Design And Implementation Of Sip-Based Video Conferencing System

With the development of network technology, the traditional video, audio, data and other communication contents are migrated to the Internet, the low-cost, highly flexible transmission on it has become one of the developments of today’s communications. The Internet has exceeded the fixed terminal stage, forward continuous development of the direction of fixed mobile convergence and the three networks (telecom networks, radio networks, the Internet) convergence. SIP (Session Initiation Protocol) which is responsible for the drafting of the Internet multimedia session control protocol by the IETF (Internet Engineering Task Force), can overcome complexity and limitations of the H.323protocol, which is developed by the ITU-T (ITU Telecommunication Standardization Sector), and it is more suitable flexible, a wide range of applications on the Internet. It is for this reason,3GPP (3rd Generation Partnership Project) make SIP as the core of the next generation of network control protocol. In this context, the research design and implementation of SIP-based video conferencing systems has important significance.This paper introduces the SIP and related knowledge, common way for today’s network multimedia transmission and their advantages and disadvantages, and then proposed a distributed media transmit strategy to effectively overcome the problems of real-time poor, network load imbalance. Then, design the framework and sub-module of conferencing systems, and to implement it through the Java program and JMF framework.Distributed video conferencing strategy process is as follows. First, transmit the control messages through the SIP terminal or conference control center, to get the terminal of media transport address. Second, the video terminals, which send video, need transmit own terminal generates respective portion of the data packets to the respective receiving terminal according to the algorithm requires. Third, received data packets are respectively transmitted to the other receiving terminals. Thus, as long as the receiving terminals has processing media capabilities, which can afford to send part of the data packages, the system can improve the real-time conferencing systems, and further reduce the network load, conducive to the balanced development of the entire network.