Another type of APPC error occurs when the MVS™ callable system service that attempts to perform an APPC function never completes. One way this can occur is if the partner remote RACF® subsystem address space starts the TP program, but does not complete the request. A missing interrupt handler (MIH) uses a timer to wait for the transaction to complete. When the timer expires, the MIH breaks the connection and declares an error. The connection between the two nodes is marked as operative in error and message IRRC022I is issued.