Ring Topologies

Ring Topologies

Ring topologies are wired in a circle. Each node is connected to its neighbors on either side, and data passes around the ring in one direction only (see Figure 4.5). Each device incorporates a receiver and a transmitter and serves as a repeater that passes the signal on to the next device in the ring. Because the signal is regenerated at each device, signal degeneration is low.

Ring topologies are ideally suited for token-passing access methods. The token passes around the ring, and only the node that holds the token can transmit data.

Ring physical topologies are quite rare. The ring topology is almost always implemented as a logical topology. Token Ring, for example—the most widespread token-passing network—always arranges the nodes in a physical star (with all nodes connecting to a central hub) but passes data in a logical ring (see Figure 4.6).

You get a closer look at Token Ring later in this chapter in the section titled “Token Ring.”