Research And Design Of Internet Phone Prototype System Based On Pastry-c-sip

Internet phone, as a new optional communication tool, gets more and more attracted for its high quality, low price also and all kinds of added-value service. The development of Internet extends the using of VoIP, which is taking place of PSTN step by step.SIP gives the corporations more options.It can help corporations extricate themselves from the monopoly of PBX. Thus the corporations do not have to pay higher maintenance costs, buy expensive hardware, or suffer from private environment. SIP will be the promoter of network integration. SIP Internet telephony will dominants network telephone market. The situation has greatly changed since the introduction of SIP. But one thing has not changed: most enterprises are still the same like before, bounded tightly in the expensive back-end call server. P2P SIP is configured and installed more easily, and run with lower cost, through discarding the back-end demands.With P2P technology,SIP Internet phone system can fully make use of the end-point increasing computing capacity, also it can get rid of some shortage of the C/S(Client/Server) mode, which is popular nowadays. Such as not easy to extend the system, cause one point failure, lack of band during the hot access. So, the SIP Internet phone prototype system based on P2P is proposed.With the analysis of today main DHT-P2P resources positioning models,this thesis provides an improved resources, positioning models Pastry-C based on Pastry,which contains node joinning,route table updating,locating seed node and node finding.Then a simulation is made to contrast the performance with Pastry.With Pastry-C-SIP,the thesis designs the system and detailed modules.The thesis expands corresponding headfields for bearing P2P's properties through researching SIP.oSIP protocol stack is used to design SIP user agent and all kinds of SIP servers.And the corresponding oSIP protocol stack is modified and enlarged to implement new SIP messages and transaction handling with the consider of Pastry-C-SIP's propertities. Finally, the thesis implements the Pastry-C-SIP Internet phone prototype system.