ToneController.IncomingFaxDetected Event
Raised when a fax tone is detected.
Namespace: Microsoft.Rtc.Collaboration.AudioVideo
Assembly: Microsoft.Rtc.Collaboration (in Microsoft.Rtc.Collaboration.dll)
Syntax
'Declaration
Public Event IncomingFaxDetected As EventHandler(Of IncomingFaxDetectedEventArgs)
'Usage
Dim instance As ToneController
Dim handler As EventHandler(Of IncomingFaxDetectedEventArgs)
AddHandler instance.IncomingFaxDetected, handler
public event EventHandler<IncomingFaxDetectedEventArgs> IncomingFaxDetected
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.
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.
};