Improving Query for P2P SIP VoIP

P2PSIP (Peer-to-Peer SIP) is proposed to provide fully distributed multimedia communication systems. However, as the two sides of a coin, P2PSIP has improved the reliability and scalability of the traditional SIP (Session Initiation Protocol) networks, but also reduced the query performance of P2PSIP networks. In P2PSIP networks, the address resolving mechanism of the DHT (Distributed Hash Table) overlay is used to discover the IP address of the corresponding target user. Since there might be multiple overlay hops in resolving procedure, each of which is doing potentially time-intensive operations, it is high likely that the distributed characteristics of DHT overlay might result in an excessive CSD (Call Setup Delay), which is one of important indicators of the query performance of P2PSIP networks. In this paper, to improve the query performance of P2PSIP networks, we propose three approaches, including Bidirectional Chord, Asynchronous processing and Load balancing. By comparing experimental results in terms of RPS (Registrations-Per-Second), CPS (Calls-Per-Second) and CSD under traditional and improved P2PSIP networks, we conclude that the combination of these three approaches can effectively improve the query performance of P2PSIP networks.