This paper proposes that the end user\´s perception of an "ISDN service" should reflect\´three interrelated ISDN aspects, namely:

ISDN terminal capabilities,

ISDN access capabilities, and

ISDN network capabilities. Emphasis is placed on the ISDN terminal capabilities in supporting integrated services delivery of different levels to the end user (e.g., integrated bearer services and integrated teleservices delivery). Such a concept, integrated services delivery, is seen to suggest a useful framework for developing a wide range of possible ISDN commercial service/ product offerings. An ISDN service scenario is also described to illustrate some important communication capabilities made possible by an ISDN environment.