NETWORK-CONTROLLED SIP SERVER SWITCHING METHODS FOR ACTIVE SIP SESSIONS

摘要

Recently, SIP (Session Initiation Protocol) has been used primarily for call control of many services over IP networks. SIP messages are often routed through SIP proxy servers (SIP Server) for accounting and communication control. However, the route of SIP servers is fixed after establishing a session. Therefore, the SIP servers must continue to process the SIP messages of the session until the session ends. This raises the cost of SIP servers due to the need for redundancy mechanisms and high performance to deal with system failures and high-load processing. In addition, operators have to wait until all sessions are finished before the SIP server can be shut down for maintenance. In this paper, we focus on switching SIP servers and propose network-controlled SIP server switching methods for active sessions in order to solve the above-described problems. Further, we implement and evaluate our proposed methods and demonstrate their performance.