Improving The Query Performance Of P2PSIP Networks

There are so many problems in the VoIP (Voice on Internet Protocol) systems basedon SIP (Session Initiation Protocol), such as performance bottlenecks, single point of fail-ure, poor extensions and so on. The P2PSIP (Peer-to-Peer SIP) is proposed to optimize thecentralized SIP architecture using P2P distributed technology. Bringing the benefits suchas reliability and scalability into the VoIP system, the P2PSIP also introduce a new prob-lem of query efficiency.We take into consideration the querying effiency of Chord algorithm, the processingperformance of P2PSIP servers and the load balancing of P2PSIP networks. From threeaspects we improve the query performance of P2PSIP networks, including the efficiencyimprovement of P2P query, the performance enhancement of parallel query and the loadbalancing of P2PSIP networks.The efficiency improvement of P2P query includes optimizing basic Chord algorithmso as to support bidirectional query, semi-recursive routing and cache record. Compared tothe traditional Chord algorithm, the improved Chord algorithm greately improves the effi-ciency of P2P query in the P2PSIP network. The performance enhancement of parallelquery includes using the asynchronous processing instead of asynchronous processing oftraditional SIP servers, which can improve the processing performace of a single P2PSIPserver. The load balancing of P2PSIP networks includes using the appropriate load bal-ancing algorithm to distribute workloads among P2PSIP servers in the P2PSIP network soas to achieve efficient resources utilization.From the two aspects of system simulations and actual deployments of the improvedP2PSIP network, as well as the original one, we make comparison tests between them. Thetest results show that:1) the average query hops of improved Chord reduce by25%thantraditiaonal Chord;2) the SIP server using asynchronous processing mechanism can han-dle more than40%of the number of calls per second than traditional SIP server;3) theaverage call setup delay of improved P2PSIP networks remain within the1200ms range,which is in line with the recommended standards ofthe International TelecommunicationUnion on Internet telephony.