GB/T 16678.2-1996 in English

《GB/T 16678.2-1996信息处理系统 光纤分布式数据接口（FDDI） 第2部分:令牌环媒体访问控制（MAC）》由TC28（全国信息技术标准化技术委员会）归口，TC28SC25（全国信息技术标准化技术委员会信息技术设备互连分会）执行，主管部门为国家标准化管理委员会。
本标准为光纤分布式数据接口(FDDI)规定了媒体访问控制(MAC),即数据链路层(DLL)的较低子层。

Scope

This standard specifies the Media Access Control (MAC), the lower sublayer of the Data Link Layer (DLL), for the Fiber Distributed Data Interface (FDDI). FDDI uses optical fiber as the transmission medium to provide a high-bandwidth (100Mbit/s) general-purpose interconnection between computers and peripheral devices. FDDI can be configured to support a sustained transfer rate of approximately 80Mbit/s (10Mbyte/s). It may not meet the response time requirements of all unbuffered high-speed devices. FDDI establishes connections between many stations spread over several kilometers. The default value of FDDI is based on 1000 physical links and an optical fiber path with a total length of 200Km (typically corresponding to 500 stations and 100Km of dual optical cables). FDDI consists of the following parts: Physical layer (PL), which provides media, connectors, optical bypasses and drive/receive devices. The physical layer also defines the encoding/decoding and clocking requirements required for framing data during media transmission or sending to the FDDI upper layer. For the purposes of this standard, references to PL are made through the physical layer entity specified by the PHY. Data Link Layer (DLL), divided into two sublayers: Media Access Control (MAC), which provides fair and deterministic access to the media, address identification, and generation and verification of frame inspection sequences. Its main function is to implement frame Transmitting, including insertion, relay, and removal of frames. The definition of MAC is given in this standard. Logical Link Control (LLC), which provides the common protocol required for error-free data services between the MAC and network layers. Station Management (SMT) ¹⁾, which provides the necessary control at the station level to manage processes in the various FDDI layers so that stations can work in harmony on the Token Ring. SMT provides services such as station initialization control, configuration management, fault isolation and recovery, and process scheduling. The MAC definitions included in the standard are designed to be as independent as possible from the transmission medium and the rate of operation. In order to adapt to the higher rate of FDDI, while modifying GB AAAA's related concepts about token ring MAC operations, it retains similar services and facilities. This series of standards specifies the interfaces, functions, and operations necessary to ensure interoperability between FDDI-compliant implementations. This standard is a functional description to which conforming implementations may utilize any design technique that does not violate interoperability