The Design And Realization Of SuperNode Server In SIPGrid System

Presently as the key protocol used in NGN, SIP is becoming the focus of thetelecom service providers. P2P is a new growing technology which is the focus of IP, and brings lots of applications. SIPP2P combine the advantage of SIP protocol and P2P technic to provide more stable foundation for IP multimedia communication system.Against problems of systems based on SIP or P2P, the paper advances a new IP multimedia communication system by research of SIPP2P. SIPGrid is a multimedia communication system in mode of signaling centralized and media flow transmitted by P2P. The mode not only avails to monitoring, controlling of charging, management of calling, but also makes transmission of media flow more fluently.The goal of this paper is to design and realize important function entity SuperNode server in SIPGrid. SuperNode server forms a overlay network by existent structural P2P network OpenDHT and accomplish application layer and P2P network layer to relay, IPType and STUN service for other nodes. Main content contains:(1)Introduce multimedia communication system of NGN brought by combined SIP with P2P based on the standard of SIP protocol and distribution of P2P network. Summarize SIP element, realization mechanism, topology of P2P network and so on.(2)Introduce SIPGrid consisting layer framework, foundation, maintenance and resource orientation of P2P network, relay server and action of SuperNode server.(3)Against function and status of SuperNode server in SIPGrid, address design mechanism, function, message and application service applied by SuperNode.(4)Detailedly introduce function of SuperNode, such as event mechanism, timer mechanism, relay service, IPType service, multilevel NAT transfer and so on, and realization of message. At the same time illustrate some detailed realization.(5)Against compatibility of traditional SIP terminal, relay service, IPType service and NAT/Firewall transfer, constitute a test platform of SIPGrid to test function of SuperNode and analyze result of test to improve communication quality.