Your PMoD isn’t done with you yet. Now they want more than two people in the same conference. The problem is: as you add people to a conference, you’re going to run into the handshake problem. Basically, as you add more people, the number of connections will be dictated by:

So if you have four people, that’s 4(4–1)/2, or six connections. Going to eight suddenly means you have 8(8–1)/2, or twenty eight connections. Your PMoD thinks ten sounds good; that puts you at 45 connections to be established, worst case scenario.

Sadly, this won’t scale. At ten people, each person in the room has to push data to nine other participants. Most people lack the upstream bandwidth to do this. You’ve got a Real Problem™.

So how do we get around this? We use a Selective Forwarding Unit (SFU), a Multi-point Control Unit (MCU), or you tell your PMoD they’re on drugs and you can support four (maybe five??) people in a P2P full mesh of doom:

Of course, suddenly you need infrastructure — a lot of it, and likely redundant in case some server dies. And that server needs to be rock solid, since it’s a single point of failure for a conference. And you likely need it deployed all around the world, because there’s a serious latency penalty for a user in Australia trying to connect to your media server in the eastern United States. And that infrastructure is going to have to work with your TURN servers. And you need to make a decision about SFU or MCU, both of which have really distinct tradeoffs.