> packets must arrive within ~40us (that's us, not ms) of their allotted time, something very difficult to reach in software. (I will be talking about this at demuxed next week...)
Maybe in Ethernet-land, but this is trivially achievable (actually exceeded by more than an order of magnitude) with off-the-shelf Infiniband gear that is available for peanuts these days. Actually it's close to two orders of magnitude if you want to shell out for the latest gear.