IPv4-IPv6 translator for VoIP and video conferencing

As migration to IPv6 occurs slowly, IPv4 and IPv6 hosts will coexist for many years. We consider a specific scenario where the legacy IPv4 systems can not be upgraded and also the new systems are IPv6. The mix of IPv4 and IPv6 machines exist in the same network and both need to interoperate. We propose a novel Translator called SBIIT (Socket identifier Based IPv4/IPv6 Translator), which is based on a modification of NAT-PT. SBIIT provides support for SIP, SAP and multicast translation. To do this, translation has to be performed in packet headers as well as in payloads, because these protocols embed IP addresses in payloads. Moreover, this is achieved without any modifications to v4/v6 end hosts. We design and implement SBIIT in hardware using the network processor IXP 435 from Intel. Extensive tests demonstrate that the Translator is able to provide seamless interoperability between v4 and v6 hosts running applications based on SIP, Multicast, TCP, UDP as well as ICMP.