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I would suggest against a one-to-many architecture where a single device needs to send its media to all others. This breaks awfully fast (like after 2-3 devices it needs to connect to).

The reason for that is that uplinks are usually limited in capacity and even when they aren't, devices aren't really geared to streaming so much data to many other devices.

To do what you want at "scale", use a server component that routes media to the other devices. Look at https://jitsi.org/ and http://www.kurento.org/ for starting points.