This Recommendation identifies service requirements and functional framework for the support of VPN services in NGN@ including the mobile environment. The provision of VPN services in NGN@ including the mobile environment@ covers the support of mobility management functions across different fixed and wireless network domains as well as at different network levels including intra-access network@ inter-access network@ and inter-network levels [ITU-T Q.1706]. This includes mobility support at the NGN service stratum and the NGN transport stratum [b-ITU-T Y.2011]. The detailed definition of mobility management-related functions and architecture is outside the scope of this Recommendation.