Fiber Distributed Data Interface (FDDI) is an architecture that provides high-speed network backbones that can be used to connect and extend the range of LANs. FDDI uses fiber-optic cable and is wired in a ring topology. FDDI uses token passing as its media-access method and can operate high speeds (most implementations are 100Mbps, but faster data-transfer rates are possible).

   FDDI does not have an IEEE specification but rather has a designation of ANSI X3T9.5, which has been formulated by the American National Standards Institute (ANSI). Because FDDI uses a token-passing media-access strategy, it is considered reliable and provides equal access to all computers on a network. With FDDI, however, you can set priority levels, which means you can designate that servers be allowed to send data more often over the network than client computers.