Short for Fiber Distributed Data Interface, FDDI is a standard developed by the American National Standards Institute (ANSI) for transmitting data on optical fiber cables. FDDI supports transmission rates of 100 megabits per second on token-passing networks.
FDDI-2 or FDDI II is an extension of FDDI that contains additional specifications for real-time transmission of analog data in digitized form. This transmission could be used for digitized sound.
FFDT, an acronym of FDDI Full Duplex Transmission, is patented by Digital. FFDT is an extension of FDDI that is capable of supporting up to 200 Mbps, or twice the speed of the original FDDI.