Research On The Multimedia Application Of Next Generation Network

With the development of computer technology and communication, it is recognized by more and more device manufacturers and operators that the voice, data and video should be carried on a public-group network. Because of the trends of business-driven and network integration, the next generation network model is born. NGN is realized through a group network, distributed network structure is used and multimedia data is effectively carried.The technologies of multimedia communication over NGN are discussed in the paper, a video phone system based SIP is realized as well. Firstly, NGN architecture and core technologies are discussed, the system of NGN protocol is analyzed also. Through all kinds of protocols used to control connection are compared, the advantages and disadvantages of them are shown and analyzed. The best, SIP and RTP/RTCP, is selected. Soft Switch and SIP that is mainstream application protocol in NGN are studied. The structure of SIP message and process of building connection are introduced, a SIP stack model is set to program. Beside the protocol of connection control, other technologies such as Stream media technology, video and audio codec, NAT Traversal etc which related with the application are mentioned in the paper also. Secondly, based what are mentioned above, a video over IP phone meeting system is introduced which shows how these technologies organized together to realize the system. This system is timely, stable and friendly. It is welcomed by all users. At last, a typical model of NGN multimedia application is introduced in the back of paper. Because VOIP system is a typical application over NGN, this typical application model over NGN can be referred to by the other applications over NGN in future.