Performance Characterization of Signaling Traffic in IMS Virtualized Network

Virtualization gives different types of Mobile Virtual Network Operators (MVNO) the possibility to deploy their components more rapidly and at a lower cost. In this paper, we propose five scenarios for the virtualization of the IP Multimedia Subsystem (IMS) components and compare them to the non virtualized one. To assess the service quality of the signaling system in our proposed virtualized scenarios, we consider three signaling procedures, namely registration, voice session, and data session. This study investigates the delay for each signaling procedure as a performance metric. By applying a Markovian generic model to our scenarios, we calculate the pre-established performance metrics. Based on the comparison of the delays of each virtualized scenario with those of the non-virtualized one, we then evaluate the utility function, by which we mean the improvement or degradation of virtualized delays. Finally, we deduce the best scenario that ensures a good service quality for each MVNO type. The main results show that the virtualized Proxy Call Session Control Function (P-CSCF) represents the most efficient scenario for the MVNO voice type, while the scenario in which all CSCF components are virtualized provides the best results for the data type.