An optimal rejuvenation scheme for improving VoIP service reliability in the existence of resource exhaustion and security breaches

Abstract

The escalating number of end-users of VoIP and the challenges faced in furnishing first-class quality of service (QoS) are the major driving forces for research in the area of VoIP. When the resources allotted to every end-user get exhausted, it leads to a decline in the QoS. Further, as VoIP is an application operating on the internet, it is prone to security breaches. This paper addresses the issues of resource exhaustion and security breaches in a VoIP network. To help avert performance degradation in a VoIP system, software rejuvenation is also performed. The performance of a VoIP system in the existence of resource exhaustion and security breaches is modelled by means of a continuous time Markov chain (CTMC) to study the system reliability. From the CTMC the mean time to failure (MTTF) is obtained. Furthermore, an optimal rejuvenation scheme is proposed for achieving the best attainable value of MTTF.