ETSI TS 124 228-2002 数字蜂窝通信系统(第2+阶段).全球移动通信系统(UMTS).基于SIP和SDP的IP多媒体呼叫控制信令流.第3阶段.3GPP TS 24.228(版本5.2.0,第5次发布)
Digital Cellular Telecommunications System (Phase 2+); Universal Mobile Telecommunications System (UMTS); Signalling Flows for the IP Multimedia Call Control Based on SIP and SDP; Stage 3 3GPP TS 24.228 Version 5.2.0 Release 5