中 华 人 民 共 和 国 通 信 行 业 标 准 光业务单元（ OSU）技术要求 Technical requirements for Optical Service Unit (OSU) （报批稿） ICS 33.040.20 CCS M 33 YD YD/T XXXX—XXXX XXXX- - XX - XX发布 XXXX - XX - XX实施 中华人民共和国工业和信息化部 发布 YD/T XXXX-202X II 目 次 前 言 ................................................................................... IV 1 范围 .................................................................................. 5 2 规范性引用文件 ........................................................................ 5 3 术语定义 .............................................................................. 5 4 缩略语 ................................................................................ 6 5 OSU层网络架构 ......................................................................... 9 5.1 OSU层网络概述 ..................................................................... 9 5.2 信息结构 .......................................................................... 9 5.3 复用层次 .......................................................................... 9 5.4 功能要求 ......................................................................... 10 6 OSU功能结构 .......................................................................... 10 6.1 OSU帧结构 ........................................................................ 10 6.2 OSU通用开销 ...................................................................... 11 6.3 OSU映射开销 ...................................................................... 18 6.4 OSU帧类型 ........................................................................ 18 7 OSU比特率 ............................................................................ 24 7.1 基准速率 ......................................................................... 24 7.2 比特速率 ......................................................................... 24 8 客户信号映射到 OSU .................................................................... 26 8.1 以太网映射 ....................................................................... 26 8.2 CBR映射 .......................................................................... 34 8.3 PRBS测试信号映射 ................................................................. 41 9 OSU复用 .............................................................................. 41 9.1 OPU PB结构 ....................................................................... 41 9.2 传送周期和 P值 ................................................................... 42 9.3 OSTU ............................................................................. 43 9.4 IDLE速率适配 ..................................................................... 43 9.5 OSU复用到OPU .................................................................... 44 10 OSU无损带宽调整 ...................................................................... 47 10.1 无损带宽调整功能要求 ........................................................... 47 10.2 带宽调整 OAM帧 ................................................................. 47 11 OSU保护 .............................................................................. 48 11.1 保护概述 ....................................................................... 48 11.2 OSU SNCP 1+1保护 ................................................................. 48 11.3 保护倒换协议 ................................................................... 50 12 OSU时钟同步 .......................................................................... 50 12.1 概述 ........................................................................... 50 12.2 物理层时钟同步 ................................................................. 51 12.3 自适应时钟同步（可选） ......................................................... 51 III附　录　A （资料性） OSU单帧模式穿通复帧模式组网场景 ..................................... 53 A.1 通用描述 ........................................................................... 53 A.2 穿通场景 ........................................................................... 53 A.3 穿通组网节点要求 .....................................