Research on Improving Strategies of SIP Session Setup Delay in IMS

SIP (Session Initiation Protocol) is used in IMS (IP Multimedia Subsystems) to perform multimedia session setup and maintenance. However, SIP is text-based and has large messages with size frequently exceeding several hundred bytes during the setup session. It causes more setup session delay, especially for application in narrowband system. It is necessary to SIP signaling compression and optimization flow of session setup to reduce the session setup delay. In this paper, the relationship between SIP signaling compression and shortening of session setup delay is obtained. According to optimization flow of session setup for shorten the session setup delay, the test is achieved. The results of experiment show that this method can effectively shorten the session setup delay.