Copper Data Distribution Interface (CDDI)

The logical topology used in CDDI is a ring-based token network. CDDI does not use the IEEE 802.5 Token Ring Protocol, but derives from the IEEE 802.4 Token Bus Timed Token Protocol. This network can support thousands of users or terminals as well as cover a wide geographical area.

CDDI is not widely applied due to the decrease in the price of fiber optic installation, which has greater efficiency, a much higher bandwidth and an immunity to interference. Data transfer in CDDI has a throughput of 100 Mbps when using a redundancy architecture.

CDDI is the same networking system as FDDI, although the medium for the transmission is copper twisted-pair wire instead of fiber optic cables. Copper cables are no longer widely used because they can only stretch as far as 100 meters, compared to 1,000 meters for fiber optic cables. CDDI is commonly implemented in a wide geographical area.