Research And Implementation Of SIP Video Phone Based On IPv6

With the rapid development of network and multimedia technology,The VoIP technology has been widely applied in the Internet.Voip not only refers to IP telephone in narrow sense,but also refers to a comprehensive application platform which supplies real-time voice,video multimedia services.Present VoIP system generally are based on IPv4,but traditional IPv4 has some defects and limitations, IPv6 technologies is being built and developed,as a solution of these problems.How to transplant VoIP systems from IPv4 network to IPv6 network become a focus of relevant research domain.Furthermore,most of present VoIP systems in use are based on H.323 protocol,which conforms to the traditional design idea in communication fields,but doesn't suit for the opened and distributed Internet.SIP is proposed by IETF as a new signaling technology,which is conforming to Internet circumstance.Comparing to H.323 protocol,SIP has the advantage of easy implementation,high flexibility,scalability and mobility.SIP protocol and network developing under Ipv6 is researched in detail in this thesis.Video phone system based on SIP under IPv6 is designed and implemented. The main research contents of this dissertation are recapitulated as follows:1) VoIP architecture and character of IPv6 technology is introduced.And two VoIP signaling technology,H.323 and SIP protocol,are discussed and compared.2) The function structure,realization principle,message mechanism and signaling flow of SIP protocol are researched,and the implementation of the oSIP module parser and state-machine are analyzed based on oSIP open source.3) SOCKET programming technology is analyzed and solutions to the compatibility of application under IPv4 and IPv6 network.Finally,under Windows platform,video phone system based on SIP under IPv6 is designed and implemented, with oSIP2 and relevant protocols applied.This system can run over IPv6,the next generation of Internet protocol.It realizes the target of transplanting VoIP systems from IPv4 network to IPv6 network, so that VoIP system can take advantage of IPv6 on aspect of address capacity,quality of service and security,which make it more perfect and stable.Besides,SIP protocol is applied in this system,which is simpler and flexible,easier to expand,better mobility.The VoIP system supplier and operator can take this as reference,and supply diversified appreciation service more flexibly and conveniently.