StopDtmfTone

The StopDtmfTone API procedure is used to terminate a currently playing DTMF tone. To start a DTMF tone, see the StartDtmfTone API procedure.

TELEPHONY_RETURN_VALUE StopDtmfTone(

SIPHANDLE hStateMachine,

int PhoneLine,

DTMF_TONE DtmfTone,

BOOL Synchronous

);

Parameters:

hStateMachine

[in] The handle to the telephony engine. This is the handle that was returned by a previous call to the StartSipTelephony procedure.

PhoneLine

[in] The zero based phone line to access. If you want to terminate DTMF on all phone lines, set this parameter to -1.

DtmfTone

[in] The DTMF tone to terminate.

Synchronous

[in] Specifies whether the tone will be terminated synchronously or asynchrounously. If the tone is terminated synchronously, the StopDtmfTone API procedure will not return until the DTMF tone is completely turned OFF.

Return Value:

If the function succeeds, the return value will be SipSuccess.

If the function fails, the return value will be one of the following values as specified by the TELEPHONY_RETURN_VALUE data type.

Value	Description
SipInvalidHandle	The hStateMachine parameter is invalid.
SipBadPhoneLine	The zero based phone line is invalid.
SipInvalidDtmfTone	The DTMF digit specified is invalid.
SipInternalDtmfSupportNotEnabled	Integrated DTMF has not been enabled in the media engine. For additional information, see the startup parameter DtmfEnabled of the START_SIP_TELEPHONY_PARAMS structure.
SipMemoryError	Indicates a low memory situation.
SipCallFailure	This is a generic "catch all" API error. If an error condition is not specified by any other API error value, this error will be returned.