Thanks for the detailed answer. The only technical understanding of a CDN I have is from CoralCDN (http://www.coralcdn.org/ http://www.coralcdn.org/), a p2p CDN

Thanks for the detailed answer. The only technical understanding of a CDN I have is from CoralCDN (http://www.coralcdn.org/ http://www.coralcdn.org/), a p2p CDN operated by researchers on PlanetLab (with servers all around the world) that was especially created to mitigate flash crowds scenario, and their very documentation on this experiment (http://www.coralcdn.org/pubs/ http://www.coralcdn.org/pubs/, particularly http://www.coralcdn.org/docs/coral-nsdi04.pdf http://www.coralcdn.org/docs/coral-nsdi04.pdf). I was impressed by how the nodes automagically coordinate themselves so that as few as possible will query upstream, and then content will be slowly propagated to other nodes that were requesting for this exact content in a form of multicast tree, all with 0 administration and thanks to a smart DHT and a smart DNS implementation. Really cool stuff. I was under the impression that any commercial CDN was doing at least the same.