Improving Performance and Reliability of IMS by Co-location DHT

IP Multimedia Subsystem is deemed to be the core of NGN (Next Generation Network) technology. IMS is considered as the important way to solve the fixed-mobile convergence and the combination of multimedia services. P2P technology is introduced to solve the complicated structure and high OPEX of IMS, so as to promote the reliability and extensibility. However the introduction of P2P technology brings extra DHT messages and query delay that might exacerbate the performance of IMS applications. This paper proposes a new strategy called co-located DHT IMS where the IMS servers are as co-located as possible on the same DHT node host to reduce the messages necessary to exchange among IMS servers, as well as the number of physical servers involved on the process of registration and session establishment. Performance evaluation shows that the messages are reduced to and the reliability of system is improved when compared to traditional IMS. Thus the co-location DHT IMS is a feasible alternative for implementation in real system.