A Home Gateway (HGW) interconnects a Home Network (HN) and an External Network (EN), and is adapted to communicate with the HN and EN at a Network layer. HGW is provided with a Service Application Programming Interface Layer (SAPI Layer) capable of performing, at an Application layer, mediator functions for supporting communication and services between the HN and EN. Devices of the HN are able to communicate with devices of EN via the HGW, and to actualize services via the HGW.