The Token Ring standards are defined in IEEE 802.5. It is a prime example of an architecture whose physical topology is different from its logical topology. The Token Ring topology is referred to as a star-wired ring because the outer appearance of the network design is a star. The computers connect to a central hub, called a Multistation Access Unit (MSAU). Inside the device, however, the wiring forms a circular data path, creating a logical ring.

Token Ring is so named because of its logical topology and its media access control method of token passing. The transfer rate for Token Ring can be either 4 Mbps or 16 Mbps.

Token Ring is a baseband architecture that uses digital signaling. In that way it resembles Ethernet, but the communication process is quite different in many respects. Token Ring is an active topology. As the signal travels around the circle to each network card, it is regenerated before being sent on its way.

In an Ethernet network, all computers are created physically equal. At the software level, some may act as servers and control network accounts and access, but the servers communicate physically on the network in exactly the same way as the clients.

The Monitor of the Ring
In a Token Ring network, the first computer that comes online becomes the "hall monitor" and must keep track of how many times each frame circles the ring. It has the responsibility of ensuring that only one token is out on the network at a time.

The monitor computer periodically sends a signal called a beacon, which circulates around the ring. Each computer on the network looks for the beacon. If a computer does not receive the beacon from its Nearest Active Upstream Neighbor (NAUN) when expected, it puts a message on the network. The message notifies the monitoring computer that the beacon was not received, along with its own address and that of the NAUN that failed to send when expected. In most cases, this will cause an automatic reconfiguration that restores communications.

Data Transfer
A Token Ring network uses a token (that is, a special signal) to control access to the cable. A token is initially generated when the first computer on the network comes online. When a computer wants to transmit, it waits for and then takes control of the token when it comes its way. The token can travel in either direction around the ring, but only in one direction at a time. The hardware configuration determines the direction of travel.