ICE failing on T-Mobile / Mint Mobile

[corby-github]

A recent code change (on the server side) seems to have introduced some interesting ICE handshaking failures on behavior on T-Mobile / Mint Mobile (strangely only on iOS. Android works). (Yes, I know that sounds weird)

Here is what I know: using the same keeping the client (running the latest SDK): July 2 - ✓ works jitsi-meet_9584 Aug 1 - ⨉ broke jitsi-meet_9646 Oct 1 - ⨉ still broke jitsi-meet_9753

I think its related to this.

• We are not using TCP for ICE
• Everything seems to work on meet.jit.si (but that's not surprising)
• It appears that ICE candidate pairs are being send by iOS and received on the jvb
• Tested with JitsiMeetSDK v10.0.1 and v10.2.1

Another weird qwerk... I can join a meeting on Wi-Fi, establish the channels, then switch to mobile data and it will keep working. So It's not a straight 'UDP blocked by carrier' thing either. (besides it works fine on 9584)

More details to follow, but I wanted you to know I was researching this. Any pointers are appreciated!

[corby-github]

No code changes will be needed. This was unrelated to the Jitsi versions. We had some environmental changes that totally removed IPv6.

📌 Even though you may not utilize IPv6 addresses, the bridge should still listen on udp6 - There seems to be some mapping/translation happening on the system with IPv4->IPv6:

Reenabling IPv6 on the system resolves the T-Mobile/Mint mobile issue:

~: netstat -anpl | grep 10000
(Not all processes could be identified, non-owned process info
 will not be shown, you would have to be root to see it all.)
udp6       0      0 12x.1xx.78.84:10000     :::*                                -                   
udp6       0      0 12x.2xx.18.78:10000     :::*                                -