Research On SIP VideoConference System Based On Softswitch

With the appearance of new requirement and the advancement of technology, Next-Generation-Network (NGN) and NGN-based Value Added System(VAS) become the research hotspot of computer and communication. Softswitch and Parlay are the representative technologies in the field. They can realize the separation of application logic and switch control. So they become the ideal platform for new type VAS.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.With the development of next generation network (NGN),softswitch,Sip,it is easy to design and implement a multi-media conference system that has the high using rate of resource, and it is easy to extend.On the basis of studying the traditional multi-media conference system, it's key technologies, Softswitch, NGN network frame and the SIP protocol, this paper proposes a project of NGN multimedia conference based on SIP protocol. This paper will first introduce the architecture and advantage of NGN, the theory of Softswitch, then analyze the theory of interaction and communication flow of Parlay platform and Parlaybased application. Meanwhile, at the requirement of a recent telecom hotspot—videoconference. This paper bring forward a Parlay-based iWeSee model, and then discuss the whole design process of iWeSee, especially go deep into the subscriber management sysytem, iWeSee media process system, Parlay GW system and Video-conference terminal system.Finally, we take the example of iWeSee deployment in Shanghai SHENGDA project.and illustrate a realization of iWeSee in a real telecom operation environment, then give the results include functional test and performance test. We summarize the advantage and latent of iWeSee, point out the research and development way in futhure.