Research, Design And Realization Of The Technologies Of P2P-SIP Key Technologies

P2P(Peer-to-Peer) technology is very popular in Internet nowadays and get a great success in file-sharing, distributed calculation, distributed storage and so on.P2P shows explicit advantage on non-centralization, expansibility, reliability and load balancing etc., which make up the limitation of the traditional Client/Server(C/S) architecture. Meantime the current C/S model VoIP system based on SIP(session initiation protocol) gradually also shows the same problem as more and more users coming to the system and the limitation of the expansibility, reliability, security and load-balancing will become bigger. The P2P-SIP technology,born from the thought of the combination of P2P and SIP, can get a convergence of the both advantages to solve the problem just talked about. Under the background, the thesis does a research on P2P-SIP.The key problem of P2P-SIP is how to achieve a simple and highly maintainable way to add P2P module into our current VoIP system. The thesis firstly defines the P2P's function in SIP entity that using P2P distributed characteristic to realize the distributed storage and lookup of the user information instead of the traditional DNS(Domain Name Server) method. Then the differences between structured and unstructured and that between VoIP-using-P2P and P2P-over-SIP are both discussed. P2P-over-SIP is fianaly selected to build the P2P-SIP node. The DHT(Distribute-Hash-Table) algorithms is very important in the design plan. After analyzing classic P2P DHT algorithm and the situation of the rencent application of DHT algorithm, the method that adding kad into SIP node is firstly put farwords, and the solution of NAT traversing, QoS( Qaulity of Service),security reputation mechanism etc are also discussed.After finishing the P2P-SIP principle design,the thesis put forward the heterogeneous network model of the P2P-SIP system under the whole system level. We develop the DHT DLL(Dynamic Link Library) and use the DLL to build the Proxy Peer, the SBC(Session Border Controller) Peer, and the UA(User Agent) Peer. Additionally, the P2P-AVS(P2P Anti-Voice-Spam) security reputation mechanism is added into the Proxy Peer node. Finally, the simulation of the Kademlia DHT and the testing of the Proxy Peer combination performance are both carried out. Its result shows the feasibility of P2P-SIP technology.