In a ring topology, the computers are connected by a single ring-shaped cable. Unlike the bus topology, there are no terminated ends. The signals are transmitted in the loop in one direction and forwarded via each computer. Each computer serves as a repeater to amplify the signal and send it to the next computer. In larger systems, several LANs can be interconnected in a ring topology. ThickNet coaxial cables or fiber optic cables were used for this purpose.
The advantage of a ring topology is that each computer serves as a repeater, re-generating the signal and forwarding it to the next computer, maintaining signal strength.
The method of transferring data in the ring structure is called token passing. A token is a special sequence of bits containing control information. Owning the token allows a network device to transfer data to the network. There is only one token in each network.
The sending computer removes the token from the ring and sends the requested data in the ring. Each computer forwards the data until the packet finds the computer that matches the data address. The receiving computer then sends a message that the data has been received back to the sending computer. After verification, the sending computer creates a new token and releases it to the network.
The advantage of a ring topology is that it is more suitable for high traffic environments than bus networks. It also mitigates the effects of noise in the ring topology.
The disadvantage of a ring topology is that only one computer at a time can send data in a single token ring. In addition, ring topologies are usually more expensive than bus technologies.