Bengtarn,
We own and operate nLayer Communications, so we largely run our own network.
For the traffic we do not peer directly, we buy transit from Level3, and Globalcrossing.
http://www.fixedorbit.com/AS/4/AS4436.htm
http://www.fixedorbit.com/AS/23/AS23352.htm
Those our are two transit ASN's, which do show the majority of our connections/peering.
You can also check out
http://anycast.reflected.net to both trace to, and get traceroutes back to whichever location you like. The Chicago location is where our dedicated/managed services are located.
Regards!
-Phil