光纤分布式数据接口（FDDI），ISO/IEC 9314，旨在用于高性能 通用多节点网络，设计用于峰值数据速率为 100Mbit/s。它采用令牌环结构，光纤作为传输介质。FDDI 提供了数百个在数十公里范围内运行的节点。 物理层协议（PHY）指定用于FDDI的物理层的上子层。像 因此，它介绍了为符合FDDI连接设备提供的规范和服务。 PHY规定了数据编码和解码、成帧和时钟要求。 PHY还规定 弹性缓冲、平滑和重复滤波功能。用于PHY-2的ISO/IEC 9314的这一部分是对PHY上的原始FDDI标准的增强 （ISO 9314-1）。

The Fibre Distributed Data Interface (FDDI), ISO/IEC 9314, is intended for use in a high-performance general purpose multi-node network and is designed for efficient operation with a peak data rate of 100 Mbit/s. It uses a Token Ring architecture with optical fibre as the transmission medium. FDDI provides for hundreds of nodes operating over an extent of tens of kilometers. The Physical Layer Protocol (PHY) specifies the upper sublayer of the Physical Layer for the FDDI. As such, it presents the specifications and services provided for conforming FDDI attachment devices. PHY specifies the data encode and decode, framing, and clocking requirements. PHY also specifies the elasticity buffer, smoothing, and repeat filter functions. This part of ISO/IEC 9314 for PHY-2 is an enhancement to the original FDDI standard on PHY (ISO 9314-1).