ICS 01.040.33 CCS M11 中 华 人 民 共 和 国 通 信行 业 标 准 YD/T XXXXXXXX—xxxx 路径计算单元通信协议技术要求 Technical specification for path computing element communication protocol (PCEP) （报批稿） YD 中华人民共和国工业和信息化部 发 布××××-××-××实施 ××××-××-××发布YD/T XXXXXXXX—xxxx I目次 前言 ...................................................................................................................................................................... III 1 范围 .................................................................................................................................................................... 1 2 规范性引用文件 ................................................................................................................................................ 1 3 术语和定义 ........................................................................................................................................................ 1 4 缩略语 ................................................................................................................................................................ 2 5 PCEP协议流程要求 .......................................................................................................................................... 2 5.1 通用流程要求 ............................................................................................................................................. 2 5.2 初始化阶段 ................................................................................................................................................. 3 5.3 会话保活阶段 ............................................................................................................................................. 3 5.4 PCC向PCE发送路径计算请求 ................................................................................................................ 4 5.5 PCE向PCC发送的路径计算应答 ............................................................................................................ 4 5.6 通知 ............................................................................................................................................................. 5 5.7 错误消息 ..................................................................................................................................................... 6 5.8 PCEP会话结束 ........................................................................................................................................... 7 5.9 临时 PCEP会话与永久 PCEP会话 .......................................................................................................... 7 6 传输协议要求 .................................................................................................................................................... 7 7 PCEP消息格式要求 .......................................................................................................................................... 7 7.1 PCEP消息格式说明 ................................................................................................................................... 7 7.2 公共头 ......................................................................................................................................................... 7 7.3 会话打开消息 Open Message ................................................................................................................... 8 7.4 会话保活消息 Keepalive message ............................................................................................................ 9 7.5 路径计算请求消息（ PCReq） ............................................................................................................... 10 7.6 路径计算响应消息（ PCRep） ............................................................................................................... 11 7.7 通知消息（ PCNtf） ................................................................................................................................ 12 7.8 错误消息（ PCE