Improving Performance of IMS Networks with Intelligent Message Processing

The 3GPP IP Multimedia Subsystem (IMS) is a standard [1] for real-time multimedia commu-nications services. IMS standards define open interfaces for session management among other areas. This allows the network provider to manage IP network, with all the carrier-grade attributes of switched circuit networks. The performance of IMS signaling impacts the session-carrying capacity of the network. In addition to the challenges posed by SIP[4] message processing, the number of the IMS elements in the signaling path and the SIP extensions add complexity and delay to establish sessions. Further, soft real-time applications such as voice calls and Push-to-talk pose stringent delay requirements to establish new sessions.. The performance of IMS signaling network will benefit from optimizations at different levels, ranging from message processing and scheduling to traffic routing and network design. In this work we focus on message processing and introduce different message prioritization polices beyond FIFO. Using simulation, we investigate different scheduling schemes at the IMS servers to support applications with varying latency requirements.