close search

Add Messaging, Voice, and Authentication to your apps with Vonage Communications APIs

Visit the Vonage API Developer Portal

Moderation — Windows

When you connect to a session with a token that includes moderator privileges, you can force other clients to mute their audio:

Checking for moderation privileges

The ability to force mute streams is reserved for clients that are connected with a token that has been assigned the moderator role. Once you have connected to a session, you can check if the client can moderate by checking the value of the CanForceMute property of the Session.Capabilities object.

if (session.Capabilities.CanForceMute) {
    // The client can forceMute. See the next section.
} else {
    // The client cannot moderate.

Muting the audio of streams in a session

Moderators can force all clients or a publisher of a specific stream to mute their published audio.

To force a publisher of a specific stream to mute its audio, call the forceMuteStream() method of the Session object, passing in the Stream object corresponding to the stream to be muted:


When the call to the Session.ForceMuteStream() method fails, the Session object sends the Error event. For example, if the client does not have moderation privileges, the ErrorCode parameter passed in with the ErrorEventArgs object is set to SessionUnableToForceMute. In this context, success indicates that the options passed into the method are valid and the request to mute the stream was sent. It does not guarantee that the request was successfully acted upon.

Moderators can also force all streams (except for an optional array of streams) in a session to mute published audio. Call the ForceMuteAll() method of the Session object, passing in an enumeration of excluded streams that you want to exclude from muting:


A stream published by the moderator calling the ForceMuteAll() method is muted along with other streams in the session, unless you add the moderator's stream (or streams) to the excluded streams array.

If you leave out the excludedStreams parameter, all streams in the session (including those of the moderator) will stop publishing audio:


Also, any streams that are published after the call to the Session.ForceMuteAll() method are published with audio muted. You can remove the mute state of a session by calling the Session.DisableForceMute():


After you call the Session.DisableForceMute() method, new streams published to the session will no longer have audio muted.

You can get references to Stream objects when Session object sends the StreamReceived event, which includes a Stream arguement. See Detecting streams in a session. You can also get a Stream object from the Stream property of a Publisher or Subscriber object.

When the stream is muted as a result of one of these methods (or from a force mute stream call in another client SDK), in each client publishing a muted stream, Publisher objects send MuteForced events.

Similarly, in response to a call to the Session.ForceMuteAll() method (or to a force mute all call in another client SDK), the Session object sends a MuteForced event in each client connected to the session, and the IsActive property of the MuteForcedEventArgs object is set to true.