NCC functions and line states

The following table lists which NCC API calls can be made from each of the states of the line state machine.

Note: Functions marked by an asterisk can be performed in the idle line state on a call that is held, if supported by the service implementation and protocol. The NCC_CAP_HOLD_IN_ANY_STATE indicator in the capabilitymask returned by nccQueryCapability indicates if the protocol allows calls to be held or retrieved from any state.

NCC function	Line state
NCC function	Active	Blocking	Idle	Out of service	Uninitialized
nccAcceptCall (*)	X		X
nccAnswerCall (*)	X		X
nccAutomaticTransfer	X
nccBlockCalls	X		X	X
nccDisconnectCall (*)	X		X
nccGetCallStatus	X		X
nccGetExtendedCallStatus	X		X
nccGetLineStatus	X	X	X	X	X
nccHoldCall	X
nccPlaceCall	X		X
nccQueryCapability	X	X	X	X
nccRejectCall (*)	X		X
nccReleaseCall	X	X	X	X
nccRetrieveCall	X		X
nccSendCallMessage (*)	X		X
nccSendDigits (*)	X		X
nccSendLineMessage	X	X	X	X
nccSetBilling (*)	X		X
nccStartProtocol					X
nccStopProtocol	X	X	X	X
nccTransferCall	X
nccUnblockCalls	X	X	X	X

NCC functions and capability masks

The following table lists the functions that are not supported by some protocols and the name of the bit in the capabilitymask returned by nccQueryCapability that indicates if the function is supported.

NCC function	Capability mask
nccAcceptCall	NCC_CAP_ACCEPT_CALL
nccAutomaticTransfer	NCC_CAP_AUTOMATIC_TRANSFER
nccGetExtendedCallStatus	NCC_CAP_EXTENDED_CALL_STATUS
nccHoldCall	NCC_CAP_HOLD_CALL
nccRetrieveCall	NCC_CAP_HOLD_CALL
nccSendCallMessage	NCC_CAP_SEND_CALL_MESSAGE
nccSendDigits	NCC_CAP_OVERLAPPED_SENDING
nccSendLineMessage	NCC_CAP_SEND_LINE_MESSAGE
nccSetBilling	NCC_CAP_SET_BILLING
nccTransferCall	NCC_CAP_SUPERVISED_TRANSFER or NCC_CAP_TWOCHANNEL_TRANSFER

For more information, refer to Protocol capabilities.