[jitsi-dev] ICE failed and no relay found

Dear Jitsi Developers,

we faces problem ICE failure during perform voip /desktop sharing feature.
some literature give option to add relay server on xmpp feature.

then i add relay server on global relay van-xmpp1.globalrelay.net , but the
problem still the same as capture below.
Please help, how to solve the problem?

thanks in advance

Best Regards,