Research And Realization On SIP Based Multi-media Conference System In NGN Networks

The multi-media conference application in the traditional telecom network is mainly based on H.320 or H.323 criterion. Its complex realization mechanisim and costly investment make it difficult to be applied in public. On the other hand, the close architechture and low bandwidth of the traditional telecom network are not suitable for the fast development and deployment on multimedia applications, which can not meet the bandwidth requirements of mass multi-media users yet. Thus a new technology and a new network need to be brought forward to meet the multi-media conference applications requirements of the common persons. The new techonogy is SIP (Session Initiation Protocol), which is brought forward by IETF, based on Internet and has the inherent flexibility, openness and scalability. The new network must be NGN (Next Generation Network), which is combined by the good aspects of traditional telecom network and Internet network. The core idea of NGN is based on broadband IP QoS network and open layered network architechture to provide abundant multi-media applications for end users. SIP is naturally in harmony with NGN and it is one of the most important session control protocols in NGN network. SIP based multi-media conference system can meet the multi-media session requirements in NGN easily. In the meantime, it has the good capability of system scale extending and can provide the end users more convenient conference mutual function. Through the in-depth analysis of SIP conference mixing model and tightly coupled conference framework model provided by IETF, this paper bring forward a SIP conference model suitable for NGN network, i.e. a separated model of conference control function, media mixing function and end users mutual function. Based on this model, this paper illustrates the construction and design way of an actual multi-media conference system, i.e. a Web based multi-party voice chat room system. The system...