Network Topologies

Each computer or device in a network is called node.The arrangement or connection pattern of computers or nodes and other devices of the network is known as network topology.Speed and performance of the computer network depends upon the topology used.Basic topologies of network are: 1.Bus topology 2.ring topology 3.star topology.
1.Bus topology
In bus topology ,computers and other devices are arranged in a linear format .It uses a common backbone is also called Bus.it works as a communication medium and each workstation is connected with the coaxial cable and "T"connector.Data are transmitted on the network through the backbone using the computer destination address .If the address matches with the workstation address ,It receives the data.If the address does not match, the data passes to the next workstations and so on.
2.Ring topology
In ring topology computers are connected in the shape of the circle without any endpoint .Each workstation contains two neighbors for communication or an input and an output connection. The input connection of the workstation receives data and is transmitted to the next workstation through the output connection.So, in this topology ,the signal travel s in circle passing through each computer o the network because their are no terminates ends to the cable .It supports coaxial ,twisted pair and fiber optic cables.
Ring topology uses a token passing method to pass data from one computers to another .All the computers get equal opportunity to access the token .A workstation that need to transmit data captures the token .Data and destination address are added with the token and sent to the ring .If the destination computer receives the data properly , then it will send a positive acknowledgment .Otherwise ,it sends a negative acknowledgment to the source computer.
3.Star topology
In star topology ,all computer or network devices are connected through a central devices in the shape of a star structure .The common devices used for the central connection are hub and switch .The computer are connected to the hub or switch using unshielded twisted pair,shielded twisted pair or fiber optics cables.This is the most popular network topology used to connect computers and other devices in anetwork .In this topology ,the central point device (hub or switch) may regenerate the signal ,which helps to transfer data to a longer distance.