# nccUnblockCalls

Releases the block on incoming calls.

#### Prototype

DWORD nccUnblockCalls ( CTAHD linehd, void *unblockparms )

Argument | Description
linehd | Line handle used to open the NCC service instance.
unblockparms | Pointer to a protocol-specific Natural Access call unblocking parameter structure. Protocol-independent applications can pass NULL for this argument to use the defaults. See the protocol-specific documentation for details.

#### Return values

Return value | Description
SUCCESS |
CTAERR_INVALID_HANDLE | The NCC service is not open on the specified handle.
CTAERR_INVALID_STATE | The specified line is not in the blocking state, and no previously invoked nccBlockCalls is pending.
CTAERR_SVR_COMM | A server communication error occurred.

#### Events

Event | Description
--- | ---
NCCEVN_CALLS_UNBLOCKED | The unblock calls request completed successfully. The line state changed to idle.
NCCEVN_UNBLOCK_FAILED | The request to unblock calls failed. The event value field contains the reason. For a list of reason codes, see NCCEVN_UNBLOCK_FAILED.

#### Details

nccUnblockCalls cancels call blocking on the specified line handle. When the line state changes to idle, NCCEVN_CALLS_UNBLOCKED is generated. The application can then receive or place new calls.

Use nccUnblockCalls to cancel a previous nccBlockCalls invocation before the protocol is able to start blocking calls on the specified line. In this case, the application receives no events.

If the request fails, the application receives NCCEVN_UNBLOCK_FAILED. The line remains in the current state.