Ungodly packet loss rates

   >One can certainly make the argument that running large traffic
   >flows through shared interconnects is bad engineering

   Yes, and I think the operative word is "shared" as in "shared
   access media".

Shared access to the media is not relevant. Scalability of the shared
media is. Private interconnects are simply more scalable than shared

It makes sound engineering sense that networks pushing heavy amounts
of traffic between each other would like to distribute that load
around their networks, rather than try to take it all at the public

The private interconnects are not necessarily modeled after the public
exchange points, but are really ds3 or higher speed circuits
positioned between NSP POPs in areas were both networks have good

If NSPs continue to build out their Networks to support the public
NAPs, they would have to deal with higher and higher amounts of
concentrated traffic in those areas. With private connects, NSPs can
distribute their load in less congested areas of their network.