本文件包含基于建议ITU-T Q.543[1]的适用于IMS/PES/电压交换实施的设计要求。IMS/PES/VoLTE设计目标的定义基于传统PSTN/ISDN信令的“最佳实践”性能。本文件中包含的值是在IMS和NGN实施中测量的“最佳实践”性能值。ISDN VGW值基于载波级实现。先决条件的处理超出了本文件的范围。

The present document contains design requirements applicable to IMS/PES/VoLTE exchange implementations based on Recommendation ITU-T Q.543 [1]. The definitions of IMS/PES/VoLTE design objectives are based on "best practice" performance of legacy PSTN/ISDN signalling. The values contained in the present document are "best practice" performance values measured on IMS and NGN implementations. The ISDN VGW values are based on carrier grade implementations.The handling of preconditions is out of the scope of the present document.