Client-based Internet Protocol version 4-Internet Protocol version 6 translation mechanism for Session Initiation Protocol multimedia services in next generation networks

In the `Next Generation Networks´, `Session Initiation Protocol´ (SIP) is widely used to control multimedia (e.g. voice and video) sessions and `Internet Protocol version 6´ (IPv6) is adopted to provide enough addressing space. However, in the current stage of IPv6 deployment, the newly IPv6-enabled device [i.e. typically internet protocol version 4 (IPv4)/IPv6 dual-stack device] may connect to an existing IPv4 device. In the traditional `server-based solutions´, the SIP server is modified to perform the IPv4-IPv6 translations to the SIP messages and the real-time transport protocol (RTP) packets. However, the IPv4-IPv6 translations increase the call setup latency, the RTP transmission delay and the packet loss possibility. To reduce the drawbacks, this study proposes a `client-based solution´, where the client (i.e. the end device) instead of the SIP server performs the IPv4-IPv6 translation. The authors utilise the message flows to elaborate three server based and the proposed client-based solutions. In addition, the authors implement all solutions and deploy them in an IPv4-IPv6 interworking testbed. By using the testbed, the authors analyse these solutions in terms of the `UA modification, the SIP Server modification, the call setup complexity and the RTP translation´.