General Aspects and Principles Relating to Recommendations on ISDN User-Network Interfaces - Integrated Services Digital Network (ISDN) - Overall Network Aspects and Functions, ISDN User -Network Interfaces (Study Group XVIII) 3 pp
Recommendation 1.120 gives the conceptual principles on which an ISDN should be based. The main
feature of an ISDN is the support of a wide range of service capabilities, including voice and nonvoice
applications, in the same network by offering end-to-