ISUP, short for ISDN User Part, is a signaling protocol used in telecommunications networks to set up, control, and terminate telephone calls over the Integrated Services Digital Network (ISDN). It is a critical component of the ISDN architecture and is responsible for managing call signaling and related information exchange between network elements, ensuring efficient and reliable communication.
ISUP operates at the network layer level and is primarily used in Public Switched Telephone Networks (PSTNs) or private telephone networks that make use of ISDN technology. This protocol allows for the establishment and release of voice and data circuits, as well as the exchange of call-related parameters between telephone exchanges or switches.
ISUP messages contain information about the caller and called parties, call state information, call progress, call transfer, and other necessary details for call control and management. The protocol defines different message types and procedures for call setup, call routing, call teardown, and network management.
By using ISUP, network operators can effectively control and manage voice and data connections, ensuring efficient utilization of network resources and providing reliable call setup and termination services. ISUP is an integral part of the global telecommunications infrastructure, enabling seamless communication between different networks, carriers, and devices in the ISDN ecosystem.
