...

session.createStream({
    name: streamName,
    display: remoteVideolocalVideo,
    constraints: {
        audio: {
            stereo: true
        },
        ...
    }
    ...
}).publish();

...

If echo cancellation is enabled, Chrome will publish mono audio even if stereo is set in Opus codec options.

How to bypass an encrypted UDP traffic blocking

Sometimes an encrypted UDP mediatraffic may be blocked by ISP. In this case, WebRTC stream publishing over UDP will fail with Failed by RTP activity error. To bypass this, it is recommended to use TCP transport at client side

session.createStream({
    name: streamName,
    display: localVideo,
    transport: "TCP"
    ...
}).publish();

Another option is to use external or internal TURN server or publish a stream via RTMP or RTSP.

Known issues

1. If the web app is inside an iframe element, publishing of the video stream may fail.

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