Design And Realization Of IP Video Telephone Software Based On LAN

Voice over IP (VoIP) technology is a new technology developed in recent years. The VoIP technology has many advantages such as narrow bandwidth occupied, high efficiencies of resource utilized, and low cost. Because the VoIP technology can realize real-time voice transferring over IP network, it has been widely applied to all over the world, and popularized at a large area in China. The technology can be applied to not only wide area network (WAN), but also PC-to-PC video telephone for the enterprise users of local area network (LAN). It can make the best of the resources in existence, and realize the sake of saving money. At first, in this paper the background and basic principle of VoIP are introduced; the much popular VoIP technology based on H.323 protocol is studied; based on the function and main working process of IP telephone system, the principle of coding of compression and transfer technology of the real-time voice are analyzed; depended on the existed experimental environment, the program of voice part of PC to PC video telephone terminal based on LAN is designed and implemented; and the problems encountered during the design of program have been analyzed and solved. Our experiment has proved that realization of VoIP based on the present LAN is feasible, and that the VoIP can not only save bandwidth and cost, but also fully dig the potential of present resources. Besides, these problems that are necessary to be resolved such as audio and video synchronization and enhancement of the real-time voice quality of IP telephone are explored. At last, this paper prospects the future of the VoIP technology.