What are the different types of Network Topology in computer networking?

 Network Topology in computer networking explains how different devices or nodes are connected physically to form a network and the logical flow of information in the network. It is the geometric representation of the relationship of all the links and nodes to one another.

MESH TOPOLOGY:

In Mesh Topology, every device has point-to-point unique connections(links) with every other device. 

• If there are n nodes, then one node will have (n-1) links. 
• n nodes should have n*(n-1) total number of links. But since one link connects two devices, so the number of links for n nodes will be n*(n-1)/2.

ADVANTAGES OF MESH TOPOLOGY:

• Each connection can carry its own data, so there is no traffic problem that occurs when links are shared by multiple devices.
• Failure to one link doesn't affect others as all the connections are independent.
• Every message is transferred through dedicated lines, only the intended recipient can see the messages, so there is no issue of privacy or security.
• Fault isolation and fault identification become much easier.

DISADVANTAGES OF MESH TOPOLOGY:

• Installation and reconfiguration are difficult as every device is connected to every other device through unique connections.
• Large number of I/O ports and cabling is required.
• Takes lots of physical space.
• Hardware required to connect each link can be expensive.

STAR TOPOLOGY

In star topology, there is a central controller called a hub to which every other device is connected point to point. There is no direct link between the devices. One device can send a message to another via the hub.

• If there are n nodes or devices, then there will be n links

ADVANTAGES OF STAR TOPOLOGY:

• Easy to install and reconfigure as compared to mesh topology.
• Less expensive than mesh topology as each device or node requires only one link and one I/O port to connect to other devices.
• If one link fails, then no other link is affected.

DISADVANTAGES OF STAR TOPOLOGY:

• If the hub fails, then the whole system goes dead as all other devices are dependent on the hub.
• Although the number of cables is lesser than mesh topology, the number is still high than some other topologies.

BUS TOPOLOGY:

In bus topology, there is one long cable to which all the devices are connected. The cable acts as a backbone of the network. Nodes are connected to the bus cable by droplines and tap. Droplines are the links that connect the main bus cable and each device.

There will always be one bus cable irrespective of the number of nodes or devices.

ADVANTAGES OF BUS TOPOLOGY:

• Easy installation.
• Lesser number of cables is required than star and mesh topology.

DISADVANTAGES OF BUS TOPOLOGY:

• Signals become weaker to the farthest point of the bus cable from the starting point as some energy is transformed into heat.
• Difficult reconnection and fault isolation.
• A fault or break in the bus cable disables the entire system by disabling all transmissions.

RING TOPOLOGY:

In ring topology, the devices are connected as a ring. Each device has point-to-point connection to only the two devices on either side of it. The signal passes through one device to another in one direction to the destination.

ADVANTAGES OF RING TOPOLOGY:

• Easy to install and reconfigure as each device is connected to only its immediate neighbors.
• Easy fault isolation.

DISADVANTAGES OF RING TOPOLOGY:

• Break in one ring can disable the entire network.

HYBRID TOPOLOGY:

Hybrid topology is obtained from the combination of the above-mentioned topologies. Hybrid topologies have more advantages than the above topologies.