Complete Protocol dictionary, glossary and reference

ISUP: ISDN User Part

The ISDN User Part (ISUP), a key protocol in the SS7/C7 signaling system, defines the protocol and procedures used to set-up, manage and release trunk circuits that carry voice and data calls over the public switched telephone network (PSTN) between different switches. ISUP is used for both ISDN and non-ISDN calls.

Standard Organization

ITU-T

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