Summary

Recommendation ITU-T Y.2058 specifies multiple phases for next generation network (NGN) operators to migrate from an Internet protocol version 4 (IPv4)-based NGN to an Internet protocol version 6 (IPv6)-based NGN. The migration includes five phases from a pure IPv4-based NGN to a pure IPv6‑based NGN. General functional requirements of migration are given as are specific functional requirements for each phase.