Based On The P2p-sip Voip Voice Applications And Research

Voice communication technology has been widely used as the continuous development of the Internet, and transforms gradually from traditional PSTN network into IP network i.e. VOIP. As a result of this evolution, operators can introduce new business and integrate various multimedia services under the circumstance of lowering the cost. Therefore, the transformation of traditional phone network to IP telephony (VOIP) is the general trend.As in the existing VOIP system based on C/S Mode, users can communicate with others only when have been registered to the Centre Server, thus the server becomes the bottleneck of the system performance. P2P networks can make full use of customer node processing capabilities, and enhance the overall load capacity of the system while increasing the stability of the system. Thus, SIP, as the core protocol of VOIP technology, has been trying to transform from the C/S mode to P2P mode.This thesis first discusses the development of the VOIP from the subject background and needs; then analyses the key technologies of VOIP especially the SIP protocol and P2P technology and explores the application of P2P-SIP in VOIP voice system on this basis. As in P2P-SIP system nodes correspond to the UA in SIP system, this thesis highlights the joining, leaving and registering of the nodes, finding and locating resources by using Chord algorithm and the establishment of conversation. P2P-SIP system, solving the problems of single point failure and performance bottlenecks of SIP system, is not only reliable and scalable but also with good load balance and can exchange with the existing SIP system.