TURN service validation
Install package coturn (and stop and disable the service if unneeded).
Simple test anonymous insecure STUN service:
turnutils_stunclient -f turn1.debian.net
(seems that if it hangs, it is the server offering a bogus secondary IP)
Test anonymous insecure STUN service (udp and tcp:
turnutils_uclient turn1.debian.net -y
turnutils_uclient turn1.debian.net -t -y
(check for packet loss)
Alternatives STUN/TURN validation:
https://stackoverflow.com/questions/28772212/stun-turn-server-connectivity-test
STUN/TURN validation service:
https://webrtc.github.io/samples/src/content/peerconnection/trickle-ice/
https://ip8.com/webrtc-test
https://testrtc.com/
https://networktest.twilio.com/
Public STUN/TURN services:
https://github.com/DamonOehlman/freeice#current-list-of-servers
Nice explanation of turnutils_stunclient:
https://gist.github.com/cameron-elliott/be1e581cb7b28f748e04bcabc249e6b6
TURN service REST interface
https://stackoverflow.com/questions/35766382/coturn-how-to-use-turn-rest-api
