Firefox fails to gather UDP ICE candidates during ICE restart(network switch)

[shazzzzzzzz]

Hi all,

I am trying out ICE restart scenario on Firefox and here is the description

- User A calls User B(both users are on same machine)
- Machine switches to new wlan(say wlan0 to wlan1)
- ICE connection state transitions to 'disconnected' for both users
- User A triggers renegotiation with ICE restart. Only TCP ICE candidates are gathered and call fails eventually

If the ICE restart is triggered without network interface switch, then Firefox gathers UDP ICE candidates as well and the call works fine.

The issue can be easily reproduced with WebRTC sample - https://webrtc.github.io/samples/src/content/peerconnection/restart-ice/

Tested on
- Firefox 67.0.1 (64-bit) on Open Suse Leap 42.3 - Fails
- Firefox 67.0.2 (64-bit) on Windows 10 - Fails
- Chrome 74.0.3729.169 (64-bit) - Works

Can anyone confirm if this is issue from Firefox or if there is something wrong with my scenario!

Thanks!

[Nils Ohlmeier]

Hello,

Yes this is a known problem. Firefox currently doesn’t take new interfaces into account. Neither automatically nor through ICE restarts.
We have an open bug for it somewhere in bugzilla. I’m not sure when we are going to fix it.

Best
Nils Ohlmeier

[Michael Froman]

This is the open bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1548318

-Michael.

[shazzzzzzzz]

Hi Michael, Nils,

Thanks for your quick response. I had posted the same question one year back in "discuss-webrtc" group and I had not got any response. So I guess this never worked.

Given that the call continuity during network switch is one of the top most use cases of ICE RESTARTS, I am curious as to why this bug is not prioritized?