GetFarEndDtmfInfo

The GetFarEndDtmfInfo API procedure is used to determine the type of DTMF supported by the far end of a call.

For outgoing calls:
This API procedure can be called anytime after the media engine sends the SipOutgoingCallConnected event to the application.

For incoming calls:
This API procedure can be called anytime after the media engine sends the SipIncomingCallStart event to the application.

For most applications, this API procedure can simply be called when the call enters the SipInCall state. The application can then save the returned API data to a temporary location and refer to it as required for the duration of the call.

TELEPHONY_RETURN_VALUE GetFarEndDtmfInfo(

SIPHANDLE hStateMachine,

int PhoneLine,

DTMF_FAR_END_INFO *pFarEndDtmfInfo

);

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.

pFarEndDtmfInfo

[out] Specifies the location of an application supplied DTMF_FAR_END_INFO structure that will contain the return values.

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.
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.
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.