This topic describes the following processes for blocking and unblocking circuits:
The application requests blocking of a circuit by invoking TUPStatusReq with the event type of TUPCIRBLKREQ. The application can consider the circuit blocked or unblocked when issuing this request. The following illustration shows how the application initiates a blocking request:
If the far exchange initiates the blocking of the circuit, the application receives a status indication (EVTTUPSTAIND) with the event type of TUPCIRBLKREQ from the TUP layer. The TUP task acknowledges the block for the application. The following illustration shows how a far exchange-initiated blocking request is conducted:
The application requests unblocking of a circuit by invoking TUPStatusReq with the event type of TUPCIRUNBLKREQ. The following illustration shows how the application initiates an unblocking request:
If the far exchange initiates the unblocking of the circuit, the application receives a status indication (EVTTUPSTAIND) with the event type of TUPCIRUNBLKREQ from the TUP layer. The TUP task then acknowledges the circuit unblocking. The following illustration shows how a far exchange-initiated unblocking request is conducted: