Ring can be configured to use TURN or STUN servers (RFC5766 <https://tools.ietf.org/html/rfc5766>_) to establish a connection between two peers.
In this guide, we will setup a coturn <https://github.com/coturn/coturn>_ server. There are other TURN/STUN server implementations available under a free license. See TurnServer <http://turnserver.sourceforge.net/>_ and Restund <http://www.creytiv.com/restund.html>_.
COTURN is available in most Linux distributions. On Debian, install it with the following command: