What is Ring Topology

The ring topology connects the nodes on a network through a point to poinr connection. Consequently, no end points exist in this type of setup.
The following figure shows a typical ring-based setup.

In the preceding figure all computers are connected in  a ring-like layout.As a result,similar to the bus topology, the main cable is the only transmission path.How ever, unlike the bus topology, data packet can ravers only in a unidirectional format.
When a node receives a data packet ,it reads the data packet and regenerates it to restore its original strength. The packet is then passed to the neighboring node. The data packet navigates the network in this format until the destination nodes receives the packet.

Advantages

Prevention of Collisions

The ring topology prevents network collisions by using the token ring access method. According to this method, if a node needs to transmit data, it must acquire a token that circulate through the ring. when the node acquire the token ,the node uses the token to transfer its data to the destination node. Until the current node releases the token other node cannot transmit data and must wait for their turn to acquire the token. As a result, the possibility of any collision in this step is 0.

Ease in troubleshooting and maintenance

Its easy to locate cable faults in ring setup.In cable related fault, the nodes that is next to failed cable segment can indicate the fault when it fails to receive a signal within the specified time limit.

Limitations

High Risk of network Failure

On a ring network, the nodes are connected through a point to point connection. If one of node on the network malfunctions , the entire network stops functioning.

Expensive Setup and Installation

The Device and Cabling  required to setup a ring network are more expensive than any other topology.