To close the SSCP connection, an application sends a Close(SSCP) Request to the local node, which responds with a Close(SSCP) Response. The Close(SSCP) Request is unconditional; the Close(SSCP) Response always reports that the connection was successfully closed. The Close(SSCP) Response is provided so that applications can determine when outstanding data and status messages on the session have been delivered.
If the LU is bound, the local node sends a TERM-SELF message to the SSCP on behalf of the application to elicit an UNBIND. An application that merely wishes to be unbound need only issue Close(PLU) (see Closing the PLU Connection). Normally the SSCP connection can be maintained while the application task is active, even if it is idle.
Closing the connection invalidates the LPI pair for the connection but does not alter the state of the SSCP session. The message flow is shown in the following figure.