Final Topo Ppt

8/6/2019 Final Topo Ppt

1/34

Key Network Terminology Explained (2)

Node: anything connected to the network, usually a

computer, but it could be a printer or a scanner

Segment: any portion of a network that is separated bya switch, bridge or a router from another part of a

network.

Backbone: the main cabling of a network that all of

the segment connect to. Usually, the backbone iscapable of carrying more information than the

individual segments.

Topology: The way each node is physically connected

to the network


2/34


3/34


4/34

Network Topologies

Contents What is topology?

Types of topology?

Working of topologies

Flow of data with in topologies

Advantages and disadvantages


5/34

What is Topology?

The way devices on the network arephysically connected is known as topology.

or

The physical layout or the way in whichnetwork connections are made is called atopology.


6/34

Four Types of Topology

1. Bus Topology

2. Star Topology

3. R

ing Topology4. Mesh Topology

Types of Topologies


7/34

Bus Topology

In bus topology, all computers or network

nodes are connected to a common

communication medium. This medium is a

central wire called a bus.


8/34

Working of Bus Topology

If one computer wants to send the data toanother computer in the network, it sendsthe data & destination address via the

bus. This data & address move from one end of

the network to the other.

Each computer checks this address&

if itmatches with this computer, the computerkeeps the data. Otherwise.

the data moves to the next computer.


9/34

a network setup using bus topology


10/34

Data Flow

Communication on the bus topology occurs

in the following manner

Sending the signal

Signal bounce back Terminators


11/34

Sending Signal Data is sent to all of the computers on the

network

Transmission of data is bi-directional

Information is accepted only by the computerwhose address matches

Only one computer can send data on the cable at

a time

While two computers are communicating, allother computers remain in wait.


12/34

Signal Bounce

If the signals were allowed to continue, it

would keep bouncing back and forth alongthe cable and stop other computers from

sending signals.

Backing of the signals is called bounceback.


13/34

Terminators

To stop the signals from bouncing,

terminator is placed at each end of thecable to absorb free signals.

Absorbing the signal clears the cable, so

that other computers can send data. Terminators are used to avoid collisions.


14/34

Bus topology uses coaxial cable as a medium.


15/34

Advantages

It is very simple, easy to use & reliable forvery small networks

It is easy to install and configure

Least amount of cable is required toconnect the computers so it is less

expensive It is easy to extend as two cables can be

joined to make a larger cable


16/34

Disadvantages

It can support only a small number of computers.

As the number of computers increases, the

network get slower.

It is difficult to troubleshoot a bus. A cable break,

fault in any one computer or a loose connection

can breakdown the whole network.

Each connector reduces the strength of the

electrical signal


17/34

Star Topology

In star topology all the cables run fromthe computers to a central location,

where they all are connected to a

device called HUB


18/34

Working of Star Topology

If two computers want to share data , the

sender computer sends the data to the hub

& hub sends it to the receiving computer.

Each computer communicate with each

other by a central HUB.

So, hub provide a central connection point

for all computers across a network.


19/34

Star topology uses a separate cable for each

computer, that cable connects a computer

to a central device i.e hub.


20/34

a network setup using star topology


21/34


22/34

Advantages It is easy to modify & new computers can be

added to the central hub or any computer can be

removed without affecting the network. It is usually easy to troubleshoot a star network.

If any computer in the star topology breaks down,the network is not affected.

It is more flexible among the remaining topology. It is much fast topology.

Multiple cable types supported by hubs.


23/34

Disadvantages

If the central hub fails, the whole network

breaks down. Star network requires more communication

cable than any other network.

It is more expensive.


24/34

Ring Topology

Ring topology looks like the bus topologywith connected ends.

But

In functionality it is different.


25/34

Working of Star Topology

Each computer is connected to the nextcomputer in the form of ring.

Each retransmit what it receives from the

previous computer. The message flow in one direction.


26/34

Ring topology connects computers on a

single circle of cable.

There is no terminated ends Signals travel around the loop in one

direction and pass through each computer.

Unlike bus topology, each computer actslike a repeater to boost the signal and

send it to the next computer.


27/34

It is called endless topology.

In ring topology, data flows in ring and in

clock-wise direction. Ring topology is based on Token Ring

Mechanism.


28/34

a network setup using ring topology


29/34

Token Passing.. A token is passed around the network.

The computer that has token can transmitdata.

Token is passed from computer tocomputer until it reaches to its destination.

The destination device returns anacknowledgement to the sender.

The token is then given to another device,giving it ability to transmit.


30/34

The sending computer modified the token,

puts address with the data and sends it

around the ring.

Data passed by each computer until it finds

the computer with an address that matches.

Token is used as a carrier.

It is called token grab.


31/34


32/34

Advantages

All computers on the ring have equal

access to the network. It performs well under a heavy load.


33/34

Disadvantages

Failure of one computer can affect the

whole network. It is difficult to troubleshoot the ring

network.

Adding or removing a computer affects thewhole network.


34/34

a network setup using mesh topology

Documents

Final Topo Ppt