Research and Design of Interception and Control Model in Video Communication System Based on SIP

With the development of NGN which has SIP as the core protocol, there are more and more video communication services. It becomes focused on how to implement the interception and control in Video communication system based on SIP in real time. This article puts emphases on the character of SIP and the video communication system themselves and puts forward a design of the model. It uses the feature of media information´s interaction in signaling of SIP protocol during the media session establishment. At first, the model judges the communicating parties whether they are target users by analyzing the protocol. Then, it modifies the target users´ signaling information. So the model can access the communication parties´ media stream. And at the same time, the model uses the multi-modal media recognition technology. It uses the shunt to divide accessed media stream into audio and video stream. And it extracts audio, video and text information by analyzing them. Finally, the model uses these three modes to analysis the contained media content. Simulation results show that the model can not only implement the interception and control of the protocol but also recognize the content of media session effectively in real time.