Signalling System No. 7 - ISDN User Part Functional Description - Series Q: Switching and Signalling - Specifications of Signalling System NO. 7 - ISDN User Part Study Group 11; 22 pp
The ISDN user part is the signalling system No. 7 protocol which provides the signalling functions required to support basic bearer services and supplementary services for voice and non-voice applications in an integrated services digital network.