In a ring topology each network device is connected to two others to form as part of a closed loop. The most common cable type used when constructing a ring topology network today is unshielded twisted pair using token ring.
Token ring can be used over shielded or unshielded twisted pair. Typically, older installations used shielded twisted pair. Newer installations can take advantage of unshielded twisted pair.
When a network device on a ring topology network wants to communicate, they need to control the token. The token is used to communicate information on the network. Think of the token like an empty postal package. When a network device wants to communicate it needs to wait for the token, fill the token and address it. The token is then passed from network device to network device until the destination device is found. When the destination device is found, the information is read and the token is released. There is only one token on the network, so network collisions are minimized.
Ring Topology Advantages
Ring topology networks have several advantages:
Cleaner network traffic: Since communication is based on token passing, the network data moves through the network in a more efficient manner with fewer collisions.
Easier troubleshooting: When an error is detected in a ring topology the downstream network clients will not function. You can easily identify the network client that is causing the error.
High transmission speeds: Ring topologies can support higher transmission speeds than other topologies.
Ring Topology Disadvantages
Ring topology networks have several disadvantages:
Expensive: Ring topology based networks are not as popular as bus or star topologies, so the equipment to provide the infrastructure is more expensive.
Transmission delays: Depending on the network clients attached to the ring topology network, transmission delays can occur if the token is not passed properly.