I think that's the whole point of firewalls, to control incoming and outgoing connections. So peer-to-peer sometimes is simply impossible. TURN actually is just

I think that's the whole point of firewalls, to control incoming and outgoing connections. So peer-to-peer sometimes is simply impossible. TURN actually is just a proxy as far as I know so it's not p2p. That's why BitTorrent asks to open specific ports in your router, because otherwise you simply can't do p2p.