A peer-to-peer solution for SIP servers cooperation in wireless mesh networks

Deploying SIP services in wireless mesh networks is valuable for communication scenarios without infrastructure. In traditional method of SIP service provision, severs work individually without cooperation, and there exist such problems as low availability of resources and high cost of information update. In our multi-servers cooperation scheme for providing SIP services in wireless mesh networks, all servers are placed in an overlay. The overlay is built on Chord algorithm with 2 modifications; one is recording the information of all nodes in route table, the other is replicas-distribution by equal-distance hashing method. Theoretical analysis and comparison on performance were made among the scheme without cooperation, Chord-based cooperation scheme, and our scheme. And our scheme is proved to be superior in such metrics as query-delay and maintenance cost, and is especially applicable for networks with fixed number of servers and a lot of dynamic SIP users. Simulation results verified that our scheme can guarantee higher query-hit-ratio and forwarding speed, and decrease the overhead of network traffic.