The Network Topologies is a geometric representation of the relationship among the interconnected devices. The configuration, or topology, of a network, is key to determining its performance. Network Topologies is the way a network is arranged including the physical or logical description of how links and nodes are set up to relate to each other.

The four basic Network Topologies are bus, star,ring and mesh.

Bus Topology:

Bus Topology
Bus Topology

A bus topology connects all devices of the Network Topologies through a single common cable having exactly two endpoints. This cable is called the backbone of the topology. Bus topology offers a simple way to connect devices. All of the devices of the Network Topologies are connected to a common transmission medium which has exactly two endpoints. In this simple form of Network Topologies, failure of any single device does not affect other devices connected with the cable. However, if there is some problem in the shared communication cable, then all other devices can stop functioning. It is also called a linear bus topology.

Advantages:

  1. It is cost-effective.
  2. Cable required is least compared to other Network Topologies.
  3. Used in small networks.
  4. It is easy to understand.
  5. Easy to expand joining two cables together.
  6. It is easy to add another device.
  7. Easy installation, each cable needs to be connected with backbone cable.

Disadvantages:

  1. The entire system shut down if there is a break in the main cable and it can be tough to identify the problem if the network shut down.
  2. It uses a single cable to transmit data that is not secure.
  3. Bus topology is suitable for small networks but it can create a problem for complex or large networks.
  4. Data is “half-duplex,” which means it can’t be sent in two opposite directions at the same time, so this layout is not the ideal choice for networks with huge amounts of traffic.
  5. Cable has a limited length.
  6. It is slower than the ring topology.
  7. If the network traffic is heavy, it increases collisions in the network.

Ring Topology:

Ring Topology
Ring Topology

A ring topology connects a computer with exactly two other computers forming a ring of computers. A computer can send data to its immediate neighbour. A ring can be unidirectional or bidirectional. In a unidirectional, ring topology, data is sent either clockwise or anticlockwise. In a bidirectional ring topology, data can travel in any direction. Upon receiving data, a computer may pass its data to its neighbour. In this way, data reach to its destination. Failure of connection between two computers may down the whole network. Unlike star topology, it does not require a central device to manage the connectivity between the devices.

Advantages:

  1. The transmitting network is not affected by high traffic.
  2. For adding more nodes only those nodes having tokens can transmit data.
  3. Cheap to install and expand.
  4. Managing is easier as to add or remove a device from the Network Topologies only two links are required to be changed.
  5. The possibility of collision is minimum in this type of Network Topologies.

Disadvantages:

  1. A link failure can fail the entire network as the signal will not travel forward due failure.
  2. Data traffic issue when all the data is circulation in a ring.
  3. Troubleshooting is difficult
  4. Addition or removal of stations can disturb whole ring topology.

Star Topology:

Star Topology
Star Topology

A star topology connects all devices using point to point connection via cables to a central point. The central point is known as Hub or Switch. The central device controls all the traffic. Therefore, devices can transfer data to each other only through the central point. It is an easy way to install and reconfigure. Star topology consumes more cables than the bus topology.however, if there is some problem in a cable, then only the respective computer gets disconnected from the network. On the other hand, if there is some problem in the hub or switch then the whole network becomes dead.

Advantages:

1. Less expensive
2. Easier to install
3. Less amount of cables required because each device needs to be connected with the hub only.
4. It is Robust if one link fails, other links will not affect.
5. Easy fault detection because the link can be easily identified.

Disadvanges:

  1. If the hub goes down everything goes down, none of the devices can work without a hub.
  2. Hub requires more resources and regular maintenance because it is the central system of star topology.

Mesh Topology:

Mesh Topology
Mesh Topology

This topology connects all devices with each other through a direct link. As compared to ring topology data may reach its destination quickly. The mesh topology is expensive in terms of cable cost as it uses a lengthy cable to connect computers as compared to the cable uses in other topologies. However, the mesh topology is more reliable as it offers a point-to-point connection. It is also considered more secure as data transfers only between a sender and receiver.

Advantages:

1. No data traffic issues as there is a dedicated link between two devices
2. Mesh topology is reliable and robust as failure of one link doesn’t affect other links.
3. Mesh topology is secure.
4. Fault detection is easy.

Disadvantages:

  1. The amount of wires required to connected each system is boring and a headache.
  2. Each device needs to be connected with other devices.
  3. A single device cannot be connected with a large number of devices.

For more detailed information visit these links:

https://www.dnsstuff.com/what-is-network-topology

https://en.wikipedia.org/wiki/Network_topology