On 2010.04.29 17:31, Robert Enger - NANOG wrote: > 1) The capacity that a campus has into I2 or NLR is different than the > BW the campus purchases from their commercial provider(s).
> 2) The commercial BW test sites are not optimized for speed. They do > not have unlimited capacity network connections. And, they have not > tuned their network stack for HS operation: notably, their OS will > impose memory limits on the socket / transmit-buffer pool; so even if a > receiver advertises a big window, frequently the transmitter (speed test > server) will never queue enough data to fill the pipe > 3) Peering capacity is not what it should be into the networks used by > some of the BW test sites. Your observation is disturbingly bleak... do you have a recommendation? ...perhaps a site with good bandwidth and a cluster of iperf(1) boxes available? :) Steve
