Recommendation ITU-T Y.2059 provides the impact study, scenario analysis and functional requirements for the networks which are connected to the IPv6-based NGN. It involves both the access network side and the core network side of NGN.
All the analysis is basically divided into two aspects, which are IPv6 connectivity and IPv4‑compatible connectivity. IPv6 connectivity focuses on IPv6-only network provision which contains prefix and address allocation, configuration, etc. IPv4-compatible connectivity focuses on IPv4-to-IPv6 transition technologies that continue to provide IPv4 services to users.