In this topology, all hosts are connected in closed loop manner. Each node in this topology is connected to its adjacent two nodes in a ring like formation. Adjacent nodes are directly connected with each other, while non adjacent nodes are indirectly connected.
Following is illustration of Ring topology
We see node A is connected directly to its two adjacent nodes B and D, while there is no direct connection between host A and C but still they can communicate with each other via indirect links that goes from host B.
Ring topologies are implemented using Token ring mechanism. In which host holding ‘Token’ can only send data, token is released by sender upon receipt of data transfer. This prevents data collision as only one hosts holding ‘Token’ can send the data, while remaining hosts waits for the token to be released.
Advantages associated with Token ring topology are
Less expensive implementation
As every host is connected to its adjacent two nodes, there is no need for expensive central Layer 2 or 3 devices to control overall operation of the network, this results in reduction of overall cost for implementing topology.
Adding new host in this topology will be easy, as it needs to be connected with its two adjacent nodes only. This topology is good choice for networks that are subject to expansion in near future.
Data in this topology can only travel in one direction; this eliminates the chances of data collision.
Next we see disadvantages associated with Token ring topology are
In ring topology, data has to travel every device before reaching its destination. For example, in above diagram if host A wants to send data to host C, it has to move through host B to reach host C. In this case there is only one hosts in between sender and receiver, hosts may increase depending upon size of network. As we have more devices added in the network, speed of network will go down. Keep in mind this factor before you opt for this topology
Single point of Failure
As it’s a famous saying, a chain is as strong as its weakest link, same is true here. This network will go down if any one of its hosts goes down. For instance, if host C in above diagram goes down, host A and B cant communicate to host C and D.