Firefox 63.0+ missing BUNDLE attribute on SDP offer results in failure on setLocalDescription

[Eric Green]

If you try and set up a call to Firefox 63.0+ without including an a=group:BUNDLE attribute in the SDP Firefox will fail to set the local description that it generated.

I have created a small demo of this application on Github (https://github.com/egreenmachine/no-bundle-failure) which can be viewed live at https://egreenmachine.github.io/no-bundle-failure/. You can see the error messages on the web console.

FF63+ fails with DOMException: "Local descriptions must have a=mid attributes.". I believe that you cannot have a=mid attributes without having groups.

This will work in FF62, and Chrome 69.0.3497.100. I understand that the peer connection will not complete with the SDP provided because it is stale, but it should still be able to set the local SDP that is generated from the offer. The SDP was generated using RTPEngine. I can also demo this same behavior with a live system if needed.

The question is, should FF63 be failing here or is this a regression? There are lots of endpoints out there that do not currently support bundled sdp, so I believe if it is released in this state it will break lots of users.

Thanks,
-Eric Green

[Byron Campen]

On 10/16/18 2:35 PM, Eric Green wrote:
> If you try and set up a call to Firefox 63.0+ without including an a=group:BUNDLE attribute in the SDP Firefox will fail to set the local description that it generated.
>
> I have created a small demo of this application on Github (https://github.com/egreenmachine/no-bundle-failure) which can be viewed live at https://egreenmachine.github.io/no-bundle-failure/. You can see the error messages on the web console.
>
> FF63+ fails with DOMException: "Local descriptions must have a=mid attributes.". I believe that you cannot have a=mid attributes without having groups.

    This is not the case. mid attributes are used for more than bundle
grouping. We used to be more tolerant of missing mids in remote
descriptions, but we're working on that over here:
https://bugzilla.mozilla.org/show_bug.cgi?id=1495569

    In the meantime, just put mids in your SDP, because mids are
crucially important to the latest RTCRtpTransceiver-based specifications.

Best regards,
Byron Campen

[Eric Green]

Hi Byron,

Thanks for the quick response. I have added that hack to the SIP.js library and it looks to resolve our issue for now. I will work on updating our media servers as well to include them by default.

-Eric Green

[domnic...@gmail.com]

Hi, could you please write, what hack do you added ?

[39...@ismoman.com]