to node between source and destination
bull used for terminal to computer and computer to computer communications
34
Frame Relay
bull packet switching systems have large overheads to compensate for errors
bull modern systems are more reliable
bull errors can be caught in end system
bull Frame Relay provides higher speeds
bull with most error control overhead removed
35
Asynchronous Transfer Mode(ATM)
bull evolution of frame relay
bull fixed packet (called cell) length
bull with little overhead for error control
bull anything from 10Mbps to Gbps
bull constant data rate using packet switching technique with multiple virtual circuits
36
Figure 111 WANs a switched WAN and a point-to-point WAN
37
Figure 112 A heterogeneous network made of four WANs and two LANs
38
Categories of Networks(cont)
bull Metropolitan Area Networks
bull MAN towncity
bull High-speed backbone linking multiple LANrsquos DSL TV cables
39
1-3 THE INTERNET1-3 THE INTERNET
The The InternetInternet has revolutionized many aspects of our has revolutionized many aspects of our daily lives It has affected the way we do business as well as the daily lives It has affected the way we do business as well as the way we spend our leisure time The Internet is a way we spend our leisure time The Internet is a communication system that has brought a wealth of communication system that has brought a wealth of information to our fingertips and organized it for our use information to our fingertips and organized it for our use
A Brief History The Internet Today (ISPs)
Topics discussed in this sectionTopics discussed in this section
40
The Internet
bull Internet evolved from ARPANETndash first operational packet networkndash applied to tactical radio amp satellite nets alsondash had a need for interoperabilityndash lead to standardized TCPIP protocols
41
The Internet
bull Huge number of interconnected Networks (100000rsquos) private organized egrsquo government schools research facilities in many countries
bull Collection of LANrsquoS MANrsquoS and WANrsquos ndash 1048708 The internet protocol stack is the TCPIP ndash 1048708 End users use the internet via Internet Service providers
(ISPs) which are of the following hierarchies
42
Figure 113 Hierarchical organization of the Internet
43
Internet Elements
44
Internet Architecture
45
Example Configuration
46
1-4 PROTOCOLS AND STANDARDS1-4 PROTOCOLS AND STANDARDS
In this section we define two widely used terms In this section we define two widely used terms protocolsprotocols and and standardsstandards First we define protocol which is synonymous with First we define protocol which is synonymous with rule Then we discuss standards which are agreed-upon rulesrule Then we discuss standards which are agreed-upon rules
ProtocolsStandardsStandards OrganizationsInternet Standards
Topics discussed in this sectionTopics discussed in this section
47
What is a protocol
Communications between computers requires very specific unambiguous rules A protocol is a set of rules that governs how two or more communicating parties are to interactExamples
Internet Protocol (IP)Transmission Control Protocol (TCP)HyperText Transfer Protocol (HTTP)Simple Mail Transfer Protocol (SMTP)
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
32
Circuit Switching
bull uses a dedicated communications path established for duration of conversation
bull comprising a sequence of physical links
bull with a dedicated logical channel
bull eg telephone network
33
Packet Switching
bull data sent out of sequence
bull small chunks (packets) of data at a time
bull packets passed from node to node between source and destination
bull used for terminal to computer and computer to computer communications
34
Frame Relay
bull packet switching systems have large overheads to compensate for errors
bull modern systems are more reliable
bull errors can be caught in end system
bull Frame Relay provides higher speeds
bull with most error control overhead removed
35
Asynchronous Transfer Mode(ATM)
bull evolution of frame relay
bull fixed packet (called cell) length
bull with little overhead for error control
bull anything from 10Mbps to Gbps
bull constant data rate using packet switching technique with multiple virtual circuits
36
Figure 111 WANs a switched WAN and a point-to-point WAN
37
Figure 112 A heterogeneous network made of four WANs and two LANs
38
Categories of Networks(cont)
bull Metropolitan Area Networks
bull MAN towncity
bull High-speed backbone linking multiple LANrsquos DSL TV cables
39
1-3 THE INTERNET1-3 THE INTERNET
The The InternetInternet has revolutionized many aspects of our has revolutionized many aspects of our daily lives It has affected the way we do business as well as the daily lives It has affected the way we do business as well as the way we spend our leisure time The Internet is a way we spend our leisure time The Internet is a communication system that has brought a wealth of communication system that has brought a wealth of information to our fingertips and organized it for our use information to our fingertips and organized it for our use
A Brief History The Internet Today (ISPs)
Topics discussed in this sectionTopics discussed in this section
40
The Internet
bull Internet evolved from ARPANETndash first operational packet networkndash applied to tactical radio amp satellite nets alsondash had a need for interoperabilityndash lead to standardized TCPIP protocols
41
The Internet
bull Huge number of interconnected Networks (100000rsquos) private organized egrsquo government schools research facilities in many countries
bull Collection of LANrsquoS MANrsquoS and WANrsquos ndash 1048708 The internet protocol stack is the TCPIP ndash 1048708 End users use the internet via Internet Service providers
(ISPs) which are of the following hierarchies
42
Figure 113 Hierarchical organization of the Internet
43
Internet Elements
44
Internet Architecture
45
Example Configuration
46
1-4 PROTOCOLS AND STANDARDS1-4 PROTOCOLS AND STANDARDS
In this section we define two widely used terms In this section we define two widely used terms protocolsprotocols and and standardsstandards First we define protocol which is synonymous with First we define protocol which is synonymous with rule Then we discuss standards which are agreed-upon rulesrule Then we discuss standards which are agreed-upon rules
ProtocolsStandardsStandards OrganizationsInternet Standards
Topics discussed in this sectionTopics discussed in this section
47
What is a protocol
Communications between computers requires very specific unambiguous rules A protocol is a set of rules that governs how two or more communicating parties are to interactExamples
Internet Protocol (IP)Transmission Control Protocol (TCP)HyperText Transfer Protocol (HTTP)Simple Mail Transfer Protocol (SMTP)
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
33
Packet Switching
bull data sent out of sequence
bull small chunks (packets) of data at a time
bull packets passed from node to node between source and destination
bull used for terminal to computer and computer to computer communications
34
Frame Relay
bull packet switching systems have large overheads to compensate for errors
bull modern systems are more reliable
bull errors can be caught in end system
bull Frame Relay provides higher speeds
bull with most error control overhead removed
35
Asynchronous Transfer Mode(ATM)
bull evolution of frame relay
bull fixed packet (called cell) length
bull with little overhead for error control
bull anything from 10Mbps to Gbps
bull constant data rate using packet switching technique with multiple virtual circuits
36
Figure 111 WANs a switched WAN and a point-to-point WAN
37
Figure 112 A heterogeneous network made of four WANs and two LANs
38
Categories of Networks(cont)
bull Metropolitan Area Networks
bull MAN towncity
bull High-speed backbone linking multiple LANrsquos DSL TV cables
39
1-3 THE INTERNET1-3 THE INTERNET
The The InternetInternet has revolutionized many aspects of our has revolutionized many aspects of our daily lives It has affected the way we do business as well as the daily lives It has affected the way we do business as well as the way we spend our leisure time The Internet is a way we spend our leisure time The Internet is a communication system that has brought a wealth of communication system that has brought a wealth of information to our fingertips and organized it for our use information to our fingertips and organized it for our use
A Brief History The Internet Today (ISPs)
Topics discussed in this sectionTopics discussed in this section
40
The Internet
bull Internet evolved from ARPANETndash first operational packet networkndash applied to tactical radio amp satellite nets alsondash had a need for interoperabilityndash lead to standardized TCPIP protocols
41
The Internet
bull Huge number of interconnected Networks (100000rsquos) private organized egrsquo government schools research facilities in many countries
bull Collection of LANrsquoS MANrsquoS and WANrsquos ndash 1048708 The internet protocol stack is the TCPIP ndash 1048708 End users use the internet via Internet Service providers
(ISPs) which are of the following hierarchies
42
Figure 113 Hierarchical organization of the Internet
43
Internet Elements
44
Internet Architecture
45
Example Configuration
46
1-4 PROTOCOLS AND STANDARDS1-4 PROTOCOLS AND STANDARDS
In this section we define two widely used terms In this section we define two widely used terms protocolsprotocols and and standardsstandards First we define protocol which is synonymous with First we define protocol which is synonymous with rule Then we discuss standards which are agreed-upon rulesrule Then we discuss standards which are agreed-upon rules
ProtocolsStandardsStandards OrganizationsInternet Standards
Topics discussed in this sectionTopics discussed in this section
47
What is a protocol
Communications between computers requires very specific unambiguous rules A protocol is a set of rules that governs how two or more communicating parties are to interactExamples
Internet Protocol (IP)Transmission Control Protocol (TCP)HyperText Transfer Protocol (HTTP)Simple Mail Transfer Protocol (SMTP)
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
34
Frame Relay
bull packet switching systems have large overheads to compensate for errors
bull modern systems are more reliable
bull errors can be caught in end system
bull Frame Relay provides higher speeds
bull with most error control overhead removed
35
Asynchronous Transfer Mode(ATM)
bull evolution of frame relay
bull fixed packet (called cell) length
bull with little overhead for error control
bull anything from 10Mbps to Gbps
bull constant data rate using packet switching technique with multiple virtual circuits
36
Figure 111 WANs a switched WAN and a point-to-point WAN
37
Figure 112 A heterogeneous network made of four WANs and two LANs
38
Categories of Networks(cont)
bull Metropolitan Area Networks
bull MAN towncity
bull High-speed backbone linking multiple LANrsquos DSL TV cables
39
1-3 THE INTERNET1-3 THE INTERNET
The The InternetInternet has revolutionized many aspects of our has revolutionized many aspects of our daily lives It has affected the way we do business as well as the daily lives It has affected the way we do business as well as the way we spend our leisure time The Internet is a way we spend our leisure time The Internet is a communication system that has brought a wealth of communication system that has brought a wealth of information to our fingertips and organized it for our use information to our fingertips and organized it for our use
A Brief History The Internet Today (ISPs)
Topics discussed in this sectionTopics discussed in this section
40
The Internet
bull Internet evolved from ARPANETndash first operational packet networkndash applied to tactical radio amp satellite nets alsondash had a need for interoperabilityndash lead to standardized TCPIP protocols
41
The Internet
bull Huge number of interconnected Networks (100000rsquos) private organized egrsquo government schools research facilities in many countries
bull Collection of LANrsquoS MANrsquoS and WANrsquos ndash 1048708 The internet protocol stack is the TCPIP ndash 1048708 End users use the internet via Internet Service providers
(ISPs) which are of the following hierarchies
42
Figure 113 Hierarchical organization of the Internet
43
Internet Elements
44
Internet Architecture
45
Example Configuration
46
1-4 PROTOCOLS AND STANDARDS1-4 PROTOCOLS AND STANDARDS
In this section we define two widely used terms In this section we define two widely used terms protocolsprotocols and and standardsstandards First we define protocol which is synonymous with First we define protocol which is synonymous with rule Then we discuss standards which are agreed-upon rulesrule Then we discuss standards which are agreed-upon rules
ProtocolsStandardsStandards OrganizationsInternet Standards
Topics discussed in this sectionTopics discussed in this section
47
What is a protocol
Communications between computers requires very specific unambiguous rules A protocol is a set of rules that governs how two or more communicating parties are to interactExamples
Internet Protocol (IP)Transmission Control Protocol (TCP)HyperText Transfer Protocol (HTTP)Simple Mail Transfer Protocol (SMTP)
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
35
Asynchronous Transfer Mode(ATM)
bull evolution of frame relay
bull fixed packet (called cell) length
bull with little overhead for error control
bull anything from 10Mbps to Gbps
bull constant data rate using packet switching technique with multiple virtual circuits
36
Figure 111 WANs a switched WAN and a point-to-point WAN
37
Figure 112 A heterogeneous network made of four WANs and two LANs
38
Categories of Networks(cont)
bull Metropolitan Area Networks
bull MAN towncity
bull High-speed backbone linking multiple LANrsquos DSL TV cables
39
1-3 THE INTERNET1-3 THE INTERNET
The The InternetInternet has revolutionized many aspects of our has revolutionized many aspects of our daily lives It has affected the way we do business as well as the daily lives It has affected the way we do business as well as the way we spend our leisure time The Internet is a way we spend our leisure time The Internet is a communication system that has brought a wealth of communication system that has brought a wealth of information to our fingertips and organized it for our use information to our fingertips and organized it for our use
A Brief History The Internet Today (ISPs)
Topics discussed in this sectionTopics discussed in this section
40
The Internet
bull Internet evolved from ARPANETndash first operational packet networkndash applied to tactical radio amp satellite nets alsondash had a need for interoperabilityndash lead to standardized TCPIP protocols
41
The Internet
bull Huge number of interconnected Networks (100000rsquos) private organized egrsquo government schools research facilities in many countries
bull Collection of LANrsquoS MANrsquoS and WANrsquos ndash 1048708 The internet protocol stack is the TCPIP ndash 1048708 End users use the internet via Internet Service providers
(ISPs) which are of the following hierarchies
42
Figure 113 Hierarchical organization of the Internet
43
Internet Elements
44
Internet Architecture
45
Example Configuration
46
1-4 PROTOCOLS AND STANDARDS1-4 PROTOCOLS AND STANDARDS
In this section we define two widely used terms In this section we define two widely used terms protocolsprotocols and and standardsstandards First we define protocol which is synonymous with First we define protocol which is synonymous with rule Then we discuss standards which are agreed-upon rulesrule Then we discuss standards which are agreed-upon rules
ProtocolsStandardsStandards OrganizationsInternet Standards
Topics discussed in this sectionTopics discussed in this section
47
What is a protocol
Communications between computers requires very specific unambiguous rules A protocol is a set of rules that governs how two or more communicating parties are to interactExamples
Internet Protocol (IP)Transmission Control Protocol (TCP)HyperText Transfer Protocol (HTTP)Simple Mail Transfer Protocol (SMTP)
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
36
Figure 111 WANs a switched WAN and a point-to-point WAN
37
Figure 112 A heterogeneous network made of four WANs and two LANs
38
Categories of Networks(cont)
bull Metropolitan Area Networks
bull MAN towncity
bull High-speed backbone linking multiple LANrsquos DSL TV cables
39
1-3 THE INTERNET1-3 THE INTERNET
The The InternetInternet has revolutionized many aspects of our has revolutionized many aspects of our daily lives It has affected the way we do business as well as the daily lives It has affected the way we do business as well as the way we spend our leisure time The Internet is a way we spend our leisure time The Internet is a communication system that has brought a wealth of communication system that has brought a wealth of information to our fingertips and organized it for our use information to our fingertips and organized it for our use
A Brief History The Internet Today (ISPs)
Topics discussed in this sectionTopics discussed in this section
40
The Internet
bull Internet evolved from ARPANETndash first operational packet networkndash applied to tactical radio amp satellite nets alsondash had a need for interoperabilityndash lead to standardized TCPIP protocols
41
The Internet
bull Huge number of interconnected Networks (100000rsquos) private organized egrsquo government schools research facilities in many countries
bull Collection of LANrsquoS MANrsquoS and WANrsquos ndash 1048708 The internet protocol stack is the TCPIP ndash 1048708 End users use the internet via Internet Service providers
(ISPs) which are of the following hierarchies
42
Figure 113 Hierarchical organization of the Internet
43
Internet Elements
44
Internet Architecture
45
Example Configuration
46
1-4 PROTOCOLS AND STANDARDS1-4 PROTOCOLS AND STANDARDS
In this section we define two widely used terms In this section we define two widely used terms protocolsprotocols and and standardsstandards First we define protocol which is synonymous with First we define protocol which is synonymous with rule Then we discuss standards which are agreed-upon rulesrule Then we discuss standards which are agreed-upon rules
ProtocolsStandardsStandards OrganizationsInternet Standards
Topics discussed in this sectionTopics discussed in this section
47
What is a protocol
Communications between computers requires very specific unambiguous rules A protocol is a set of rules that governs how two or more communicating parties are to interactExamples
Internet Protocol (IP)Transmission Control Protocol (TCP)HyperText Transfer Protocol (HTTP)Simple Mail Transfer Protocol (SMTP)
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
37
Figure 112 A heterogeneous network made of four WANs and two LANs
38
Categories of Networks(cont)
bull Metropolitan Area Networks
bull MAN towncity
bull High-speed backbone linking multiple LANrsquos DSL TV cables
39
1-3 THE INTERNET1-3 THE INTERNET
The The InternetInternet has revolutionized many aspects of our has revolutionized many aspects of our daily lives It has affected the way we do business as well as the daily lives It has affected the way we do business as well as the way we spend our leisure time The Internet is a way we spend our leisure time The Internet is a communication system that has brought a wealth of communication system that has brought a wealth of information to our fingertips and organized it for our use information to our fingertips and organized it for our use
A Brief History The Internet Today (ISPs)
Topics discussed in this sectionTopics discussed in this section
40
The Internet
bull Internet evolved from ARPANETndash first operational packet networkndash applied to tactical radio amp satellite nets alsondash had a need for interoperabilityndash lead to standardized TCPIP protocols
41
The Internet
bull Huge number of interconnected Networks (100000rsquos) private organized egrsquo government schools research facilities in many countries
bull Collection of LANrsquoS MANrsquoS and WANrsquos ndash 1048708 The internet protocol stack is the TCPIP ndash 1048708 End users use the internet via Internet Service providers
(ISPs) which are of the following hierarchies
42
Figure 113 Hierarchical organization of the Internet
43
Internet Elements
44
Internet Architecture
45
Example Configuration
46
1-4 PROTOCOLS AND STANDARDS1-4 PROTOCOLS AND STANDARDS
In this section we define two widely used terms In this section we define two widely used terms protocolsprotocols and and standardsstandards First we define protocol which is synonymous with First we define protocol which is synonymous with rule Then we discuss standards which are agreed-upon rulesrule Then we discuss standards which are agreed-upon rules
ProtocolsStandardsStandards OrganizationsInternet Standards
Topics discussed in this sectionTopics discussed in this section
47
What is a protocol
Communications between computers requires very specific unambiguous rules A protocol is a set of rules that governs how two or more communicating parties are to interactExamples
Internet Protocol (IP)Transmission Control Protocol (TCP)HyperText Transfer Protocol (HTTP)Simple Mail Transfer Protocol (SMTP)
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
38
Categories of Networks(cont)
bull Metropolitan Area Networks
bull MAN towncity
bull High-speed backbone linking multiple LANrsquos DSL TV cables
39
1-3 THE INTERNET1-3 THE INTERNET
The The InternetInternet has revolutionized many aspects of our has revolutionized many aspects of our daily lives It has affected the way we do business as well as the daily lives It has affected the way we do business as well as the way we spend our leisure time The Internet is a way we spend our leisure time The Internet is a communication system that has brought a wealth of communication system that has brought a wealth of information to our fingertips and organized it for our use information to our fingertips and organized it for our use
A Brief History The Internet Today (ISPs)
Topics discussed in this sectionTopics discussed in this section
40
The Internet
bull Internet evolved from ARPANETndash first operational packet networkndash applied to tactical radio amp satellite nets alsondash had a need for interoperabilityndash lead to standardized TCPIP protocols
41
The Internet
bull Huge number of interconnected Networks (100000rsquos) private organized egrsquo government schools research facilities in many countries
bull Collection of LANrsquoS MANrsquoS and WANrsquos ndash 1048708 The internet protocol stack is the TCPIP ndash 1048708 End users use the internet via Internet Service providers
(ISPs) which are of the following hierarchies
42
Figure 113 Hierarchical organization of the Internet
43
Internet Elements
44
Internet Architecture
45
Example Configuration
46
1-4 PROTOCOLS AND STANDARDS1-4 PROTOCOLS AND STANDARDS
In this section we define two widely used terms In this section we define two widely used terms protocolsprotocols and and standardsstandards First we define protocol which is synonymous with First we define protocol which is synonymous with rule Then we discuss standards which are agreed-upon rulesrule Then we discuss standards which are agreed-upon rules
ProtocolsStandardsStandards OrganizationsInternet Standards
Topics discussed in this sectionTopics discussed in this section
47
What is a protocol
Communications between computers requires very specific unambiguous rules A protocol is a set of rules that governs how two or more communicating parties are to interactExamples
Internet Protocol (IP)Transmission Control Protocol (TCP)HyperText Transfer Protocol (HTTP)Simple Mail Transfer Protocol (SMTP)
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
39
1-3 THE INTERNET1-3 THE INTERNET
The The InternetInternet has revolutionized many aspects of our has revolutionized many aspects of our daily lives It has affected the way we do business as well as the daily lives It has affected the way we do business as well as the way we spend our leisure time The Internet is a way we spend our leisure time The Internet is a communication system that has brought a wealth of communication system that has brought a wealth of information to our fingertips and organized it for our use information to our fingertips and organized it for our use
A Brief History The Internet Today (ISPs)
Topics discussed in this sectionTopics discussed in this section
40
The Internet
bull Internet evolved from ARPANETndash first operational packet networkndash applied to tactical radio amp satellite nets alsondash had a need for interoperabilityndash lead to standardized TCPIP protocols
41
The Internet
bull Huge number of interconnected Networks (100000rsquos) private organized egrsquo government schools research facilities in many countries
bull Collection of LANrsquoS MANrsquoS and WANrsquos ndash 1048708 The internet protocol stack is the TCPIP ndash 1048708 End users use the internet via Internet Service providers
(ISPs) which are of the following hierarchies
42
Figure 113 Hierarchical organization of the Internet
43
Internet Elements
44
Internet Architecture
45
Example Configuration
46
1-4 PROTOCOLS AND STANDARDS1-4 PROTOCOLS AND STANDARDS
In this section we define two widely used terms In this section we define two widely used terms protocolsprotocols and and standardsstandards First we define protocol which is synonymous with First we define protocol which is synonymous with rule Then we discuss standards which are agreed-upon rulesrule Then we discuss standards which are agreed-upon rules
ProtocolsStandardsStandards OrganizationsInternet Standards
Topics discussed in this sectionTopics discussed in this section
47
What is a protocol
Communications between computers requires very specific unambiguous rules A protocol is a set of rules that governs how two or more communicating parties are to interactExamples
Internet Protocol (IP)Transmission Control Protocol (TCP)HyperText Transfer Protocol (HTTP)Simple Mail Transfer Protocol (SMTP)
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
40
The Internet
bull Internet evolved from ARPANETndash first operational packet networkndash applied to tactical radio amp satellite nets alsondash had a need for interoperabilityndash lead to standardized TCPIP protocols
41
The Internet
bull Huge number of interconnected Networks (100000rsquos) private organized egrsquo government schools research facilities in many countries
bull Collection of LANrsquoS MANrsquoS and WANrsquos ndash 1048708 The internet protocol stack is the TCPIP ndash 1048708 End users use the internet via Internet Service providers
(ISPs) which are of the following hierarchies
42
Figure 113 Hierarchical organization of the Internet
43
Internet Elements
44
Internet Architecture
45
Example Configuration
46
1-4 PROTOCOLS AND STANDARDS1-4 PROTOCOLS AND STANDARDS
In this section we define two widely used terms In this section we define two widely used terms protocolsprotocols and and standardsstandards First we define protocol which is synonymous with First we define protocol which is synonymous with rule Then we discuss standards which are agreed-upon rulesrule Then we discuss standards which are agreed-upon rules
ProtocolsStandardsStandards OrganizationsInternet Standards
Topics discussed in this sectionTopics discussed in this section
47
What is a protocol
Communications between computers requires very specific unambiguous rules A protocol is a set of rules that governs how two or more communicating parties are to interactExamples
Internet Protocol (IP)Transmission Control Protocol (TCP)HyperText Transfer Protocol (HTTP)Simple Mail Transfer Protocol (SMTP)
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
41
The Internet
bull Huge number of interconnected Networks (100000rsquos) private organized egrsquo government schools research facilities in many countries
bull Collection of LANrsquoS MANrsquoS and WANrsquos ndash 1048708 The internet protocol stack is the TCPIP ndash 1048708 End users use the internet via Internet Service providers
(ISPs) which are of the following hierarchies
42
Figure 113 Hierarchical organization of the Internet
43
Internet Elements
44
Internet Architecture
45
Example Configuration
46
1-4 PROTOCOLS AND STANDARDS1-4 PROTOCOLS AND STANDARDS
In this section we define two widely used terms In this section we define two widely used terms protocolsprotocols and and standardsstandards First we define protocol which is synonymous with First we define protocol which is synonymous with rule Then we discuss standards which are agreed-upon rulesrule Then we discuss standards which are agreed-upon rules
ProtocolsStandardsStandards OrganizationsInternet Standards
Topics discussed in this sectionTopics discussed in this section
47
What is a protocol
Communications between computers requires very specific unambiguous rules A protocol is a set of rules that governs how two or more communicating parties are to interactExamples
Internet Protocol (IP)Transmission Control Protocol (TCP)HyperText Transfer Protocol (HTTP)Simple Mail Transfer Protocol (SMTP)
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
42
Figure 113 Hierarchical organization of the Internet
43
Internet Elements
44
Internet Architecture
45
Example Configuration
46
1-4 PROTOCOLS AND STANDARDS1-4 PROTOCOLS AND STANDARDS
In this section we define two widely used terms In this section we define two widely used terms protocolsprotocols and and standardsstandards First we define protocol which is synonymous with First we define protocol which is synonymous with rule Then we discuss standards which are agreed-upon rulesrule Then we discuss standards which are agreed-upon rules
ProtocolsStandardsStandards OrganizationsInternet Standards
Topics discussed in this sectionTopics discussed in this section
47
What is a protocol
Communications between computers requires very specific unambiguous rules A protocol is a set of rules that governs how two or more communicating parties are to interactExamples
Internet Protocol (IP)Transmission Control Protocol (TCP)HyperText Transfer Protocol (HTTP)Simple Mail Transfer Protocol (SMTP)
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
43
Internet Elements
44
Internet Architecture
45
Example Configuration
46
1-4 PROTOCOLS AND STANDARDS1-4 PROTOCOLS AND STANDARDS
In this section we define two widely used terms In this section we define two widely used terms protocolsprotocols and and standardsstandards First we define protocol which is synonymous with First we define protocol which is synonymous with rule Then we discuss standards which are agreed-upon rulesrule Then we discuss standards which are agreed-upon rules
ProtocolsStandardsStandards OrganizationsInternet Standards
Topics discussed in this sectionTopics discussed in this section
47
What is a protocol
Communications between computers requires very specific unambiguous rules A protocol is a set of rules that governs how two or more communicating parties are to interactExamples
Internet Protocol (IP)Transmission Control Protocol (TCP)HyperText Transfer Protocol (HTTP)Simple Mail Transfer Protocol (SMTP)
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
44
Internet Architecture
45
Example Configuration
46
1-4 PROTOCOLS AND STANDARDS1-4 PROTOCOLS AND STANDARDS
In this section we define two widely used terms In this section we define two widely used terms protocolsprotocols and and standardsstandards First we define protocol which is synonymous with First we define protocol which is synonymous with rule Then we discuss standards which are agreed-upon rulesrule Then we discuss standards which are agreed-upon rules
ProtocolsStandardsStandards OrganizationsInternet Standards
Topics discussed in this sectionTopics discussed in this section
47
What is a protocol
Communications between computers requires very specific unambiguous rules A protocol is a set of rules that governs how two or more communicating parties are to interactExamples
Internet Protocol (IP)Transmission Control Protocol (TCP)HyperText Transfer Protocol (HTTP)Simple Mail Transfer Protocol (SMTP)
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
45
Example Configuration
46
1-4 PROTOCOLS AND STANDARDS1-4 PROTOCOLS AND STANDARDS
In this section we define two widely used terms In this section we define two widely used terms protocolsprotocols and and standardsstandards First we define protocol which is synonymous with First we define protocol which is synonymous with rule Then we discuss standards which are agreed-upon rulesrule Then we discuss standards which are agreed-upon rules
ProtocolsStandardsStandards OrganizationsInternet Standards
Topics discussed in this sectionTopics discussed in this section
47
What is a protocol
Communications between computers requires very specific unambiguous rules A protocol is a set of rules that governs how two or more communicating parties are to interactExamples
Internet Protocol (IP)Transmission Control Protocol (TCP)HyperText Transfer Protocol (HTTP)Simple Mail Transfer Protocol (SMTP)
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
46
1-4 PROTOCOLS AND STANDARDS1-4 PROTOCOLS AND STANDARDS
In this section we define two widely used terms In this section we define two widely used terms protocolsprotocols and and standardsstandards First we define protocol which is synonymous with First we define protocol which is synonymous with rule Then we discuss standards which are agreed-upon rulesrule Then we discuss standards which are agreed-upon rules
ProtocolsStandardsStandards OrganizationsInternet Standards
Topics discussed in this sectionTopics discussed in this section
47
What is a protocol
Communications between computers requires very specific unambiguous rules A protocol is a set of rules that governs how two or more communicating parties are to interactExamples
Internet Protocol (IP)Transmission Control Protocol (TCP)HyperText Transfer Protocol (HTTP)Simple Mail Transfer Protocol (SMTP)
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
47
What is a protocol
Communications between computers requires very specific unambiguous rules A protocol is a set of rules that governs how two or more communicating parties are to interactExamples
Internet Protocol (IP)Transmission Control Protocol (TCP)HyperText Transfer Protocol (HTTP)Simple Mail Transfer Protocol (SMTP)
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
48
bull Elements
bull 1) Syntax PDU format ndash 2) Semantics The meaning of each PDUrsquos field ndash 3) Timing Synchronization of communication when
PDU is to be transferred and its data rate
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
49
What is a standard
ndash bull A ldquo standard is set of guidelinesrdquo to users and manufactures to ensure interconnectivity
ndash 1) ldquoDefactordquo not approved but widely used (TCPIP)
ndash 2) ldquoDejurerdquo approved by recognized body (IEEE 802X)
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
50
Summary
bull introduced data communications needs
bull communications model
bull defined data communications
bull overview of networks
bull introduce Internet
Top Related