Design And Implementation Of Ip-phone System Based On Sip Protocol

Voice over IP technology develops with the rapid development of network applications. And with the flourishing development of IP network broadband services in recent years, the text-based multimedia communication system standard SIP has got more and more extensive application in the video conference and VoIP services. The paper engaged to design and implement key problems of VoIP service based on SIP, which provides a strong support for VoIP.VoIP (so called IP telephone) communication controlling system mainly can be described as H.323 for ITU-T and SIP for IETF. SIP is an IP network multimedia communication signing protocol which is defined by the SIP work group of IETF. Cornparing with H.323, SIP has good extensibility, and is so simple that it is easy to implement. The prospect of SIP being applied in video communicaton is very fine.This thesis details functions, components, messages and structures of the system, and it involves user agent, proxy server, redirect server and directory server, etc. Under the LINUX environment, the system codes are compiled and are running suceessfull.The system works well when the network is busy. This system is now applied, gain the great economic benefits and launched to market.