NAT64 functionality is necessary for operators implementing IPv6 on their networks. This functionality enables carriers to transparently and manageably provide IPv6-based service users access to content and resources with IPv4 addresses by translating IPv6 addresses to public IPv4 addresses.
NAT64 is the NFWare vCGNAT
operational mode for mapping a customer IPv6 address to the public IPv4 address with one of its TCP or UDP ports. Because almost all services accessible on the public Internet are still IPv4 only, NAT64 is needed to allow customers who use IPv6-only devices to transparently access IPv4 services.