Overload Control with Hybrid SIP Signaling - Using Smart Reliability and Priority Queuing Strategies

Abstract

Session Initiation Protocol is an IP based application level signaling protocol. SIP employs request retransmission for enabling reliability over UDP transport. This research work proposes a Hybrid SIP System that integrates the congestion control techniques from the proposed Smart Reliable SIP and Overload control using Advanced Smart Priority (ASP) Queuing Strategy. The proposed system reduces retransmissions and queuing delays in SIP servers. Smart Reliable SIP (SRSIP) implements the modified Selective Repeat ARQ protocol for enabling reliability of SIP requests without violating the SIP core functionality. SRSIP reduces the number of retransmissions. ASP Queuing Strategy prioritizes the SIP requests based on the retransmissions. The proposed system reduces the queuing delays for request processing at the downstream server and the retransmissions over the network. The Hybrid models integrates the features of both Smart Reliable SIP and ASP queuing strategy resulting in a system with almost zero retransmissions and reduced queuing delay for request processing.