Not much, we use WebRTC and thus connections for video and audio are sent P2P between clients. You can introduce a TURN server to help take the load off of the P2P connections, they can also help in cases where P2P may not work or have issues with network routing.
SmarterMail just helps keep track of who is in what meeting and allows the peers to exchange p2p info with eachother. So you don't need to worry about bandwidth or load really.

That's excellent. Thank you!

Why doesnt the scheduled meetings populate to outlook calendar?