Thursday 29 January 2015

Computer Knowledge: Network Topology's for Competitive Exams

Network Topology's ( Bus - Ring)


Network Topology: The term "Topology" refers to the way a network is laid out, either physically or logically. Topology can be referred as the geometric arrangement of a computer system. Each computer system in a topology is known as node. Network topology is determined only by the configuration of connections between nodes. In a fully connected network with n nodes, there are n(n-1)/2 direct links.

Bus Topology:

A bus topology is such that there is a single line to which all nodes connected. It is usually used when a network installation is small, simple or temporary. In bus topology, all the network components are connected with a same (single) line. Ethernet is commonly well protocol in networks connected by bus topology.

Advantages of Bus topology are:
  • All the nodes are connected directly, so very short cable length is required.
  • The architecture is very simple and linear.
  • Bus topology can be extended easily on either sides.
  • The cabling cost of bus topology is less and requires the least amount of cable to connect computers.
Disadvantages of Bus topology are:
  • Diagnosis of fault is difficult. It is difficult to find the problem, if any of the node is facing problem in data communication.
  • In case of any fault in data transmission, fault isolation is very difficult. We have check the entire network to find the fault.
  • Becomes slow which increase in number of nodes.
  • The entire network shuts down if there is an error occurs in the main cable.

Ring or Circular Topology

Ring topology is used in high-performance network where large band with is necessary. The protocols used to implement ring topology are Token Ring and Fibre Distributed Data Interface (FDDI). In ring topology, data is transmitted in form of Token over a network. After passing through each node, the data returns to the sending node.

Advantages of ring or circular topology are:
  • Short cable length is required.
  • Suitable for optical fibre as the data flow in one direction.
Disadvantages of ring or circular topology are;
  • In ring topology, each node is connected in a circular way, with its two neighbouring nodes, so when there is transmission problem anywhere in the network, entire network stops functioning.
  • Fault diagnosis is very difficult in a network formed using ring topology.
  • In ring topology, every node has exactly two branches connected to it, the ring is broken and cannot work if one of the nodes on the ring fails.
  • Failure of single computer affects the whole network.
  • Adding or removing the computer disturbs whole network activity.
Note:- We will discuss remaining Three Topology's in coming posts. Happy Reading.....


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