Research Andapplication Of SIP System Based On P2P

The SIP (Session Initiation Protocol) is one of the most important protocols in the area of VoIP, but existing SIP systems are configured and maintained by hand, and its scalability is limited. With the maturation of P2P technology, there is a trend to transfer P2P (Peer-to-Peer) concepts to SIP. JXTA is an open P2P platform, which provides basic infrastructure services for building P2P applications. After a thorough study on JXTA network with decentralized structured network, a P2PSIP system is designed and implemented which is able to maintain the SIP communication without central servers.First, this thesis gives an introduction of the background, related research, P2P network technology, JXTA technology and SIP. Second, feasibility of the P2PSIP system is analysised, which includes the combination of P2P and SIP, the structure of the system network and the structure of the frame. Then, JXTA routing mechanism is researched, which includes shared resource distributed index, limited-range walk, rendezvous PeerView and loosely consistent DHT (Distributed Hash Table). Cosidering the disadvantages of limited-range walk and loosely consistent DHT, improvement strategy is put forward that Chord ring of consistent hashing algorithm is used in rendezvous network. P2PSIP system is designed and implemented, including Peer to join and to leave, user agent logon and location, and establishment of a session. Implementation of user agent location that is the collaborative process of discovery service, reslover service, rendezvous service and endpoint service, is described in detail. Finally, the function of the system is verified by testing.