SipDialing

This event signals the start of DTMF tone generation by the telephony engine for an outgoing phone call. The application always receives this event notification regardless of the internal DTMF tone generation enable state.

The DTMF internal enable state is set by calling the EnableOutgoingDtmfDigits API procedure.

If an application disabled internal DTMF tone generation, the application software can process this event by playing whatever DTMF or other tones as required. If an application plays its own DTMF tones for the phone call, it should synchronously play all DTMF digits in the event handler before returning from the event handler.