Lmt 9 Network Protocols
-
Upload
lakshay187 -
Category
Documents
-
view
215 -
download
0
Transcript of Lmt 9 Network Protocols
-
8/14/2019 Lmt 9 Network Protocols
1/23
Network Communicationsand Protocols
1AMIT Kr. BHARDWAJ, LMTSOM
-
8/14/2019 Lmt 9 Network Protocols
2/23
AMIT Kr. BHARDWAJ,LMTSOM
2
Objectives
Explain the function of protocols in anetwork
Describe common protocol suites
-
8/14/2019 Lmt 9 Network Protocols
3/23
AMIT Kr. BHARDWAJ,LMTSOM
3
Protocols
Strictly speaking, protocols are therules and procedures forcommunicating
For two computers to communicate,they must speak the same language andagree on the rules of communication
-
8/14/2019 Lmt 9 Network Protocols
4/23
AMIT Kr. BHARDWAJ,LMTSOM
4
The Function of Protocols
As protocols serve their functions in theOSI model, they might work at one ormany layers
When a set of protocols works
cooperatively, its called a protocol stackor protocol suiteThe most common protocol stack is TCP/IP,
the Internet protocol suite IPX/SPX, used in older versions of Novell
NetWare, is disappearing as companiesupgrade to newer versions of NetWare
Levels of a protocol stack map to theirfunctions in the OSI model
-
8/14/2019 Lmt 9 Network Protocols
5/23
AMIT Kr. BHARDWAJ,LMTSOM
5
Connectionless VersusConnection-Oriented Protocols
Protocols that use connectionless deliveryplace data on the network and assume it willget through Connectionless protocols arent entirely reliable Are fast: little overhead, dont waste time
establishing/managing/tearing down connections Connection-oriented protocols are more
reliable and, consequently, slowerTwo computers establish a connection before data
transfer begins In a connection, data is sent in an orderly fashion
Ensures that all data is received and is accurate, orthat suitable error messages are generated
-
8/14/2019 Lmt 9 Network Protocols
6/23
AMIT Kr. BHARDWAJ,LMTSOM
6
Routable Versus NonroutableProtocols
The network layer (OSI) is responsible formoving data across multiple networks Routers are responsible for routing process
Protocol suites that function at Network
layer are routable or routed protocols;otherwise, they are called nonroutableTCP/IP and IPX/SPX are routable protocols An older and nearly obsolete protocol, NetBEUI,
is a nonroutable protocol that works well insmall networks, but its performance dropsconsiderably as a network grows
-
8/14/2019 Lmt 9 Network Protocols
7/23
AMIT Kr. BHARDWAJ,LMTSOM
7
Protocols in a LayeredArchitecture
-
8/14/2019 Lmt 9 Network Protocols
8/23
AMIT Kr. BHARDWAJ,LMTSOM
8
Protocols in a LayeredArchitecture (continued)
-
8/14/2019 Lmt 9 Network Protocols
9/23
AMIT Kr. BHARDWAJ,LMTSOM
9
Network Protocols
Some popular network protocols include:
Internet Protocol version 4 (IPv4 or simply IP)
Provides addressing and routing information
Internetwork Packet Exchange (IPX)
Novells protocol for packet routing and forwarding Belongs to the IPX/SPX protocol suite
Serves many of the same functions as TCP/IPs IP
Internet Protocol version 6 (IPv6)
A new version of IP thats being implemented on many currentnetworking devices and operating systems
Addresses some weaknesses of IPv4
-
8/14/2019 Lmt 9 Network Protocols
10/23
AMIT Kr. BHARDWAJ,LMTSOM
10
Transport Protocols
Transport protocols can be connection-oriented (reliable) or connectionless (best-effort) delivery Transmission Control Protocol (TCP)
Responsible for reliable data delivery in TCP/IP
Sequential Packet Exchange (SPX) Novells connection-oriented protocol used to
guarantee data delivery
NetBIOS/NetBEUI NetBIOS establishes/manages communications
between computers and provides naming services NetBEUI provides data transport services for these
communications
-
8/14/2019 Lmt 9 Network Protocols
11/23
AMIT Kr. BHARDWAJ,LMTSOM
11
Application Protocols
Application protocols provide services toclient applications
Simple Mail Transport Protocol (SMTP) in TCP/IP
File Transfer Protocol (FTP) in TCP/IP
Simple Network Management Protocol (SNMP) Manages and monitors network devices (TCP/IP)
NetWare Core Protocol (NCP)
Novells client shells and redirectors
AppleTalk File Protocol (AFP) Apples remote file-management protocol
-
8/14/2019 Lmt 9 Network Protocols
12/23
AMIT Kr. BHARDWAJ,LMTSOM
12
Common Protocol Suites
Because most protocols contain acombination of components, thesecomponents are usually bundled as a protocol
suiteTCP/IP
Dominates the networking arena to the point of makingmost of the other suites nearly obsolete
IPX/SPX
NetBIOS/NetBEUI
AppleTalk
T i i C t l
-
8/14/2019 Lmt 9 Network Protocols
13/23
AMIT Kr. BHARDWAJ,LMTSOM
13
Transmission ControlProtocol/Internet Protocol
(TCP/IP)
-
8/14/2019 Lmt 9 Network Protocols
14/23
AMIT Kr. BHARDWAJ,LMTSOM
14
TCP/IP Network LayerProtocols
Internet Protocol version 4 (IPv4) is a Networklayer protocol that provides source anddestination addressing and routing for the TCP/IPsuite Connectionless protocol; fast but unreliable
Internet Control Message Protocol (ICMP) isa Network layer protocol used to send error andcontrol messages between systems or devicesThe Ping utility uses ICMP to request a response from a
remote host to verify availability
Address Resolution Protocol (ARP) resolves
logical (IP) addresses to physical (MAC) addresses
-
8/14/2019 Lmt 9 Network Protocols
15/23
AMIT Kr. BHARDWAJ,LMTSOM
15
IP, ICMP, and ARP in Action
-
8/14/2019 Lmt 9 Network Protocols
16/23
AMIT Kr. BHARDWAJ,LMTSOM
16
IP, ICMP, and ARP in Action(continued)
-
8/14/2019 Lmt 9 Network Protocols
17/23
AMIT Kr. BHARDWAJ,LMTSOM
17
TCP/IP Transport LayerProtocols
Transmission Control Protocol (TCP) is theprimary Internet transport protocol
Connection oriented using a three-way handshake
Message fragmentation and reassembly
Uses acknowledgements to ensure that all data wasreceived and to provide flow control
User Datagram Protocol (UDP) is connectionless
Generally faster, although less reliable, than TCP Doesnt segment data or resequence packets
Doesnt use acknowledgements for reliability
Used by NFS and DNS
-
8/14/2019 Lmt 9 Network Protocols
18/23
AMIT Kr. BHARDWAJ,LMTSOM
18
TCP/IP Application LayerProtocols
Domain Name System (DNS)
Session layer name-to-address resolution protocol
Hypertext Transport Protocol (HTTP)
To transfer Web pages from Web server to browser
File Transfer Protocol (FTP)
For file transfer and directory and file manipulation Telnet
Remote terminal emulation; operates at layers 7-5
Simple Mail Transport Protocol (SMTP)
Operates at layers 7-5; provides messaging services
-
8/14/2019 Lmt 9 Network Protocols
19/23
AMIT Kr. BHARDWAJ,LMTSOM
19
IP Addressing
Logical addresses are 32 bits (4 bytes) long
Each byte is represented as an octet (decimal numberfrom 0 to 255)
Usually represented in dotted decimal notation E.g., 172.24.208.192
Address has two parts: network and host ID
E.g. 172.24.208.192 (172.24.0.0 and 208.192)
Categorized into ranges referred to as classes
Class system provides basis for determining which part ofaddress is the network and which is the host ID
The first octet of an address denotes its class
-
8/14/2019 Lmt 9 Network Protocols
20/23
AMIT Kr. BHARDWAJ,LMTSOM
20
Dynamic Host ConfigurationProtocol (DHCP)
Detailed configuration of devices, keeping track ofassigned addresses and to which machine they wereassigned, etc., is difficult in large networks
DHCP was developed to make this process easier
DHCP server must be configured with a block of availableIP addresses and their subnet masks
Clients must be configured to use DHCP
Broadcast request message is sent on boot
Client leases the address the server assigns to it
If no answer is received, in an APIPA-enabled OS, the computer assigns
itself an address (169.254.x.x)
-
8/14/2019 Lmt 9 Network Protocols
21/23
AMIT Kr. BHARDWAJ,LMTSOM
21
NetBIOS and NetBEUI
-
8/14/2019 Lmt 9 Network Protocols
22/23
AMIT Kr. BHARDWAJ,LMTSOM
22
IPX/SPX
-
8/14/2019 Lmt 9 Network Protocols
23/23
AMIT Kr. BHARDWAJ,LMTSOM
23
Summary
Many protocols are available for networkcommunications, each with itsstrengths/weaknesses
The TCP/IP protocol suite dominates network
communication in part due to its use on theInternet
IP addressing involves several concepts,including address classes, subnetting, andsupernetting
IPv6 will eventually replace IPv4 because itoffers several advantages: 128-bit addressspace, autoconfiguration, built-in security,and QoS