If you run "make" in the papers/IBIC2013 directory you'll get this paper: https://cds.cern.ch/record/1743073/files/thbl2.pdf

It's quite interesting - this isn't ethernet as we know it. Instead of each NIC using its own free-running clock, all the physical layers are sync'ed to each other at layer 1. (note that gigabit ethernet, which is what it uses, sends data at all times - when idle it sends the idle symbol)