I'd like a good heuristic to use to detect if someone is likely behind a symmetric NAT or is blocking UDP packets without generating ICE candidates from a TURN server.
I tried the method explained here: https://webrtchacks.com/symmetric-nat/ but I'm not sure if that's still accurate as the test assumes the 2 STUN servers will return a single rPort from the SDP & when I test on various networks I always get 2 different rPorts (I'm assuming because now ICE candidates are fetched in parallel?)
Also curious on the easiest way to simulate a symmetric NAT. I tried connecting via an android hotspot, but that didn't work. I tried the SO solution here, but it didn't work on Ubuntu 18.04.
