本标准提供了单模光纤同步光网络（SONET）网络至客户安装接口的物理介质相关（PMD）规范。给出了与网络接口（NI）相关的标准速率标准。本文涵盖的标准包括SONET（PMD）标准（如光学参数和连接器），以及符合NI光学规范和连接客户安装设备正确接口的其他必要标准。遵守本标准旨在确保SONET NI的兼容性，不应被视为对网络或客户安装设备内部操作的限制。

This standard provides Physical Media Dependent (PMD) specifications for Single Mode Fiber Synchronous Optical NETwork (SONET) network to customer installation interfaces. Criteria is given for standard rates associated with the Network Interface (NI). Criteria covered herein include SONET (PMD) criteria (such as optical parameters and connectors), and other necessary criteria for compliance with the optical specification at the NI and the proper interfacing of the connecting customer installation equipment. Compliance with this standard is intended to ensure compatibility at the SONET NI and should not be construed as a constraint on the internal operations of the network or customer installation equipment.