NAT has been around for twenty years now, so there's no excuse for having anything less than robust, any-direction-any-path in every new protocol. I'm honestly more than a bit disappointed that WebRTC has pushed this down into the application leaving every application to work it out for itself.
The smart thing to do would have been to make the signalling layer use IPv6 and insist on configured 6in4-configured gateways (or similar).
The smart thing to do would have been to make the signalling layer use IPv6 and insist on configured 6in4-configured gateways (or similar).