8th Class Computers Science Networking Network Topologies

    Network Topologies

Network topology refers to the way a computer network is laid out, either physically or logically. It defines the way in which network devices are organized geometrically.  

 The following are the types of topologies: 

1.Mesh topology

2. Star topology

3. Bus topology

4. Ring topology  

 Mesh Topology

In mesh topology each node has a dedicated point-to-point link to every other device. The main advantage of a mesh topology is reliability. It provides more security because if any node fails, it does not affect the entire network. The disadvantage of mesh topology is that it is very costly because mesh is related to the amount of cabling and the number of I/O ports required. It is also very complex structure to design. The following figure shows a network that is based on mesh topology:      

  Star Topology

In this topology each node is directly connected with hub. Thus the devices in the network are not directly linked to each other. The main advantage of star topology is that if any node fails, it does not affect the entire network. It's also less expensive than mesh, and hence easy to configure and maintain. The following figure shows a network that is based on star topology:  

 Bus Topology

In this topology all nodes are connected together to the parallel cable by drop lines and taps/T-connectors. The cable is arranged in a straight line and each node connects to the cable with a T-connector.  

  The advantages of bus topology are the following: 

• Low cost because it requires less cable.
• Easy to install.

It is difficult to reconfigure. It has parallel network cable. If the cable breaks, then entire network fails down. The following figure shows a network that is based on bus topology:    

 Ring Topology

In this topology all computers are connected in a ring shape. In this topology each node has an input and an output connection. It contains wiring that allows information to pass from one device to another in a circle or ring. The main advantages of ring topology, it is easy to install and provides good signal quality. The main disadvantages of ring topology: II one node fails or the ring is broken, then the network is down. ?  The following figure shows a network that is based on ring topology: