Blocking and unblocking circuits

This topic describes the following processes for blocking and unblocking circuits:

Application blocking a circuit

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:

 

Far exchange blocking a circuit

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:

 

Application unblocking a circuit

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:

 

Far exchange unblocking a circuit

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: