Types of Network Topology – The physical arrangement of computers in a network is called as topology. There name of topologies are : Star Topology, Ring Topology, Bus Topology, Mesh Topology, Hybrid Topology, Tree Topology and so on.

Types of Network Topology

1	Star Topology
2	Ring Topology
3	Bus Topology
4	Mesh Topology
5	Hybrid Topology
6	Tree Topology

Star Topology

In this type of topology all the computers are connected to a single hub through a cable. This hub is the central node and all others nodes are connected to the central node. Out of many Types of Network Topology, this is first one.

Merits Of Star Topology

• Cheaper media of Networking.
• Less number of Cables required.
• Transmission delays between two nodes do not increase by adding new nodes to the network.
• If any node fail, the remaining portion of the network is unaffected.
• Easy to add new nodes.

Demerits Of Star Topology

• The hub offers limited number of connections.
• If hub fails, the entire network fails.
• The cabling cost is more since cables must be pulled from all computers to the central hub.
• Many star networks require a device at the central point to rebroadcost or switch the network traffic.

Ring Topology

It is called ring topology because it forms a ring as each computer is connected to another computer, with the last one connected to the first. Exactly two neighbours for each device.

Merits Of Ring Topology

• It is a True Distributed Data processing system.
• More reliable than STAR because communication is not dependent on Hub.
• In ring topology, a shorter cable length is needed as compared to star topology.
• Ring topology delivers fast and efficient performance.
• It is suitable to setup high speed network using optical fibers.

Demerits Of Ring Topology

• Addition of New Node increases the communication delays.
• Complicated control software.
• In the ring topology, the failure of a node causes failure in the network.
• As the single channel is shared by various nodes, it is difficult to diagnose the fault.
• It is difficult to add, remove or reconfigure the nodes in the network.

Bus Topology

Out of many Types of Network Topology, this is third. Bus topology is a network type in which every computer and network device is connected to single cable. When it has exactly two endpoints, then it is called Linear Bus topology. 

Merits Of Bus Topology

• Less number of cable required.
• Easy to expand.
• Nodes can be added without distributing the rest of network.
• Easy to understand and install.

Demerits Of Bus Topology

• If the communication line fails, the entire system breaks down.
• It is very difficult to repair the fault in this topology.

Mesh Topology

It is a point-to-point connection to other nodes or devices. All the network nodes are connected to each other. Mesh has n(n-1)/2 physical channels to link n devices. Out of many Types of Network Topology, this is fourth.

Merits Of Mesh Topology

• Reduction in total physical Lines.
• Reliability is high.
• Addition of new nodes is easy.
• Failure of any node does not affect the network functioning for other computer.

Demerits Of Mesh Topology

• If line fails, entire system breaks down.
• Each node must have good &quick decision making capability.

Hybrid Topology

It is two different types of topologies which is a mixture of two or more topologies. For example if in an office in one department ring topology is used and in another star topology is used, connecting these topologies will result in Hybrid Topology (ring topology and star topology).

Tree Topology

It has a root node and all other nodes are connected to it forming a hierarchy. It is also called hierarchical topology. It should at least have three levels to the hierarchy.

Merits Of Tree Topology

• The controlling and control software are very simple.
• A new node at lowest levels can be added very easily.

Demerits Of Tree Topology

• If top most computer fails it may lead to failure of entire network.
• If a new node is to be added at higher levels it is very difficult.
• If the levels increase it may lead to a complex network.