Connecting IPv6 and IPv4 remains a challenge with the slow migration to IPv6 and support for legacy devices requiring IPv4. The three top options available to facilitate IPv4 and IPv6 communication are dual-stack networks, tunneling, and translation.
For Service Providers to deliver IPv6, they use translation technologies. The two major translation technologies are the Network Address Translation IPv6 to IPv4 (NAT64) and Stateless IP/ICMP Translation (SIIT). NAT64 is similar to the IPv4 Network Address Translation but is specific to IPv6. SIIT is capable of replacing IPv4 and IPv6 as part of the translation.