So use a TURN server. TL;DR: Does the same as STUN but also is able to relay video & audio for hosts where STUN fails. I'm using it in a Android app of mine f

So use a TURN server. TL;DR: Does the same as STUN but also is able to relay video & audio for hosts where STUN fails. I'm using it in a Android app of mine for video conference and works really good. You can download something like coturn and drop it in a 5$ digitalocean and run with it. It works for me.