ToneController.IncomingFaxDetected Event
Definition
Important
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Raised when a fax tone is detected.
public:
event EventHandler<Microsoft::Rtc::Collaboration::AudioVideo::IncomingFaxDetectedEventArgs ^> ^ IncomingFaxDetected;public event EventHandler<Microsoft.Rtc.Collaboration.AudioVideo.IncomingFaxDetectedEventArgs> IncomingFaxDetected;member this.IncomingFaxDetected : EventHandler<Microsoft.Rtc.Collaboration.AudioVideo.IncomingFaxDetectedEventArgs> Public Custom Event IncomingFaxDetected As EventHandler(Of IncomingFaxDetectedEventArgs) Event Type
Examples
The following example shows how to subscribe to IncomingFaxDetected event.
C# Subscribing to IncomingFaxDetected event.
toneController.IncomingFaxDetected += delegate(object sender, IncomingFaxDetectedEventArgs args)
{
// fax is detected, if app knows how to handle it's time to transfer the call to a fax provider.
};
Remarks
A fax tone can be received in three different ways:
- A SIP re-INVITE has an a=image channel. The event is raised when AudioVideoFlow.State is Active.
- An out-of-band fax tone (CNG tone) is received. The event is raised when AudioVideoFlow.State is Active, AudioVideoFlow.ToneEnabled is true, and AudioVideoFlow.HoldType is None.
- An inband audio fax tone is received. The event is raised when AudioVideoFlow.State is Active, AudioVideoFlow.ToneEnabled is true, AudioVideoFlow.HoldType is None, AudioChannel.Direction is ReceiveOnly or SendReceive, and Audio is not muted.