Peer to peer doesn't really work for group video calls, like more than 5 or so participants. As n goes up, each peer is sending n video/audio streams and receiv

Peer to peer doesn't really work for group video calls, like more than 5 or so participants. As n goes up, each peer is sending n video/audio streams and receiving n video/audio streams. This will quickly saturate your/your peers network and burden your CPU doing video encoding. Suffice it to say there are other things you can do besides just a central relaying server, but it's the most common architecture.