This Recommendation focuses on the aspects of functional architecture of Next Generation Network(NGN) evolution by adoption of Intent-Based Network. The topic of Intent Based Network is standardized in ITU-T by a series of Recommendations including ITU-T Y.2344 which provides the scenarios, framework and general requirements of Intent-Based Network in Next generation network evolution. This Recommendation specifies the background, general functional architecture and functionalities of the functional entities in NGN evolution by adoption of Intent-Based Network.