General The Integrated Services Digital Network (ISDN) User Part (UP) defines the protocol which supports the signaling functions required to provide voice and non-voice services in an Integrated Services Digital Network. The ISDN User Part (ISUP) is also suited for application in dedicated telephone and circuit switched data networks and in analogue and mixed analogue/ digital networks. The ISDN User Part is based on@ and uses wherever applicable the same signaling procedures@ information elements and message types as the internationally specified ISDN User Part of ITU-T Signaling System No.7 (SS7)@ as described in: Q.730 (2000)@ ISDN supplementary services.1 Q.761 (2000)@ Functional description of the ISDN user part.1 Q.762 (2000)@ General function of messages.1 Q.763 (2000)@ Formats and codes.1 Q.764 (2000)@ Signaling procedures.1 Q.766 (1992)@ Performance objectives in the ISDN applications.1 The ISDN User Part is also based on and aligned with: Q.850 (1996)@ Usage of Cause and Location in the Digital Subscriber Signaling System No. 1 and the Signaling System No. 7 ISDN User Part.1 ATIS-1000607.2014@ American National Standard for Telecommunications - Digital Subscriber Signaling System No. 1 (DSS1) - Layer 3 Signaling Specification for Circuit Switched Bearer Service.2 In addition@ the ISDN User Part is aligned with: Q.724 (1988)@ Telephone user part signaling procedures.1 1 This document is available from the International Telecommunications Union. < http://www.itu.int/ITU-T/ >. 2 This document is available from the Alliance for Telecommunications Industry Solutions (ATIS)@ 1200 G Street N.W.@ Suite 500@ Washington@ DC 20005 < https://www.atis.org/docstore/product.aspx?id=24729 >.