Date Added: Jul 2011
The growing number of applications that use the Session Initiation Protocol (SIP) to manage media sessions over IP is placing increasing demands on the SIP Proxy Servers (SPS) that make up the core of the SIP network. In this paper, the authors investigate the performance of OpenSIPS, an open source SIP proxy server. They have collected a large set of experimental data to characterize the performance of the SPS under various call arrival rates and inter-arrival time distributions. Based on this measurements, they model the SIP proxy server as an M/G/1 queue. A key component of the model is a parameter that captures the interrupt overhead, i.e., the impact of interrupts on kernel service times.