This Recommendation describes an application for authentication, authorization and accounting (AAA) for next generation networks (NGNs) based on [b-ITU-T Y.2201]: NGN release 1requirements, [b-ITU-T Y.2012]: Functional requirements and architecture of the NGN release 1(FRA), [b-ITU-T Y.2701]: Security requirements for NGN release 1, and [b-ITU-T Y.2702]: NGN authentication. This Recommendation applies to the authentication, authorization and accounting process in accessing an NGN using the AAA client and AAA server. In particular, this Recommendation addresses the accounting function only from the standpoint of its contribution to security accounting.