thisismissem, The untold story: how the PIX changed the internet — https://youtube.com/watch?v=GLrfqtf4txw&feature=share
This was a really neat watch, and when I think about it, I've a gut feeling that the #Fediverse is in it's pre-NAT era, where every instance is directly connected. I think in the future we'll see a shift towards relays to power many many more instances on the network, reducing the overall connectivity required for instances.