The pros and cons of different Network Topologies

Published by Nilofar Pathan on


The network containing many nodes is physically interconnected in a configuration to provide efficient communication, these configurations of interconnecting the nodes in a network are known as network topologies. We discuss few different topologies in this article with the Pros and Cons of different network topologies. While selecting a network topology the following points must be considered.

  1. The cost of physical interconnection.
  2. The time delay during the communications.
  3. Reliability and possibilities of failure.
  4. Network controlling strategy or protocols.

These are many important topologies commonly used while interconnecting computers in a LAN.

Star network topology.

Ring network topology.

Bus network topology.

Mesh network topology.

Hybrid network topology.

Star Network Topology 

This topology of the network is most popular in a LAN network. it is a system containing one common node as a control and many stations connected with the control node in a network-like figure of the star as shown in the following Fig –

LAN is a star topology that has a server or controller (minicomputer) centrally placed (not physically) controlling different PC stations. The main advantage of star topology is that adding a few more nodes is possible and does not affect the time delay. but when the control node fails the whole network fails.

Pros of Star topology:

If N devices are connected to each other in a star topology, then the number of cables required to connect them is N. So, it is easy to set up.

Each device requires only 1 port i.e., to connect to the hub.

cons with Star topology:

If the concentrator (hub) on which the whole topology relies fails, the whole system will crash down.

The cost of installation is high.

Performance is based on the single concentrator i.e., hub.

Ring Network Topology

The ring topology has shown in the following figure where the server is not centrally located. The network is formed by several stations with servers connected one after the other forming a ring route. each node receives data from the ring in sequence, and the data is addressed to get the data to the desired node. In a ring topology, each node is using the common ring to transmit or receive data. suppose node A must be transmitted to node D then it is passed from A to B, B to C and then C to D. Node B&C will check the address if the address is not for them, they retransmit data to the next neighboring station.

The main advantage of ring topology is that each node has direct communication capacity and it is dependent on one control node. But when one terminal fails the whole system fails.

These are the drawback of ring topology but are more reliable than star topology.

Pros of Ring topology:

The possibility of collision is minimum in this type of topology.

Cheap to install and expand.

cons with Ring topology:

Troubleshooting is difficult in this topology.

The addition of stations in between or the removal of stations can disturb the whole topology.

Bus Network Topology

This topology is more efficient and reliable than the star and ring topology. This topology is also known as multipoint or multi-drop topology because, in this interconnection method, a common bus is used for data transmission with bi-directional communication provided by the bus for each node. The bus is available for each node. To send its data to each computer node if desired.

Pros of Bus topology:

If N devices are connected in a bus topology, then the number of cables required to connect them is 1. which is known as backbone cable, and N drop lines are required.

The cost of the cable is less as compared to other topologies, but it is used to build small networks.

cons with Bus topology:

If the common cable fails, then the whole system will crash down. If the network traffic is heavy, it increases collisions in the network.

Mesh Network Topology

In a mesh topology, each device is connected to every other device on the network through a dedicated point-to-point link. When we say dedicated, it means that the link only carries data for the two connected devices. Let us say we have n devices in the network then each device must relate to (n-1) devices of the network. The number of links in a mesh topology of n devices would be n(n-1)/2.

The pros and cons of different network topologies

Pros of Mesh topology:

It is robust.

The fault is diagnosed easily. Data is reliable because data is transferred among the devices through dedicated channels or links.

Provides security and privacy.

cons with Mesh topology:

Installation and configuration are difficult.

The cost of cables is high as bulk wiring is required, hence suitable for a smaller number of devices.

The cost of maintenance is high.

Hybrid Network Topology

Hybrid topology is an integration of two or more different topologies to form a resultant topology that has many advantages (as well as disadvantages) of all the constituent basic topologies rather than having characteristics of one specific topology. This combination of topologies is done according to the requirements of the organization.

Pros of Hybrid topology:

Reliable: Unlike other networks, fault detection and troubleshooting are easy in this type of topology.

Scalable: It is easy to increase the size of the network by adding new components, without disturbing existing architecture.

Flexible: Hybrid networks can be designed according to the requirements of the organization and by optimizing the available resources.

cons with Hybrid topology:

Complexity of Design: One of the biggest drawbacks of hybrid topology is its design. It is not easy to design this type of architecture and it is a difficult job for designers.

Costly Hub: The hubs used to connect two distinct networks, are very expensive.

Costly Infrastructure: As hybrid architectures are usually larger in scale, they require a lot of cables; cooling systems, and sophisticated network devices.

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