# NCC events and line states

The following table specifies standard NCC events that the application can expect to receive for a line when the line is in a particular line state. Other protocol-specific NCC events may be reported in most states. See the protocol-specific documentation for details.

Events marked with an asterisk (*) can occur in the idle state if the NCC_CAP_HOLD_IN_ANY_STATE bit is set in the capabilitymask returned by nccQueryCapability.

NCC event | Line state
--- | ---
Active | Blocking | Idle | Out of service | Initialized
NCCEVN_ACCEPTING_CALL (*) | X |  | X * |  |
NCCEVN_ANSWERING_CALL (*) | X |  | X * |  |
NCCEVN_BILLING_INDICATION (*) | X |  | X * |  |
NCCEVN_BILLING_SET (*) | X |  | X * |  |
NCCEVN_BLOCK_FAILED |  |  | X |  |
NCCEVN_CALL_CONNECTED (*) | X |  | X * |  |
NCCEVN_CALL_DISCONNECTED (*) | X |  | X * |  |
NCCEVN_CALL_HELD | X |  |  |  |
NCCEVN_CALL_PROCEEDING (*) | X |  | X * |  |
NCCEVN_CALL_RELEASED | X | X | X | X |
NCCEVN_CALL_RETRIEVED |  |  | X |  |
NCCEVN_CALL_STATUS_UPDATE | X |  | X |  |
NCCEVN_CALLID_AVAILABLE (*) | X |  | X * |  |
NCCEVN_CALLS_BLOCKED |  |  | X |  |
NCCEVN_CALLS_UNBLOCKED |  | X |  |  |
NCCEVN_CAPABILITY_UPDATE | X | X | X | X |
NCCEVN_EXTENDED_CALL_STATUS_UPDATE | X |  | X |  |
NCCEVN_HOLD_REJECTED | X |  |  |  |
NCCEVN_INCOMING_CALL (*) | X |  | X * |  |
NCCEVN_LINE_IN_SERVICE |  |  |  | X |
NCCEVN_LINE_OUT_OF_SERVICE |  |  | X |  |
NCCEVN_PLACING_CALL | X |  |  |  |
NCCEVN_PROTOCOL_ERROR | X | X | X | X |
NCCEVN_PROTOCOL_EVENT | X | X | X | X |
NCCEVN_RECEIVED_DIGIT (*) | X |  | X * |  |
NCCEVN_REJECTING_CALL (*) | X |  | X * |  |
NCCEVN_REMOTE_ALERTING (*) | X |  | X * |  |
NCCEVN_REMOTE_ANSWERED (*) | X |  | X * |  |
NCCEVN_RETRIEVE_REJECTED |  |  | X |  |
NCCEVN_SEIZURE_DETECTED | X |  | X |  |
NCCEVN_START_PROTOCOL_DONE |  |  |  |  | X
NCCEVN_STOP_PROTOCOL_DONE | X | X | X | X |
NCCEVN_UNBLOCK_FAILED |  | X |  |  |

## NCC events and parameter control

The following table lists NCC events that are controlled by parameters. For more information about parameters, see NCC API global parameters.

NCC event | Controlled by this parameter...
--- | ---
NCCEVN_BILLING_INDICATION | NCC_REPORT_BILLING bit in NCC.START.eventmask
NCCEVN_CALL_STATUS_UPDATE | NCC_REPORT_STATUSINFO bit in NCC.START.eventmask
NCCEVN_CALLID_AVAILABLE | NCC_REPORT_CALLID bit in NCC.START.eventmask
NCCEVN_EXTENDED_CALL_STATUS_UPDATE | NCC_REPORT_STATUSINFO bit in NCC.START.eventmask
NCCEVN_RECEIVED_DIGIT | NCC.START.overlapped receiving
NCCEVN_REMOTE_ALERTING | NCC_REPORT_ALERTING bit in NCC.START.eventmask
NCCEVN_REMOTE_ANSWERED | NCC_REPORT_ANSWERED bit in NCC.START.eventmask