A copper version of FDDI which uses category 5 cable. Obviously the distance is more limited than FDDI.
Copper Distributed Data Interface
Copper Distributed Data Interface. Implementation of FDDI protocols over STP and UTP cabling. CDDI transmits over relatively short distance (about 100 meters), providing data rates of 100Mbps using a dual-ring architecture to provide redundancy. Based on the ANSI Twisted-Pair Physical Medium Dependent (TPPMD) standard.