Categories for Uncategorized

November 8, 2019

Removing Old Versions of DTLS

Contributed by Nils Ohlmeier, Hacking on real time communications since 2002

As you probably have read already old versions of TLS are going to be removed in March 2020. Obviously we don’t want to leave Firefox WebRTC users behind and vulnerable. Thus we are planing on disabling support for DTLS 1.0 also in March 2020.

According to our measurements the absolute majority (98.12%) of WebRTC services use DTLS 1.2 already today.

WebRTC DTLS usage numbers

The remaining 1.88% need to start upgrading to DTLS 1.2 today.

To help with the transition and testing we added new user preferences to Firefox 71 (currently available as Firefox Beta):

  • media.peerconnection.dtls.version.min = 770
  • media.peerconnection.dtls.version.max = 771

To test with DTLS 1.2 only simply open about:config and set media.peerconnection.dtls.version.min to 771. From now on your Firefox will no longer offer DTLS 1.0, as if it would be a release from March 2020.

July 1, 2019

Camera & microphone require https in Firefox 68.

Contributed by Jan-Ivar Bruaroey,

As of Firefox 68—releasing next week—camera and microphone will require an https connection to work. Access from insecure http will cease to work, matching how Chrome works. Camera and microhone are powerful features, and Firefox will now only expose them in secure contexts, a security and privacy improvement.

Largely an issue for developers to catch up on, this may nonetheless affect end users who follow old http links to servers that either still don’t redirect their users to https automatically, or don’t support it at all. If you’re experiencing this problem, click your URL bar, and if the URL starts with http, try changing it to https, and it should work again, provided the server supports https.

The rest of this blog post is for web developers, since there are some details that may be of interest to them. Firefox is deprecating camera and microphone access in insecure contexts in two steps: (more…)

April 7, 2019

Perfect negotiation in WebRTC

Contributed by Jan-Ivar Bruaroey,

New preface: What if you could add and remove media to and from a live WebRTC connection, without having to worry about state, glare (signaling collisions), role (what side you’re on), or what condition the connection is in? You’d simply call pc.addTrack(track, stream) regardless of time and place, and your track would just show up on the opposite side, without risk of terminal connection failure. A pipe dream? Too much to ask? Actually, now that Chrome has finally fixed its negotiationneeded event, this almost works! But you’re not using it, because “almost” doesn’t cut it. It only works 95% of the time, and the stakes from glare are too high in Chrome (no way to roll back from it, just pc.close()). But this original promise of the API is still within reach. We just need browsers other than Firefox to implement rollback, and fix some glaring (no pun intended) races in a few methods in the specification.

Perhaps few things in the WebRTC API cause as many pilot errors as the asymmetric exchange of SDP and ICE. Its stateful signalingState and timing sensitive ICE trickling can be a source of races if programmed incorrectly. As if that’s not challenging enough, keeping the two sides in sync and the two directions apart throws a lot of people for a loop (more puns).

What if I told you we can tame this complexity? That the manual way most people go about negotiating in WebRTC today is inferior, and possibly racy?

I’m talking about negotiationneeded and "rollback". Two mechanisms that can be used in concert to abstract negotiation away entirely. Yet, no-one is using them, because they haven’t worked, and don’t work yet in Chrome, respectively. We’ll introduce both. (more…)

August 6, 2018

isRemote in getStats() will disappear in Firefox 66

Contributed by Jan-Ivar Bruaroey,

Are you using getStats() for remote statistics in Firefox? Look for this warning today in Firefox Nightly (63, not 66):

⚠ Detected soon-to-break getStats() use! stat.isRemote goes away in Firefox 66, but won’t warn there!

TL;DR: If you see this warning in web console, read on to act now. Firefox 66 will move remote stats to "remote-outbound-rtp" and "remote-inbound-rtp", and isRemote will disappear, to comply with a change to the spec.

Firefox 63-65 will warn about this, but for technical reasons Firefox 66 will not be able to. This is because once the stats move in 66, there’s really no way to detect that you intended to look for remote stats the old way.

Update: The original article said Firefox 55. We’ve pushed it back to Firefox 66, giving you a little more time!


July 12, 2018

getDisplayMedia now available in adapter.js

Contributed by Philipp Hancke, doing things webrtc at

If you ever had a meeting over video and wanted to present some slides, there is a high chance you have used screen-sharing to do so. The WebRTC specification recently converged on a standard way to accomplish this. It took a fairly long time, because the security considerations for a web page accessing the pixels of your entire screen or another window are quite serious.

Browsers are actively implementing the standard getDisplayMedia API now, with Microsoft Edge being the first to ship a native implementation. You can track the current implementation status for Firefox, Chrome, Microsoft Edge and Safari.

Both Chrome and Firefox have long supported screen-sharing using slightly different and non-standard APIs. A couple of weeks back, Harald Alvestrand at Google asked whether it was possible to polyfill navigator.mediaDevices.getDisplayMedia for screen-sharing in adapter.js.

Update 11/17/18: getDisplayMedia used to live on navigator but was recently moved to navigator.mediaDevices.getDisplayMedia. Examples and adapter.js have been updated to match.


July 2, 2018

How to avoid Data Channel breaking

Contributed by Nils Ohlmeier, Hacking on real time communications since 2002

All the browser with support for negotiating data channels via SDP are using the same format. But the format is based on a specification from 2013. Since the specification has changed a lot since then it’s time to update the implementations to meet the latest spec.

Current status

If you are negotiating a data channel today in Firefox 61 (or current Chrome release) the SDP will looks something this:


July 2, 2018

New Tool for Debugging WebRTC

Contributed by Michael Froman, crossing IP communication streams since 2005

Debugging WebRTC? Ever wanted a bit more visibility into the flow of a WebRTC call?  Or see exactly what PeerConnection API calls were made and when? Have we got a debugging deal (dev tools plugin) for you! Go here or search for “dev tools media panel” on about:addons.

Getting Started

After loading the plugin and starting a call on, for example,, open the dev tools (Tools -> Web Developer -> Toggle Tools).  Next, click on the “Media-Webrtc” pane.  The “Media-Webrtc” pane is most likely at the far right. Finally, selecting the Webrtc tab shows something like:

May 22, 2018

Firefox is now supported by Google Hangouts and Meet

Contributed by Nils Ohlmeier, Hacking on real time communications since 2002

After extensive work from the Google Hangouts team and the Firefox WebRTC team both, the consumer version Google Hangouts and the enterprise version Google Meet, are working in Firefox with no plugin required thanks to WebRTC!

How we got here

Turning off the NPAPI  support in Firefox 53 resulted in the Google Hangouts plugin not working anymore. Unfortunately that meant that Firefox users could no longer enjoy Google Hangouts or Meet.

Google Chrome users could continue to use Hangouts and Meet without a NPAPI plugin, because the Google Hangout backend service had support for a flavor of WebRTC only implemented in Google Chrome. But that version was not spec compliant and was thus never supported by Firefox.

It took a considerable amount of effort from the Google Hangouts team to update their backend service to the latest version of the WebRTC specs to support Firefox. At the same time the Firefox WebRTC team implemented a bunch of features to support large scale conferencing for Google Meet.

In fact Google Hangouts, the consumer version, started working with Firefox 56. Now with Firefox 60 we were able to ship all the required features to also support Google Meet.

Thanks to all the hard working people involved in this project and resulting in making the Open Web a better and safer place from today on!

May 9, 2018

Better privacy on camera mute in Firefox 60

Contributed by Jan-Ivar Bruaroey,

On a web conference call, have you ever wondered if people can see you? Maybe you’ve tried to decipher the site’s video-mute button, often some red camera symbol with a slash through it—“Is it on or off? Does red mean stop or live? Is the slash telling me I’m muted now, or to click here to mute?”—All the while the camera light at the top of your laptop keeps glaring at you brightly.

We have fixed this in Firefox 60.

We can’t fix the websites, but in Firefox 60, whenever you video-mute, your laptop or USB camera hardware light will now extinguish. Whenever you unmute again, it will light back up. No more worrying if you’re live! (more…)