Network Topology

Network topology refers to the physical layout of the network i.e. the locations of the computers and how the cable is run between them. To select the right topology for how the network will be used is very important. Each topology has its own strength and weaknesses.

The choice of a topology for installing a computer network depends upon a combination of factors such as, reliability, performance of the system, number of nodes and geographical distribution of the system.

The main 2 types are

Bus Topology & Peer to Peer Topology

Peer to Peer topology consists of Star topology and Ring topology.

Bus Topology

It is often used when network installation is small, simple or temporary. On a typical bus network the cable is just 1 or more wires with no active electronics to amplify the signal or pass it along from computer to computer. This makes the bus a passive topology. When 1 computer send a signal up the wire all the computers receive the information but only one with the address that matches accepts the information, the rest disregard the message.

Advantages:

1) Easy to use and to understand.

2) Requires least amount of cable to connect the computers together. It is therefore less expensive than other cabling arrangements.

3) It is easy to extend a bus; two cables can be joined into 1 longer cable with a BNC, Barrel connector making a longer cable and allowing more computers to join the network.

Disadvantages:

1) Heavy network traffic can slow a bus considerably as only 1 computer can send a message at a time.

2) It is difficult to troubleshoot the bus. A cable break or loose connector causes reflection and stops all the activity.

Star Topology

In this kind of topology all the cables run from the computers to the central location where they are all connected by a device called hub or switch. Each computer on a star network communicates with a central device that resends the message either to each computer or only to the destination computer, e.g. if it is a hub then it will send to all and if it is a switch then it will send to only destination computer.When network expansion is expected and when the greater reliability is needed, star topology is the best.

Advantages:

1) It is easy to modify and add new computers without disturbing the rest of the network.

2)