Computer Network


This section contain notes on following topics


 Network fundamentals



Transmission Media Reference Models



Data Communication









Network Security



















Computer Network
 A computer network is a group of two or more computers connected to each other through some coneecting medium. This means that the computers can communicate with  each other. All computers in a network can send and recieve information.

 Topologies in Computer Network - 
Topology is the arrangement of computers ins network mean how they are connected to each other. They are categorized into the following  types:

  • bus
  • ring
  • star
  • tree
  • mesh

Bus Topology

This type of network  uses a common device to connect all computers. A single cable works as  backbone and  acts as a  shared communication medium on to which devices attach with an interface connector.


Ring Topology

It is in the form of ring where each node is connected exactly with  two neighboring nodes . In this type of topology communication takes place onliy in one direction . Failure of a single node results in the failure of complete network .


Star Topology

In this topology a central connecting device called hub, switch or router  is used as a medium to connect different nodes of network. In this topology whole of the communication is dependent on central hub. Failure of this central hub results in the failure of complete network.

Tree Topology

This type of topology is in the form of tree , in this various star topologies are coneected together using a bus.In this topology if the bus stops functioning , still part of network can function.

Mesh Topology
 As the ame suggests Mesh topology is combined by forming various types of topologies together . It is not dependent on central hub or switch for communication , so networks can still function if a part of it stops functioning .In this a mesage can be communicated using n number of paths.