Evaluating Performance Characteristics of SIP over IPv6

Due to the ongoing massive growth of the global Internet, the rising integration of Voice over IP (VoIP) services and the Fixed Mobile Convergence (FMC), the IPv6 protocol and the Session Initiation Protocol (SIP) are key technologies for the realization of next generation communications. For both topics, IPv6 and SIP, a lot of self-contained research has been done. However, the challenge of SIP over IPv6 as well as related issues and performance impacts were not considered so far. In this article, we close this gap and draw attention to theoretical and practical aspects of the integration of SIP and IPv6, referred to as SIPv6. In this context our special interest concerns the interworking of heterogeneous IP networks during the transition from IPv4 to IPv6 and their ramifications on the VoIP service. Inevitably, during this period of co-existence the available transition techniques have an impact on the network and application performance. To quantify this impact, we set up a SIPv6 VoIP testbed and measured the performance penalties introduced by four selected transition techniques. We characterize the performance of transition scenarios compared to native scenarios by presenting measurement results and gained insights. Our study reveals individual pros and cons of transition technologies and their available implementations.