Performance Modelling and Optimization of IP Multimedia Subsystem

This paper proposes a Session Initiation Protocol (SIP) message classification and prioritization scheme. This three-priority classification of SIP messages is implemented in Internet protocol Multimedia Subsystem (IMS). Its effectiveness is verified through the analytical and simulation modelling of IMS using a queuing theory. The proposed IMS model is analysed in the normal load and overload conditions. The analytical and simulation results are compared in terms of utilization, mean waiting time, and mean queue length. The agreement between them verifies the applicability of the proposed model for IMS performance prediction and optimization. Moreover, the simulation results show better performance of IMS in the overload situation when SIP message classification and prioritization scheme is used. Being linked to various research areas, this scheme is going to become a starting point for our future research activities.