Next/New Generation Networks Services and Management

New/Next Generation Networks aim to provide mutual trusted IP Based Networks for a multi access network and innovative services tailored to users needs. NGN architecture has been the purpose of several studies within organism of standardization like ITU-T and ETSI. We present here a literature about NGN architecture (NGN) and Next/New Generation service (NGS) requirements: details about functionalities of NGN layers and IMS (IP Multimedia Subsystem) Architecture are in the scope of the paper. We also describe the service management aspects and its challenges while evolution towards NGS.