Signaling Packet Aggregation and Compression in SIP Network: Modeling and Performance Evaluation

Abstract

Recent development in communications have increased the demand of internet protocol (IP)-based multimedia conferencing services. Session initiation protocol (SIP) is a signaling protocol used for providing group communication in IP-based next generation network. The conferencing frameworks proposed by Internet Engineering Task Force working groups has limited scalability due to the centralized management of conference control by a single server. In order to overcome this limitation, we propose multiple SIP packet aggregation and compression of common header part of each aggregated packet process. This mechanism increases the bandwidth utilization and processing capability of conference server. A queueing model is developed to describe the process of packet aggregation (PA) and compression at the edge proxy. Using the proposed queueing model, the steady-state probability distribution of the queue length is derived and the average packet transmission delay is obtained. We show the trade-off between the overhead gain and delay. Based on the analytical results, the maximum frame size is optimized for which the average delay of a packet transmission is minimum. A discrete event simulation is performed using network simulator 2 to implement PA and compression mechanism in a SIP network. Further, performance measures are numerically obtained from the simulation results. The simulation results discussed upon the key performance metrics for signaling protocols defined by the International Telecommunication Union (ITU) Telecommunication Standardization Sector (ITU-T E.721).