beware. six is funny. it's in seattle's carrier hotel, the westin, 32 floors of racks, more colo providers than fleas on a dawg, and very very low inter-suite fiber rates from the building owners. so, though the six does have a core, it is also kinda splattered into switches all over the building; with ease of connection and low cost being achieved at the expense of reliability. and costs are distributed along with the six infrastructure. so colo provider A may have a switch and charge $a to access it, while colo provider B may charge $b, where $b != $a. for a small local exchange this is ok, even cool. i would not want to do similarly in virginmania or palo attitude, and i would not join the six if i was a major player (only a research rack is on the six). my internal indirect costs would not be worth the traffic shed. randy