Transition to IPv6 with Realm Gateway 64

The IPv4 address space has been depleted and the usage of IPv6 is still very limited, however increasing. Smooth coexistence of IPv4 and IPv6 can support the development of the next generation Internet. During the transition there will be IPv4-only, IPv6-only and dual-stack hosts and network segments. This paper presents Realm Gateway 64 (RGW64) ? a solution for interconnecting heterogeneous network realms as defined by the IETF, which does not require changes in end-hosts. RGW64 relies on stateful DNS64/NAT64 translation and DNS resolution for establishing inbound connections. An analysis of the scalability and the security is also presented. The paper shows that RGW64 is suitable for operators who want to gradually migrate customer networks to IPv6 yet maintaining reachability with the IPv4 Internet.