Integrating Voice over IP Services in IPv4 and IPv6 Networks

The transition from the current IPv4 network protocol structure to the next generation IPv6 network has always been deemed as a lengthy process. As the deployment of IPv6 infrastructures evolves, interaction with the existing IPv4 networks is unavoidable. This interaction may occur at the network level (simple data pass-through) or at the application level (between IPv6 and IPv4 endpoints). In this paper we concentrate on application level interoperability and select an increasingly popular application: Voice Over IP (VoIP). The use of VoIP technologies is becoming more widespread as end-users and network providers recognise the potential benefits that the usage of the application provides. It is important to provide an environment where IPv4 and IPv6 networks and applications / devices can interoperate in the context of VoIP. This environment is based on an architecture that integrates all the components together (whether they support IPv4 or IPv6 or both) thereby providing ubiquitous access to IP telephony services based on the SIP signaling protocol. We present our experiences from realising the proposed architecture.