This was the seminal paper. This 2008 paper is interesting too: http://ccr.sigcomm.org/online/files/p63-alfares.pdf http://ccr.sigcomm.org/online/files/p63-alfa

This was the seminal paper. This 2008 paper is interesting too: http://ccr.sigcomm.org/online/files/p63-alfares.pdf http://ccr.sigcomm.org/online/files/p63-alfares.pdf. In the cloud you could implement a fat-tree topology in software via something like Google's glcoud routing API (https://cloud.google.com/compute/docs/networking#routing https://cloud.google.com/compute/docs/networking#routing) or Open vSwitch (http://openvswitch.org http://openvswitch.org). NB: Tianhe-2 (Milky Way 2) -- listed number 1 on TOP500 (http://www.top500.org/lists/2015/11/ http://www.top500.org/lists/2015/11/) -- uses a fat-tree topology with 13 switches each of 576 ports (https://en.wikipedia.org/wiki/Tianhe-2 https://en.wikipedia.org/wiki/Tianhe-2).