An Optimized Algorithm for Overload Control of SIP Signaling Network

The session initiation protocol (SIP) is rapidly being adopted as the signaling protocol for establishing, modifying and terminating multimedia sessions. With the increasing use of SIP in large deployments, it is now becoming apparent that the SIP servers are not well equipped to handle overload conditions. When a SIP server is operating close to or above its capacity limit, message retransmissions can cause the network to be severely overloaded and result in an extremely low throughput. In this paper reasons that cause performance degradation are analyzed, and an optimized algorithm that randomly makes the decision of acceptance or rejection of every SIP message is proposed for overload control of SIP signaling network. The algorithm is verified and analyzed with simulation, and the result show that this solution can restrain throughput jitter and better meet the demand on SIP signaling network under heavy load.