“With the advent of WebRTC, web app developers gained the ability to exchange high quality voice and video calls – but no standard way to actually route the calls.
Matrix is the missing signalling layer for WebRTC. If you are building VoIP into your app, or want to expose your existing VoIP app to a wider audience, building on Matrix’s SDKs and bridges should be a no-brainer.“¹
For video conferencing, distinguished from point to point calls mentioned above, Matrix clients currently use the Jitsi protocol, automatically generating and sharing a random Jitsi room name. This prevents attackers from guessing the room and joining. Users just click on the phone or camera in a multi-user room to create a conference for all the room participants.
It is not clear whether jitsi conferencing is end to end encrypted yet; they have been working on it. Self hosting a Jitsi server is one way to solve this issue. This is harder than a Matrix server, but is certainly doable and there are commercial companies offering to consult on hosting your own or host it for you, with an improvement in privacy compared to using a free public access server like https://meet.jit.si/
Matrix provides secure, end to end encrypted voice and video calls for all users as well as video conferencing. Most Matrix clients support VOIP. Just click the phone or camera icon.
¹ See VoIP on https://matrix.org