NETWORK TOPOLOGY

• Topology defines the physical or logical arrangement of links in a network.

• Two or more devices connect to a link then these two or more links make a topology.

• The topology of a network is the geometric representation of the relationship of the relationship of all the links and linking devices to each other.

PHYSICAL TOPOLOGY :Physical topology is the placement of the

various components of a network, including device location and cable installation.

LOGICAL TOPOLGY :Logical topology illustrates how data flows within a network, regardless of its physical

design.

BUS TOPOLOGY RING TOPOLOGY STAR TOPOLOGY TREE TOPOLOGY MESH TOPOLOGY

There are basically five types of network topologies:-

• Mesh topologies involve the concept of routes.

• Unlike each of the previous topologies, messages sent on a mesh network can take any of several possible paths from source to destination.

• Some WANs, most notably the Internet, employ mesh routing.

• A mesh network in which every device connects

to every other is called a full mesh.

• This is also known as connected network.• Every node in LAN is connected to all other nodes ,

through a direct cable.

• A fully connected mesh network therefor has n(n-1)/2 physical channels to link n devices.

• Every devices on the network must have (n-1) input/output ports to accommodate that many links.

• It has the highest speed of communication and highest reliability.

• Point to point links make fault identification and fault isolation easy.

• A mesh topology is robust . If one link become unuseable , it does not incapaciate the entire system.

• A mesh topology has privacy or security.

• Main disadvantage of a mesh are related to the amount of cabling and the number of I/O ports needed.

• Since each devices must be connected to every other device , installation and reconfiguration are difficult.

• Due to these reasons this topology has the highest cabling cost.

It is a simplest type of network with the lowest cost.

In bus topology nodes are connected to the bus cable by drop lines and taps .

As signal travels along the backbone some of its energy is transform into heat.

So its become weaker and weakear thus there is a limit on the no of taps,a bus can support.

BUS TOPOLOGY

• Easy in installation.

• Uses less cables than mesh , star and other.

DISADVANTAGE

ADVANTAGE

• Difficulty in reconfiguration fault or break in bus cable stops all transmission

In this topology the computers are connected by as single cable in a circular manner,with each computer connected directly only to its to neighbours.

If a station wants to send to another the message just past through all the stations in between (either clockwise or anticlockwise).

The two ends of cables are joint together.

In this topology coaxial cables are used .

ADVANTAGE

• Easy to install and reconfigure fault isolation is simplified

DISADVANTAGE

A in a ring can disable the entire network.

In this topology the computer are connected in star manner.

The server is placed at the center of star.

In this topology the computer are not directly linked to each other.

The server (centre controller) controls all communications between stations to the network.

Failure of the central controller will disable all communication throughout the whole network .

If ones device wants to send data to another, it sends the data to the controller and then relay the data to other connected device.

ADVANTAGE• Less expansive• Easy to install• Robustness • Fault identification• Less cabling

DISADVANTAGE• If central controller(HUB) fails,entire

network goes down.

• A tree topology is a variation of a star.

• As in star , nodes is a tree are linked to a central hub that controls the traffic to the network.

• In tree every computer is not plugged in to the central hub most of them are connected to the secondary hub.

• In this topology ,the concept of child and parent is applied during communication process.

• A child node can pass information to another child node at the same level through the parent.

• The failure of parent node disables the communication.

• It is more robust in terms of security of information in comparision to star,bus or ring topologies.

• It is having the the best security.• Allow more devices to be attched to a central hub

and therefor increases the distance a signal can travel between devices.

• The good example of tree topolgy can be seen in cable tv technology where the main cable from the main office is divided into main branches and each branch is divided into smaller branches and soon.

Topologies remain an important part of network design theory. You can probably build a home or small business computer network without understanding the difference between a bus design and a star design, but becoming familiarwith the standard topologies gives you abetter understanding of important networking concepts like hubs, broadcasts, and routes.

SOM KRISHNASAFAL SETHVAIBHAV SHIVHARENILESH RANJANRAVI SHANKAR

AVI NASH SI RI T BRANCH