[kev009]

Most large operator datacenters are converging toward things like Clos and fat tree networks that provide abundant bandwidth at acceptable cost and with minimal blocking. Switch silicon vendors have really done yeoman's work pushing the envelope to make this possible and inexpensive. AWS might have such magnitude of machine count and generally low customer resource utilization that they can oversubscribe a lot, but it would be pretty silly to only bring in 200gbps to a rack post 2014 when the Broadcom Tomahawk switch ASIC became dominant.