Method to reduce SIP signaling messages during Glare conditions

Session Initiation Protocol is an IP based signaling protocol used for establishing, modifying and terminating sessions. During the signaling process, both the peers may initiate similar or controversial signaling messages resulting in Race / Glare conditions. SIP protocol handles glare conditions by transmitting the signaling messages after a random interval of time, within a specified time range. This process reduces the chances for occurring of glare conditions, but results in increased signaling messages.

This paper proposes a method for avoiding / reducing glare conditions for SIP BYE requests by enabling state-full SIP Proxy servers with extra intelligence to identify and reduce signaling messages transmitted end to end during Glare conditions. This work analyzes the amount of bandwidth reduced and number of signaling messages reduced with proposed method in scenarios where the glare condition is identified between two proxy servers and between a proxy server and a UserAgent and the glare condition that occurs at a proxy server.