The media access control characteristics for the Demand Priority access method are specified. The layer management, physical layers, and media that support this access method are also specified. Layer and sublayer interface specifications are aligned to the ISO Open Systems Interconnection Basic Reference Model and ISO/IEC 8802 models. Specifications for 100 Mb/s operation over 100 = balanced cable (twisted-pair) category 3 through 5, 150 = shielded balanced cable, and fibre optic media are included.

This standard defines the protocol and compatible interconnection of data communication equipment via a repeater-controlled, star-topology Local Area Network (LAN) using the demand-priority access method.

The purpose of this protocol is to provide a higher speed LAN with deterministic access, priority, and optional filtering. Pursuant to this, the protocol will: a) Provide a minimum data rate of 100 Mb/s.; b) Provide smooth migration from ISO/IEC 8802-3 and ISO/IEC 8802-5 LANs.; c) Support either ISO/IEC 8802-3 or ISO/IEC 8802-5 frame format and MAC service interface to the LLC.; d) Support a cascaded star topology over twisted pair and fibre optic generic building wiring.; e) Allow topologies of 2.5 km and greater with 3 levels of cascading.; f) Provide a Physical Layer Bit Error Rate (BER) of less than 108.; g) Provide fair access and bounded latency.; h) P...