The Secure Architecture Design Of SIP Over P2P System

SIP has already become one of the two main VoIP protocols because of its simplicity and flexibility. While with the rapid development, it also comes to some problems. The C/S model makes it difficult for SIP to solve the one-point failure and performance bottle-neck problem. While Skype sucessfully solves this problem through the P2P technology. According to the statistic analysis, the quality of communication is still well when there are more than 7 million Skype clients online at the same time. Because of Skype's success, IETF considers to reconstruct SIP through P2P technology.This thesis is concerned with the secure issues in the combination of P2P and SIP. According to the common secure threats in the current P2P network and SIP, this thesis proposes a secure architecture.Secure access control, setting access control at the network interface, preventing malious nodes' access and guaranteeing the normal nodes' login.Redundance mechanism, storing network resources on multi-nodes.Secure communications, indentifying the other side of the communication in the session setting up process, and encrypting communication content in the data trasportation process to prevent malious nodes' tampering;The reputation mechanism of multi-cast, discriminating and discarding malious nodes through voting mechanism. This thesis proposed the secure mechanisms above, and analyzed their application and performance in the system. At the end of the thesis, matlab is used to simulate the reputation mechanism.