ISUP Overview

Description: OpenSS7 SS7 Stack Overview.

This is the Signalling System No. 7 (SS7) Integrated Services Digital Network (ISDN) User Part (ISUP) component of the OpenSS7 stack. This component implements ISUP functions in a STREAMS multiplexing driver.

Originally it was believed that the ISUP component would be more properly placed in user-space; however, the current implementation implements the entire ISUP call control and signalling functions in the kernel in a STREAMS multiplexing driver.

The ISUP STREAMS driver provides a Call Control Interface (CCI).

An additional ISUP management interface is provided to allow for Continuity Testing and Test Calls as well as circuit management (blocking, unblocking) capabilities.

The ISUP STREAMS driver supports I_LINK and I_PLINK of Message Transfer Part Interface (MTPI) streams providing SS7 MTP-SAPs under the multiplexing driver.