A SAN-Based Modeling Approach to Performance Evaluation of an IMS-Compliant Conferencing Framework

This paper proposes a Stochastic Activity Networks (SANs) based approach to performance analysis of a conferencing framework compliant with the IP multimedia core network subsystem specification. The proposed approach relies on the OsMoSys modeling methodology and applies some concepts of component software engineering to the development of formal models. The paper introduces the possibility of building template models in order to enable the definition of families of models and describes the implementation of a library of reusable SANs modeling the components of the conferencing framework. Starting from the model library, we analyze the performance of a current implementation of the conferencing framework by instantiating and composing SAN models. Scalability and computational complexity are also addressed. We validate the resulting model of the conferencing system and discuss the advantages of the proposed approach through a comparative analysis with the results of an experimental campaign conducted over a real-world testbed implementation.