Describes the Media Access Control (MAC), the lower sublayer of the Data Link Layer (DLL), for Fibre Distributed Data Interface (FDDI). Intended for use in a high-performance multistation network with the protocol designed to be effective at 100 Mbit/s using a Token ring architecture and fibre optics as transmission medium over distance of several kilometers in extent. References: ISO 8802-2; 8802-5; 9314-1; 9314-3.