Token Ring is a "token-passing" technology and an alternative to Ethernet's collision-detection method. Stations are connected in serial fashion around a ring. The stations pass a small frame called a "token" from station to station, giving each station in turn an opportunity to transmit data. Stations with no data to transmit simply pass the token to the next station. Stations that do have data to transmit replace the token with its data frame. When the transmission has been completed, the station generates a new token which it then passes to the next station in line. Individual Token Rings are interconnected with bridges. In recent years wire-speed Token Ring switches have replaced the original slow and expensive bridges, making more rings with fewer stations attached to each ring an economical alternative for Token Ring users.
Enterprise technologies from Cisco are based on Cisco AVVID --an open systems architecture that enables the deployment of innovative networked business solutions.
When to Use Token Ring
When bridges, server rings, and backbone rings are running out of capacity, you may choose to use Token Ring switching technology to upgrade your network infrastructure.
Cisco Token Ring technology provides you with the flexibility to gain immediate performance improvements in your existing Token Ring network while ideally positioning the network for migration to a modern, switched Ethernet network whenever that makes business sense. Second generation Token Ring switching solutions offer high performance, high functionality and low port price through:
- Full-duplex switched Token Ring
- Token Ring switching with a 100 Mbps or gigabit ISL backbone
- Token Ring switching with an ATM backbone
- Simultaneous Token Ring and Ethernet server and router attachment via ISL or ATM