Description of Fasnet — A unidirectional local-area communications network

Fasnet is an implicit token-passing, local-area network aimed at supporting high data rates and carrying a wide mix of traffic (data, voice, video, and facsimile). Transmission is unidirectional with stations attaching to the medium passively via directional couplers. A link consists of two lines, one to carry traffic in each direction. Unidirectional transmission provides the potential for efficient operation at high data rates, while the passive medium provides the potential for high reliability. We describe the physical configuration and the protocol and give channel utilization for the condition of continuously queued sources. Mechanisms to control the access of various traffic types are described. Finally, the interconnection of multiple Fasnets is studied for one particular configuration, a ring.