Coturn is a libre STUN and TURN server software that allows users of internet applications or protocols (Such as XMPP and Matrix) to perform WebRTC voice and video calls despite them being behind NATs. If you want to add video and voice calling natively to your XMPP or Matrix server (or a myriad of various other applications), you’ll need to install Coturn and configure it appropriately. Note on ejabberd If you’re installing ejabberd, then you don’t need Coturn.
