Cndc Lab File(Pankaj)

1

PANKAJ BISHT CSE 7th SEM 45380

PRACTICAL NO. 1

AIM: To study different types of transmission media types.

THEORY: TRANSMISSION MEDIA TYPE:

The first layer (physical layer) of Communication Networks the OSI Seven layer model is

dedicated to the transmission media. Due to the variety of transmission media and network

wiring methods, selecting the most appropriate media can be confusing - what is the optimal

cost-effective solution.

Classes of transmission media:

1.GUIDED(WIRED): The transmission capacity, in terms of either data rate or bandwidth,

depends critically on the distance and on whether the medium is point-to-point or multipoint.

1.1 Twisted pair

1.2 Coaxial cable

1.3 Fiber –optics cable

2


1.1 TWISTED PAIR: The least expensive and most widely used guided transmission medium is

twisted pair. Twisted-pair cable is a type of cabling that is used for telephone communications

and most modern Ethernet networks. A pair of wires forms a circuit that can transmit data. The

pairs are twisted to provide protection against crosstalk, the noise generated by adjacent pairs.

When electrical current flows through a wire, it creates a small, circular magnetic field around

the wire. When two wires in an electrical circuit are placed close together, their magnetic fields

are the exact opposite of each other. Thus, the two magnetic fields cancel each other out. They

also cancel out any outside magnetic fields. Twisting the wires can enhance this cancellation

effect. Using cancellation together with twisting the wires, cable designers can effectively

provide self-shielding for wire pairs within the network media.

TWISTED PAIR CABLE

3


TYPES OF TWISTED PAIR:

1. UTP (unshielded twisted pair):This cable is a medium that is composed of pairs of wires

. UTP cable is used in a variety of networks. Each of the eight individual copper wires in UTP

cable is covered by an insulating material. In addition, the wires in each pair are twisted around

each other.

2.Shielded Twisted-Pair Cable:

Shielded twisted-pair (STP) cable combines the techniques of shielding, cancellation, and wire

twisting. Each pair of wires is wrapped in a metallic foil . The four pairs of wires then are

wrapped in an overall metallic braid or foil, usually 150-ohm cable. As specified for use in

Ethernet network installations, STP reduces electrical noise both within the cable (pair-to-pair

coupling, or crosstalk) and from outside the cable (EMI and RFI). STP usually is installed with

STP data connector, which is created especially for the STP cable. However, STP cabling also

can use the same RJ connectors that UTP uses.

1.2. COAXIAL CABLE

1. Physical Description:

Coaxial cable, like twisted pair, consists of two conductors, but is constructed differently to

permit it to operate over a wider range of frequencies. It consists of a hollow outer cylindrical

conductor that surrounds a single inner wire conductor . The inner conductor is held in place by

either regularly spaced insulating rings or a solid dielectric material. The outer conductor is

covered with a jacket or shield. A single coaxial cable has a diameter of from 1 to 2.5 cm.

Coaxial cable can be used over longer distances and support more stations on a shared line than

twisted pair.

2. Applications:

Coaxial cable is perhaps the most versatile transmission medium and is enjoying

Wide spread use in a wide variety of applications. The most important of these are

• Television distribution

• Long-distance telephone transmission

• Short-run computer system links

• Local area networks

4


3.Transmission Characteristics:

Coaxial cable is used to transmit both analog and digital signals. As can be seen from coaxial

cable has frequency characteristics that are superior to those of twisted pair, and can hence be

used effectively at higher frequencies and data rates. Because of its shielded, concentric

construction, coaxial cable is much less susceptible to interference and crosstalk than twisted

pair. The principal constraints on performance are attenuation, thermal noise, and

intermodulation noise.

5


1.3. OPTICAL FIBER:

1. Physical Description:

An optical fiber is a thin , flexible medium capable of guiding an optical ray. Various glasses and

plastics can be used to make optical fibers. The lowest losses have difficult to manufacture;

higher-loss multi component glass fibers are more economical and still provide good

performance. Plastic fiber is even less costly and can be used for short-haul links, for which

moderately high losses are acceptable. An optical fiber cable has a cylindrical shape and consists

of three concentric sections: the core, the cladding, and the jacket . The core is the innermost

section and consists of one or more very thin strands, or fibers, made of glass or plastic; the core

has a diameter in the range of 8 to Each fiber is surrounded by its own cladding, a glass or plastic

coating that has optical properties different from those of the core. The interface between the

core and cladding acts as a reflector to confine light that would otherwise escape the core. The

outermost layer, surrounding one or a bundle of cladded fibers, is the jacket. The jacket is

composed of plastic and other material layered to protect against moisture, abrasion, crushing,

and other environmental dangers.

2. Applications:

One of the most significant technological breakthroughs in data transmission has been the

development of practical fiber optic communications systems. Optical fiber already enjoys

considerable use in long-distance telecommunications, and its use in military applications is

growing. The continuing improvements in performance and decline in prices, together with the

inherent advantages of optical fiber, have made it increasingly attractive for local area

networking.

2. UNGUIDED MEDIA (WIRELESS):

Unguided media transport electromagnetic waves without using a physical conductor. This type

of communication is often referred to as wireless communication.

6


1.Radio Waves

2.Microwaves

3.Infrared

1. RADIO WAVES: Radio waves are used for multicast communications, such as radio and

Television and paging systems.

2. MICROWAVE: Microwaves are used for unicast communication such as cellular telephones,

satellite networks, and wireless LANs.

3. INFRARED: Infrared signals can be used for short range communication in a closed area

using line-of-sight propagation.

7


PRACTICAL NO. -2

AIM: To study different types of topologies.

THEORY: Computer network topology is the way various components of a network (like

nodes, links, peripherals, etc.) are arranged. Network topologies define the layout, virtual shape

or structure of network, not only physically but also logically. The way in which different

systems and nodes are connected and communicate with each other is determined by topology of

the network. Topology can be physical or logical. Physical Topology is the physical layout of

nodes, workstations and cables in the network; while logical topology is the way information

flows between different components.

Types of Physical Network Topologies

1) Bus Topology

2) Star Topology

3) Ring Topology

4) Mesh Topology

5) Tree Topology

6) Hybrid Topology

1)BUS TOPOLOGY: Bus Topology is the simplest of network topologies. In this type of

topology, all the nodes (computers as well as servers) are connected to the single cable (called

bus), by the help of interface connectors. This central cable is the backbone of the network and is

known as Bus . Every workstation communicates with the other device through this Bus.

http://www.ianswer4u.com/2011/05/bus-topology-advantages-and.html

http://www.ianswer4u.com/2011/05/star-topology-advantages-and.html

http://www.ianswer4u.com/2011/05/ring-topology-advantages-and.html

http://www.ianswer4u.com/2011/05/mesh-topology-advantages-and.html

http://www.ianswer4u.com/2012/01/tree-topology-advantages-and.html

http://www.ianswer4u.com/2012/05/hybrid-topology-advantages-and.html

http://www.ianswer4u.com/2011/05/network-topology-types-of-network.html

8


Advantages of Linear Bus Topology

1) It is easy to set-up and extend bus network.

2) Cable length required for this topology is the least compared to other networks.

3) Bus topology costs very less.

4) Linear Bus network is mostly used in small networks. Good for LAN.

Disadvantages of Linear Bus Topology

1) There is a limit on central cable length and number of nodes that can be connected.

2) Dependency on central cable in this topology has its disadvantages. If the main cable (i.e. bus

) encounters some problem, whole network breaks down.

3) Proper termination is required to dump signals. Use of terminators is must.

2) STAR TOPOLOGY: In Star topology, all the components of network are connected to the

central device called “hub” which may be a hub, a router or a switch. Unlike Bus topology,

where nodes were connected to central cable, here all the workstations are connected to central

device with a point-to-point connection. So it can be said that every computer is indirectly

connected to every other node by the help of “hub”. All the data on the star topology passes

through the central device before reaching the intended destination. Hub acts as a junction to

connect different nodes present in Star Network, and at the same time it manages and controls

whole of the network. Depending on which central device is used, “hub” can act as repeater or

signal booster. Central device can also communicate with other hubs of different network.

Unshielded Twisted Pair (UTP) Ethernet cable is used to connect workstations to central node.

Advantages of Star Topology

1) Easy to connect new nodes or devices. In star topology new nodes can be added easily

without affecting rest of the network. Similarly components can also be removed easily.

2) Centralized management. It helps in monitoring the network.

3) Failure of one node or link doesn‟t affect the rest of network. At the same time its easy to

detect the failure and troubleshoot it.


9


Disadvantages of Star Topology

1) Too much dependency on central device has its own drawbacks. If it fails whole network

goes down.

2) The use of hub, a router or a switch as central device increases the overall cost of the

network.

3) Performance and as well number of nodes which can be added in such topology is

depended on capacity of central device.

3)RING TOPOLOGY: In Ring Topology, all the nodes are connected to each-other in such

a way that they make a closed loop. Each workstation is connected to two other components

on either side, and it communicates with these two adjacent neighbors. Data travels around

the network, in one direction. Sending and receiving of data takes place by the help of

TOKEN.

Token Passing : Token contains a piece of information which along with data is sent by the

source computer. This token then passes to next node, which checks if the signal is intended

to it. If yes, it receives it and passes the empty to into the network, otherwise passes token

along with the data to next node. This process continues until the signal reaches its

intended destination.

The nodes with token are the ones only allowed to send data. Other nodes have to wait for an

empty token to reach them. This network is usually found in offices, schools and small

buildings.

Advantages of Ring Topology

1) This type of network topology is very organized. Each node gets to send the data when it

receives an empty token. This helps to reduces chances of collision. Also in ring topology all

the traffic flows in only one direction at very high speed.

2) Even when the load on the network increases, its performance is better than that of Bus

topology.





10


3) There is no need for network server to control the connectivity between workstations.

4) Additional components do not affect the performance of network.

5) Each computer has equal access to resources.

Disadvantages of Ring Topology

1) Each packet of data must pass through all the computers between source and destination.

This makes it slower than Star topology.

2) If one workstation or port goes down, the entire network gets affected.

3) Network is highly dependent on the wire which connects different components.

4) MAU‟s and network cards are expensive as compared to Ethernet cards and hubs.

4) MESH TOPOLOGY: In a mesh network topology, each of the network node, computer and

other devices, are interconnected with one another. Every node not only sends its own signals but

also relays data from other nodes. In fact a true mesh topology is the one where every node is

connected to every other node in the network. This type of topology is very expensive as there

are many redundant connections, thus it is not mostly used in computer networks. It is commonly

used in wireless networks. Flooding or routing technique is used in mesh topology.

Types of Mesh Network topologies:-

1) Full Mesh Topology:-

In this, like a true mesh, each component is connected to every other component. Even after

considering the redundancy factor and cost of this network, its main advantage is that the

network traffic can be redirected to other nodes if one of the nodes goes down. Full mesh

topology is used only for backbone networks.

2) Partial Mesh Topology:-

This is far more practical as compared to full mesh topology. Here, some of the systems are

connected in similar fashion as in mesh topology while rests of the systems are only connected to

1 or 2 devices. It can be said that in partial mesh, the workstations are „indirectly‟ connected to

other devices. This one is less costly and also reduces redundancy.



11


Advantages of Mesh topology

1) Data can be transmitted from different devices simultaneously. This topology can withstand

high traffic.

2) Even if one of the components fails there is always an alternative present. So data transfer

doesn‟t get affected.

3) Expansion and modification in topology can be done without disrupting other nodes.

Disadvantages of Mesh topology

1) There are high chances of redundancy in many of the network connections.

2) Overall cost of this network is way too high as compared to other network topologies.

3) Set-up and maintenance of this topology is very difficult. Even administration of the network

is tough.

5 ) TREE TOPOLOGY: Tree Topology integrates the characteristics of Star and Bus Topology.

Earlier we saw how in Physical Star network Topology, computers (nodes) are connected by

each other through central hub. And we also saw in Bus Topology, work station devices are

connected by the common cable called Bus. After understanding these two network

configurations, we can understand tree topology better.




12


Advantages of Tree Topology

1. It is an extension of Star and bus Topologies, so in networks where these topologies can't be

implemented individually for reasons related to scalability, tree topology is the best alternative.

2. Expansion of Network is possible and easy.

3. Here, we divide the whole network into segments (star networks), which can be easily

managed and maintained.

Disadvantages of Tree Topology

1.Because of its basic structure, tree topology, relies heavily on the main bus cable, if it breaks

whole network is crippled.

2. As more and more nodes and segments are added, the maintenance becomes difficult.

3. Scalability of the network depends on the type of cable used.

6) HYBRID TOPOLOGY: A network topology is a connection of various links and nodes,

communicating with each other for transfer of data. We also saw various advantages and

disadvantages of Star, Bus, Ring, Mesh and Tree topologies. Hybrid, as the name suggests, is

mixture of two different things. Similarly in this type of topology we integrate two or more

different topologies to form a resultant topology which has good points(as well as weaknesses)

of all the constituent basic topologies rather than having characteristics of one specific topology.

This combination of topologies is done according to the requirements of the organization.

.

Advantages of Hybrid Network Topology

1) Reliable : Unlike other networks, fault detection and troubleshooting is easy in this

type of topology. The part in which fault is detected can be isolated from the rest of

network and required corrective measures can be taken, WITHOUT affecting the

functioning of rest of the network.





http://www.ianswer4u.com/2011/05/mesh-topology-advantages-and.html

http://www.ianswer4u.com/2012/01/tree-topology-advantages-and.html

13


2) Scalable: Its easy to increase the size of network by adding new components, without

disturbing existing architecture.

3) Flexible: Hybrid Network can be designed according to the requirements of the

organization and by optimizing the available resources. Special care can be given to

nodes where traffic is high as well as where chances of fault are high.

4) Effective: Hybrid topology is the combination of two or more topologies, so we can

design it in such a way that strengths of constituent topologies are maximized while there

weaknesses are neutralized.

Disadvantages of Hybrid Topology

1) Complexity of Design: One of the biggest drawback of hybrid topology is its design.

Its not easy to design this type of architecture and its a tough job for designers.

Configuration and installation process needs to be very efficient.

2) Costly Hub: The hubs used to connect two distinct networks, are very expensive.

These hubs are different from usual hubs as they need to be intelligent enough to work

with different architectures and should be function even if a part of network is down.

3) Costly Infrastructure: As hybrid architectures are usually larger in scale, they require a

lot of cables, cooling systems, sophisticate network devices, etc.

14


PRACTICAL NO. 3

AIM: To study Router Configuration using Packet Tracer Simulator.

THEORY & COMMANDS:

Packet Tracer is a powerful emulator that provides all the tools for setting up an efficient

computer network. It works on CLI (Command Line Interface) configuration. As far as its

working modes are concerned then it works in three modes:

User Mode

Privilege Mode

Global Mode

As the name suggests, User Mode is the mode where all the users can work freely (without need

of any password or something like). It deals with initial level settings. On the other side,

Privilege Mode is a high end PT mode which deals with entry level settings of network. It

includes commands for the terminal mode, clock, interface etc. Global Mode has the highest

degree as customization. It is a protected mode which deals with highest level of network

configuration. It allows users to set passwords, interfacing two devices etc.

15


Main Commands used are:

1. En or Enable: This command is used to get switched from User Mode to Privilege

Mode.

2. Show flash: It shows system flash directory.

3. Show version: It shows Cisco Packet Tracer version. We are working on Version 12.4

iteration.

16


4. Show interface: This command shows the connection status with system addressing

details.

5. Show ip interface: It deals with Internet Protocol Processing. It provides detail about

status of working connection ports of device.

6. Show clock: It displays the clock.

7. Clock set: this command is used to edit and set clock for new time.

Syntax: clock set HH:MM:SS & DD:MM:YY

8. Show history: This command shows the history of recently used commands in CLI

terminal.

9. Config t or Config terminal: This command is used to enter to global mode.

10. Hostname: it changes the host name.

Syntax: hostname “new host name”

17


11. No hostname: This command is used when no host name is required. It vanishes all the

changes that are made to host name.

12. Enable password: It is used to enable the password to enter to privilege or global mode.

Its syntax is written as: enable password “password”.

13. Enable secret password: This command is used in combination with enable password

and helps to execute the password properly. Its syntax is: enable password “password”.

14.Service password encryption: This commands shows the password in aster sticks.

15.No enable password: Used to remove the password. Syntax is: no enable password

“password”

18


PRACTICAL NO.4

AIM-: To study router to router configuration.

STEPS:-

1. Take two routers.

2. Double click on first router.

3. Now a window is displayed. After that turn off the switch.

4. Drag the WIC-2T module and turn on the switch.

5. Click on CLI command after that enter these commands as shown in fig. below:

19


6. Perform the same steps for second router except the clock rate.Then the router will be

connected successfully and node will blink green.

7. Now use the ping command for success rate.

20


PRACTICAL NO.5

AIM:- To study interfacing of 10 PC‟s with one switch and two routers.

STEPS:-

1. Take two router , one switch and 10 PC‟s.

2. Do connection between two routers by using commands and also connect switch.

3. Now connect the 10 PC‟s with the switch.

4. After that assign the IP to each PC.

5. Now check the success rate by using the ping command.

21


22


PRACTICAL NO.-6

AIM: To study the various protocols in OSI model.

THEORY:

OSI protocols are a family of standards for information exchange. These were developed and

designed by the International Organization of Standardization (ISO). In 1977 the ISO model was

introduced, which consisted of seven different layers. Each layer of the ISO model has its own

protocols and functions. The OSI protocol stack was later adapted into the TCP/IP stack. In some

networks, protocols are still popular using only the data link and network layers of the OSI

model.

The OSI protocol stack works on a hierarchical form, from the hardware physical layer to the

software application layer. There are a total of seven layers. Data and information are received

by each layer from an upper layer. After the required processing, this layer then passes the

information on to the next lower layer. A header is added to the forwarded message for the

convenience of the next layer. Each header consists of information such as source and

destination addresses, protocol used, sequence number and other flow-control related data.

The following are the OSI protocols used in the seven layers of the OSI Model:

7 Layers of OSI

THE 7 LAYERS OF OSI

Transmit

Sender Receiver Receive

Application LAYER 7 Application

Presentation LAYER 6 Presentation

Session LAYER 5 Session

Transport LAYER 4 Transport

Network LAYER 3 Network

Data link LAYER 2 Data link

Physical LAYER 1 Physical

23


The ISO (International Organization for Standardization) decided to construct a framework of

standards in which different vendors would be able to use in order to communicate over a

network consisting of diverse equipment and applications. This framework is now considered

the standard for communication of networks. The OSI is divided into 7 layers, which divides the

task into smaller more manageable task groups. Each task or group of tasks assigned to each

layer can also be implemented independently. This limits complications between layers because

the solutions offered by one layer do not adversely affect the other layers.

LAYER 7 - APPLICATION LAYER

The application level provides services that directly support the user applications, such as user

interface, e-mail, file transfer, database access, etc. There are many protocols at this layer that are

commonly needed such as HTTP, WWW, FTP, TELNET, SMTP. It gives applications access to

the network through the layers below. Another important function is file transfer between

computers. Some computers store file names or represent text lines differently. The application

layer takes care of the incompatibilities and allows a smooth transfer between systems.

Protocols: FTP, HTTP, SMTP, DNS, TFTP, NFS, TELNET.

1 .FTP (File Transfer Protocol) - Used to transfer files over the internet using TCP/IP.

2. HTTP (Hypertext Transfer Protocol) - Underlining protocol used by the World Wide Web.

Allows Web servers and browsers to communicate with each other.

3. SMTP (Simple Mail Transfer Protocol) - Protocol used to send email messages between

servers.

4. DNS (Domain Name Service) - An internet service that translates domain names, such as

www.yahoo.com, into IP addresses.

5. TFTP (Trivial File Transfer Protocol) - Simplified version of the FTP protocol which has

no security features.

6. NFS (Network File System) - Client/Server application designed by SUN

MICROSYSTEMS to allow all network users to access files stored on different computer

types.

7. Telnet - terminal emulation program that allows you to connect to a server and enter

information and commands similar to if you were actually on the server terminal.

LAYER 6 - PRESENTATION LAYER

The presentation level is translator between the application and network format. Unlike the lower

layers, its concern is with the syntax and semantics of the information transmitted. Most user

programs do not exchange random binary bit strings. They exchange data such as names,

addresses, dates, etc. Different computers store the data in a different way. In order to allow

these computers to transmit the data to each other the presentation layer translates the data into a

standard form to be used on the network. Another function is data compression which can be

used to reduce the number of bits needed to send the packet of information. Security is also

24


added at this layer by using data encryption and decryption. This prevents others from

intercepting the data and being able to decipher the meaning of the bits.

Protocols: ASCII, EBCDIC, MIDI, MPEG, JPEG

1. ASCII - a code for representing English characters as numbers.

2. EBCDIC (Extended Binary-Coded Decimal Interchange Code) - IBM code for representing

characters as numbers.

3. MIDI (Musical Instrument Device Interface) - adopted by the electronic music industry for

controlling devices, such as synthesizers and sound cards, that emit music.

4. MPEG (Moving Pictures Experts Group) - the family of digital video compression standards

and file formats developed by the ISO group.

5. JPEG (Joint Photographic Experts Group) - a lossy compression format for color images that

reduces file size by 5% while losing some image detail.

LAYER 5 – SESSION LAYER

This layer allows applications on connecting systems to communicate using a session. It opens,

uses, and closes this communication link. It also acts as a dialog control mechanism controlling

who is able to transmit. Sessions can allow data to be sent in both directions at the same time or

only one direction. The session layer determines who has the ability to transfer at the current

time. Another valuable ability is to insert checkpoints during data transfers. During a large file

transmission if the system crashes the checkpoints allow the system to start downloading at the

last known checkpoint. An example of this is during either a interactive login or file transfer

connection, the session would recognize names in the session and register them into a history. It

could then connect and reconnect in case of a system crash at either of the systems.

Protocols: SQL, RPC.

1.SQL (Structured Query Language) - a standardized query language for requesting

information from a database.

2. RPC (Remote Procedure Call) - allows a program on one computer execute a program on a

server.

LAYER 4 – TRANSPORT LAYER

The basic function of the transport layer is to accept data from the session layer, break up the

data into smaller units if need be, and send these manageable data packets to the network layer.

At the destination this layer is responsible for combining the packets into their original state.

This layer also checks to see if the layers are in the right order when received and not in

duplicated form. If there is an error in one of the packets there is a request for that packet's

retransmission. There are two protocols that sit at this layer. First, the TCP protocol connects the

sender and the receiver using a socket which is determined by the IP address and port number.

TCP keeps track of the packet delivery order and which ones need to be resent. UDP on the other

hand is a connectionless communication and does not guarantee packet delivery between sender

25


and receiver. Because it is connectionless the sender sends the data into the network with an IP

address of the receiver and hopes it makes it to its destination. Since there is not a way of asking

the sender to retransmit because of an error there is little error protection if any.

Protocols: TCP or UDP.

1. TCP (Transmission Control Protocol) - enables two to establish a connection and exchange

streams of data.

2. UDP (User Datagram Protocol) - offering a direct way to send and receive datagrams over

an IP network with very few error recovery services.

LAYER 3 - NETWORK LAYER

The network layer basically handles all of the addressing issues. This layer addresses packets,

determines the best path or route, and manages network problems such as data congestion. There

are three ways in which the packets are routed to their destinations. First, there could be a static

route through the entire network that will never be changed. Second, there could be a static line

only used during a particular session between the sender and receiver. Finally, the packets could

be dynamically sent through the network using changing paths in order to prevent bottlenecks.

The bottlenecks are formed when there are too many packets present in one subnet causing them

to get in each other's way. The network level is also responsible for converting the network

address and names to the MAC addresses of the machines. One of the most important functions

of this layer is the ability to allow two different networks using conflicting addressing schemes

to be able to send data to each other. The network layer allows the different protocols to "talk" to

each other and understand where the packet's destination is. Routers work at this level by

sending the packets along the network.

Protocols: IP, ICMP, ARP, PING, Traceroute.

1.IP (Internet Protocol) - specifies the format of packets and the addressing schemes.

2.ICMP (Internet Control Message Protocol) - an extension of IP which supports packets

containing error, control, and informational messages.

3. ARP (Address Resolution Protocol) - used to convert an IP address to a physical address.

4. PING - a utility to check if an IP address is accessible.

5. Traceroute - utility that tracks a packet from your computer to an internet host showing how

many hops and how long it took.

LAYER 2 - DATA LINK LAYER:

The data link layer defines the format of data on the network. All of the data sent through the

network are made into a frame which is performed at this level. The frame is a uniform way of

sending the data along with address information and error checking capabilities. CRC is used for

the error detection at this level. If at the receiving end the CRC fails at this level there is a

26


request back to the sender for retransmission of this packet.

Protocols: IEEE 802.2, 802.3, 802.5.

1. IEEE 802.2 - divides the data link layer into two sublayers -- the logical link control (LLC)

layer and the media access control (MAC) layer.

2.802.3 - Defines the MAC layer for bus networks that use CSMA/CD. This is the basis of the

Ethernet standard.

3.802.5 - Defines the MAC layer for token-ring networks.

LAYER 1 – PHYSICAL LAYER

The physical layer is responsible for establishing, maintaining and ending physical connections

(point to point) between computers. This layer is concerned with the actual interpretation of the

bit stream into an electrical signal that can be carried across a physical medium. The protocols at

this layer deal with the binary transmission, voltage levels, and data rates. This layer would also

specify physical medium properties such as cables and network cards.

Protocols: IEEE 802.3, 802.5.

Cndc Lab File(Pankaj)

Documents

Transcript of Cndc Lab File(Pankaj)