为了使用令牌环访问方法通过局域网（LAN）实现数据处理设备的兼容互连，本标准 （1） 定义帧格式，包括分隔符、寻址、路由信息和帧检查序列（FCS），以允许在单个环上或通过源路由或透明网桥连接的多个环上进行操作，并引入媒体访问控制（MAC）帧、计时器、计数器和优先级堆栈（见第3节） （2） 定义MAC协议。有限状态机和状态表补充了算法的详细描述（见第4节）， （3） 定义符号编码和解码、符号定时和延迟缓冲的物理层（PHY）功能（见第5节）， （4） 描述MAC向站点管理（SMT）和逻辑链路控制子层（LLC）提供的服务，以及PHY向SMT和MAC提供的服务。这些服务是根据服务原语和相关参数定义的（参见第6节）， （5） 定义了4和16 Mh/s的屏蔽双绞线连接到 介质，包括介质接口连接器（MIC）的定义（见第7节）， （6） 包括符合相关要求和ISO 9646-2[7]中给出的相关指南的PICS形式表（见附录C）。

For the purpose of compatible interconnection of data processing equipment via a local area network (LAN) using the token ring access method, this standard (1) Defines the frame format, including delimiters, addressing, routing information, and frame-check sequence (FCS), to allow operation on a single ring or on multiple rings connected by source routing or transparent bridges, and introduces medium access control (MAC) frames, timers, counters, and priority stacks (see Section 3) (2) Defines the MAC protocol. The finite-state machine and state tables are supplemented with a prose description of the algorithms (see Section 4), (3) Defines the physical layer (PHY) functions of symbol encoding and decoding, symbol timing, and latency buffering (see Section 5), (4) Describes the services provided by the MAC to the station management (SMT) and the logical link control sublayer (LLC) and the services provided by the PHY to SMT and the MAC. These services are defined in terms of service primitives and associated parameters (see Section 6), (5) Defines the 4 and 16 Mh/s, shielded twisted pair attachment of the station to the medium including the definition of the medium interface connector (MIC) (see Section 7), (6) Includes the PICS proforma in compliance with the relevant requirements, and in accordance with the relevant guidance, given in ISO 9646-2 [7] (see Annex C).