WHAT ARE THE TYPES OF NETWORK TOPOLOGIES

NETWORK TOPOLOGY 

Network topology is the topological structure of a network and may be depicted physically or logically. It is an application of graph theory wherein communicationng devices are modeled as nodes and the connections between the devices are modeled as links or lines between the nodes. 

 

 Types Of Network Topologies

1. STAR TOPOLOGY 

A star network is an implementation of a spoke–hub distribution paradigm in computer networks. In a star network, every host is connected to a central hub. In its simplest form, one central hub acts as a conduit to transmit messages. The star network is one of the most common computer network topologies.

                                      Advantages 

•Very easy to connect a computer or peripheral to a linear bus.

•Requires less cable length than a star network resulting in lower costs.

• If one node or its connection breaks, it does not affect the other computers nor their connections

• Devices can be added or removed without disturbing the network

• Works well under heavy load

• Appropriate for a large network

Disadvantages 

• Expensive due to the number and length of cables needed to wire each host to the central hub

• The central hub is a single point of failure for the network

2. BUS TOPOLOGY 

bus topology is a network setup where each computer and network device is connected to a single cable or backbone. Depending on the type of computer network card, a coaxial cable or an RJ-45 network cable is used to connect them together

           

      Advantage    

• The linear architecture is very simple and reliable.

• It works well for small networks.

• It is easy to extend by joining cable with connector or repeater.

Disadvantages 

• Collisions occur in the network resulting in packet loss.

• Bandwidth is shared among nodes; Performance may degrade with many nodes on the network.

• It is difficult to isolate faults in the network.

• The entire network shuts down or is divided into two separate networks if there is a break in the main cable.

• If any link or segment of the bus is severed, depending on how the system has been designed, all network transmission may fail due to signal reflection caused by the lack of electrical termination.

3.RING TOPOLOGY 

A ring network is a network topology in which each node connects to exactly two other nodes, forming a single continuous pathway for signals through each node – a ring. Data travels from node to node, with each node along the way handling every packet.

Advantages 

•Very orderly network where every device has access to the token and the opportunity to transmit

•Performs better than a bus topology under heavy network load

•Does not require a central node to manage the connectivity between the computers

•Due to the point to point line configuration of devices with a device on either side (each device is connected to its immediate neighbor), it is quite easy to install and reconfigure since adding or removing a device requires moving just two connections.

•Point to point line configuration makes it easy to identify and isolate faults.

•Reconfiguration for line faults of bidirectional rings can be very fast, as switching happens at a high level, and thus the traffic does not require individual rerouting.

Disadvantages 

•One malfunctioning workstation can create problems for the entire network. This can be solved by using a dual ring or a switch that closes off the break.

•Moving, adding and changing the devices can affect the network

•Communication delay is directly proportional to number of nodes in the network

•Bandwidth is shared on all links between devices

•More difficult to configure than a Star: node adjunction = Ring shutdown and reconfiguration

4. MESH TOPOLOGY

A mesh network  is a local network topology in which the infrastructure nodes connect directly, dynamically and non-hierarchically to as many other nodes as possible and cooperate with one another to efficiently route data from/to clients.

Advantages

• •Each connection can carry its own data load
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• •It is robust
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• •A fault is diagnosed easily
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• •Provides security and privacy

Disadvantages 

• •Installation and configuration are difficult if the connectivity gets more
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• •Cabling cost is more and the most in case of a fully connected mesh topology
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• •Bulk wiring is required

5. HYBRID TOPOLOGY 

A combination of two or more topology is known as hybrid topology. For example a combination of star and mesh topology is known as hybrid topology.

Advantages 

•We can choose the topology based on the requirement for example, scalability is our concern then we can use star topology instead of bus technology.

•Scalable as we can further connect other computer networks with the existing networks with different topologies.

  Disadvantages

•Fault detection is difficult.

•Installation is difficult.

•Design is complex so maintenance is high thus expensive.