ITU-T Y.2012 PDF

The objective of this Recommendation is to describe the functional requirements and architecture of the next generation network (NGN) [ITU-T Y.2001] taking into account the requirements and capabilities for ITU-T NGN as described in [ITU-T Y.2201]. This Recommendation defines functional entities (FEs) of the NGN and is a precursor to further identifying and designating reference points, and defining information flows across such reference points.

The functional architecture provided in this Recommendation allows a clear distinction between the definition/specification aspects of services provided by the NGN and the actual specification of the network technologies used to support those services. In line with [ITU-T Y.2011] principles, an implementation-independent approach is adopted. This Recommendation describes the functional architecture of the NGN by using the generic definitions, symbols, and abbreviations that are defined in related ITU-T Recommendations.

Although the scope of this Recommendation is targeted primarily at an NGN architecture, it is clear that the accommodation of legacy PSTN/ISDN terminals and/or interworking with the PSTN/ISDN is an important consideration with respect to NGN deployment. Thus, to provide a more comprehensive view, certain functional elements required to accommodate PSTN/ISDN terminals and interworking with the PSTN/ISDN are shown/described even though they are not strictly part of the NGN architecture itself.

This Recommendation provides support for nomadism between different network termination points as well as transport level mobility.

Administrations may require network operators and service providers to take into account national regulatory and national policy requirements in implementing this Recommendation.

Note that Annex A provides a high-level description of the main additional features provided in this Recommendation as compared to the 2006 edition of this Recommendation.