The Design And Implementation Of Multipoint Video Conferencing System On Campus Network

Owing to the progress of computer network technologyi multimedia technology and communication technology, the development and application of Video Conference technology become the hotspot of network technology. The two organization including ITU and IETF had offered their network multimedia framework respectively. It is possible to transfer multimedia in digital channel because of the development of fast compression technology and the establishment of some related standard protocol. Many campuses had finished the upgrade of old network and realized "Trunk kilo-mega, desktop hundred-mega" at present., So it is our now important mission how to utilize the wide bandwidth of campus network offering abundant multimedia application in addition to the high quality traditional network service to serve our teaching and scientific research.The digital construction of campus network includes two independent but tightly cooperative sections, which are real time video interactive system and multimedia interactive teaching platform . This article mainly focuses on the resolution of the construction of multi-point videoconference in campus network.This article abides by the standard of H.323 multi-point video conference, combines with the RTP/RTCP protocol of IETF and puts forward an interactive video conference system in IP multicasting context by pure software. This system has a good expansibility and it is easily regulated. QoS module has been added into the system, system terminal has a good adaptability. It can offer an economic practicable video system, so it is suitable for learning conference and learning discussion in campus network.Much work has been done in this paper:1. It analyzes the advantage and the disadvantage of the distribute multi-point video conference system based on H.323, and forwards a system resolution combined with RTP and RTCP of IETF based on the characteristic of campus network video conference.2. It introduces the network technology, multimedia technology and program toolsuitable for this system, This article gives a detailed analyse mainly on the multicast technology and RTCP datagram.3. The software realization of RTP/RTCP protocol and multimedia data transfer.4. The software developments of multicast communication are also discussed.5. It designs QoS module and conference management module.6. The multimedia underlying software developments including sound and video stream capture, compression and decompression and playback of the stream in windows system.