论文部分内容阅读
IMS是3GPP组织在R5版本上提出的支持IP多媒体业务的子系统,它最显著的特点是采用了SIP协议。现在,UMTS系统中包含三个域:电路交换域,分组交换域和IMS。IMS必须和传统的电路交换用户如PSTN用户进行交互,这篇文章对电路交换域和IMS的互通作了探讨。文章首先简要介绍了IMS中用于互通的网络实体及其功能,然后分别从控制平面和用户平面描述了IMS用户和电路交换域用户的互通,最后给出了控制平面上的SIP协议和ISUP协议的映射。
IMS is a subsystem supported by the 3GPP organization on the R5 version to support IP multimedia services. The most prominent feature of SIP is its adoption of the SIP protocol. The UMTS system now contains three domains: circuit-switched domain, packet-switched domain and IMS. IMS must interact with traditional circuit-switched subscribers such as PSTN subscribers. This article explores the interworking of circuit-switched domains and IMS. The article first briefly introduces the network entities and their functions used for intercommunication in IMS, then describes the interworking between IMS users and circuit switched domain users from the control plane and user plane, and finally gives the SIP and ISUP protocols on the control plane The mapping.