The authors review the essential elements of the ATM (asynchronous transfer mode) technique and presents a framework for the definition of ATM, based on the ISDN (integrated-services digital network) protocol reference model. A layered functional model of an ATM open system is presented and the relation with existing packet techniques is studied. The use of ATM in the subscribers' premises network (SPN) is analyzed. A two-tier SPN architecture is proposed covering both residential and business environments, in line with the modeling principles outlined. The merits of this architecture in the field of standardization are emphasized. Some implementation issues and the relation with the reference configuration are discussed.>