# NCC events and call states

The following table specifies standard NCC events that the application can expect to receive for a call when the call is in a particular call 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 indicated states if the NCC_CAP_HOLD_IN_ANY_STATE bit is set in the capabilitymask returned by nccQueryCapability.

NCC event | NCC call state
--- | ---
Accepting | Answering | Connected | Disconnected | Incoming | Outbound initiated | Placing | Proceeding | Receiving digits | Rejecting | Seizure
NCCEVN_ACCEPTING_CALL |  |  |  |  | X |  |  |  | X |  |
NCCEVN_ANSWERING_CALL | X |  |  |  | X |  |  |  | X |  |
NCCEVN_BILLING_INDICATION |  |  | X |  |  | X | X | X |  |  |
NCCEVN_BILLING_SET |  |  |  |  | X |  |  |  |  |  |
NCCEVN_CALL_CONNECTED |  | X |  |  |  |  | X | X |  |  |
NCCEVN_CALL_DISCONNECTED | X | X | X |  | X | X | X | X | X | X | X
NCCEVN_CALL_HELD (*) | X * | X * | X | X * | X * |  | X * | X * | X * | X * | X *
NCCEVN_CALL_PROCEEDING |  |  |  |  |  |  | X |  |  |  |
NCCEVN_CALL_RELEASED |  |  |  | X |  | X |  |  |  |  |
NCCEVN_CALL_RETRIEVED (*) | X * | X * | X | X * | X * |  | X * | X * | X * | X * | X *
NCCEVN_CALL_STATUS_UPDATE | X | X | X | X | X | X | X | X | X | X | X
NCCEVN_CALLID_AVAILABLE | X | X | X | X | X | X | X | X | X | X | X
NCCEVN_EXTENDED_CALL_ STATUS_UPDATE | X | X | X | X | X | X | X | X | X | X | X
NCCEVN_HOLD_REJECTED (*) | X * | X * | X | X * | X * |  | X * | X * | X * | X * | X *
NCCEVN_INCOMING_CALL |  |  |  |  |  |  |  |  | X |  | X
NCCEVN_PLACING_CALL |  |  |  |  |  | X |  |  |  |  |
NCCEVN_PROTOCOL_ERROR | X | X | X | X | X | X | X | X | X | X | X
NCCEVN_PROTOCOL_EVENT | X | X | X | X | X | X | X | X | X | X | X
NCCEVN_RECEIVED_DIGIT |  |  |  |  |  |  |  |  | X |  | X
NCCEVN_REJECTING_CALL | X |  |  |  | X |  |  |  | X |  |
NCCEVN_REMOTE_ALERTING |  |  | X |  |  |  |  | X |  |  |
NCCEVN_REMOTE_ANSWERED |  |  | X |  |  |  |  | X |  |  |
NCCEVN_RETRIEVE_REJECTED (*) | X * | X * | X | X * | X * |  | X * | X * | X * | X * | X *