Circuit unblock request

A circuit unblock request (CIRUNBLKREQ) indication is delivered to the application when the ISUP layer receives an unblocking message (UBL) from the far exchange. The application must consider the referenced circuit to be remotely unblocked. The application must then acknowledge the unblocking message by sending an unblocking acknowledgment message using ISUPStatusReq.

Note: Circuit unblock request status indications are not supported in BICC.