For what it is worth, check out
http://www.patents.i bm. com/cgi-bin/viewpat.cmd/US06009081__
This should better explain how InterNap has massaged their routing tables in the past.
With the release of ASsimilitor 3.0(?), they will be performing real-time data manipulation. Previous to this revision to their software, updates to the routing tables were occuring once every twelve hours, I believe.