What Is A Star Network Or Star Topology?

Star topology is one of the most and very common topologies of computer network. Switch or hub is the main central node of the star topology based networks. Hubs or switch acts like a conduit used to transmit and transfer messages. The networks built on the basis of star topology are called star networks.  There are two types of star networks. One is active star networks and the other is passive star networks. In active star networks the central node is active and is capable to tolerate and prevent echo problems. While in passive networks, the central node is not active because of which the attached nodes have to tolerate and prevent all echo related problems. In star networks ratio of network failure is little  than others as all of the systems are always connected to central switch or hub.

Star topology is very much easy to set up and expand. Non-centralized failure never affects whole system.  Faults can easily be detected in star networks. There is no need of packets to travel through unnecessary nodes, so the packets can quickly transfer over the network. Performance wise star networks are very good. But star networks are expensive to build up as extra hardware is required. And the major disadvantage of star networks is that if the central node (either switch or hub) fails, the whole network will get down.

In a start configuration of computer network, there is a host computer which is attached to local computers through multiple communication lines. The computers are not connected to each other and can not communicate directly with each other. The local computers can only communicate only via through the host computer. The routing function is performed by the host computer which centrally controls communication between any two local computers by establishing a logical path between them.

As like with any communication scheme, star topology has its own pros and corns. Some of the advantages of Star topology are:

1) The number of communication lines required to connect 'n' local computer is always 1 less he number of nodes, i.e. communication line requires 'n-1' lines are required.
2) If any of the local computer in the network breaks down then there is no effect on the whole network and the rest of the network is unaffected and works fully functional
3) Transmission delays do not increase between two local computers if new local computers are added in the network because any two local computers are connected only through two links.

An obvious disadvantage of star topology is

1) The whole network depends on the Host computer. If the host computer fails or breaks down then the whole network crashes.

It's a network topology whereby all the computer systems are connected to a central system through a device known as hub

Advantages of Star Network Or Star Topology