Network topology basically refers to the physical network that is the locations of the computers and how the cable operates between them. For choosing the right topology for how the network will be used is very important. Each topology comprises its own strength and weaknesses.
The choice of a topology for installing a computer network depends upon a combination of factors like performance of the system, reliability, geographical distributions of the system and number of nodes.
The two main types of network are:
Peer to Peer topology and Bus topology
Peer to Peer topology consists of Ring topology and star topology.
It is often used when installation of network is small, temporary or simple. On a typical bus network the cable consists of only one or more wires with no active electronics to strengthen the signal or pass it along from computer to computer. This makes the bus a passive topology. When one computer send a signal, through the wire all the computers get the information but only with the address which matches accepts the information, the rest of the message is ignored.
Following are the advantages of Bus topology:
- It is easy to use and understand.
- It requires least amount of cable to connect the other computers together. Therefore it is less expensive as compared to other cabling arrangements.
- It is easy to extend a bus. Two cables can be joined into one longer cable with a BNC making a longer cable and allowing more computers to join the network.
In this type of topology all the cables operate from the computers to the central location where all of them are connected by a device called switch or hub. All computers on a star network communicate with a central device which resends the message either to all computers or simply to the destination computer. E.g. if it is a hub then it will send to all of them and if it is a switch then it will send only to destination computer. When the greater reliability is needed and when network expansion is expected, star topology is the best.
Following are the advantages of star topology:
- It can modified easily and can add new computers without even disturbing the rest of the network.
- The center of the star network is considered as a good place for diagnosing the faults.
- Single failure of computer does not automatically bring down the entire star network.
Thus, each type of network has its own unique features and they are considered as an essential part of network design speculation.