My comments are based on some tests that I ran a couple of weeks ago.
Latency between Stanford and MIT via the T3 NSFnet was much greater
than an equivalent path via CIX/Alternet (about 50% longer delay via
the NSFnet). The results were repeatable and consistent. Throughput
was also lower but I attribute that to the longer latency and limited
TCP window size.
The bottom line was that the performance as seen by a standard
workstation using standard networking tools was better via CIX. I
suspect that very large windows would push the throughput performance
in favor of the NSFnet but I do not have the tools right now to test
that.
Anybody have a TCP with large windows I can play with?
Brian Lloyd, WB6RQN Lloyd & Associates
Principal and Network Architect 3420 Sudbury Road
brian@lloyd.com Cameron Park, CA 95682
voice (916) 676-1147 -or- (415) 725-1392