[c-nsp] FTP Throughput

[Joseph Mays]

Running tests on FTP throughput from a windows ftp client across two T3 hops 
to an ftp server running on FreeBSD unix. Pretty much all the bandwidth on 
both T3's is available. Total latency averages about 3ms. The customer on 
the end of the t3 is complaining that they can't get faster than 600KB per 
second anywhere. I get about 1000KB (8mbps) on a file transfer. I can start 
multiple file transfers, simultaneously, all top out at about that speed. 
The customer is demanding to know why they can't transfer files at, say, 
40mbps. I am assuming the answer is something to do with TCP window size, 
but how do I prove that?

Joe