signalling connection control part (SS7) (SCCP)

The Signaling Connection Control Part (SCCP) is a signaling control part with additional functions for the Message Transfer Part( MTP) in SS7 signaling.

The SCCP part provides the ability to transfer messages connection-oriented or connectionless between any nodes in the signaling network. Typically, it supports the Transaction Capabilities Application Part ( TCAP).

SCCP defines routing functions derived from call numbers and also has management functions for subsystem usage. For the connection type, SSCP defines four service classes, identified by the digits 0 to 3. Service class 0 operates connectionless, sending data to the destination without a session being established. Service class 1 is also connectionless and without sequence control. Messages are guaranteed to reach the destination within the sequence. Service class 2 is connection oriented and the session of the SCCP connection is negotiated beforehand, and service class 3 is also connection oriented and has flow control.