ETSI TS 134 229-2-2008 全球移动通信系统(UMTS).基于会话初始协议(SIP)和会话描述协议(SDP)的互联网协议(IP)多媒体呼叫控制协议.第2部分:实现一致性声明(ICS)规范
Universal Mobile Telecommunications System (UMTS); Internet Protocol (IP) multimedia call control protocol based on Session Initiation Protocol (SIP) and Session Description Protocol (SDP); Part 2: Implementation Conformance Statement (ICS) specification