Coturn for WebRTC NAT Traversal13. Jun, 2020
This article will show you how to set up Coturn. This is a service that allows hosts behind NAT to communicate peer to peer with webrtc. STUN is helping to negotiate port/ip and TURN will proxy the actual traffic if all else fails.
We're using this with Convos' video IRC feature, but the same applies to other WebRTC projects.
I'll be assuming you're on Ubutunu for this tutorial, so users on other distros will have to adjust the setup for their environment. First we'll install the actual ubuntu package. If you don't already have it, you will also need letsencrypt to generate valid ssl certs.
apt-install coturn certbot
Then we edit
/etc/turnserver.conf - It should look roughly like this:
listening-port=3478 tls-listening-port=5349 listening-ip=<server public interface> relay-ip=<IP used for relaying> external-ip=<actual external IP> realm=example.org server-name=coturn.example.org fingerprint lt-cred-mech user username:s3cret cert=/etc/letsencrypt/live/coturn.example.org/fullchain.pem pkey=/etc/letsencrypt/live/coturn.example.org/privkey.pem cipher-list="ECDH+AESGCM:ECDH+CHACHA20:DH+AESGCM:ECDH+AES256:DH+AES256:ECDH+AES128:DH+AES:RSA+AESGCM:RSA+AES:!aNULL:!MD5:!DSS"
Set up letsencrypt
$ sudo certbot certonly --standalone --preferred-challenges http \ --deploy-hook "systemctl restart coturn" \ -d coturn.example.com
certbort will automatically set up renewal of the certificate
Now let's enable the service. Add
TURNSERVER_ENABLED=1 to /etc/default/coturn and then
systemctl start coturn.
To use such a server with Convos, it requires a couple of environment variables to be set:
Environment=CONVOS_STUN=stun://user:[email protected]:5349 Environment=CONVOS_TURN=turn://user:[email protected]:5349
(Assuming you run Convos under systemd)
systemctl daemon-reload and
restart after updating the service :)
If you're running Convos a different way like under Docker, adjust the relevant settings.