Weird upload performance problems with proftpd

[Bill Moran]

I'm having some really weird performance problems with proftpd-1.2.10 on
FreeBSD 4.10 (in a jail) that I just can't seem to figure out.

My uplink here maxes out at about 35k/sec.  If I scp to the machine in question
I get about 30k/sec (which is expected) but when I ftp, I never get anything
better than 15k/sec, and occasionally as low as 8k/sec.

Using a server colocated at another facility, I can ftp at about 45k/sec, and
scp at about 60k/sec.

Downloads are all as expected ... scp and ftp downloads seem to be in about
the same range, and it's a number I would expect.

I tried running the ftp daemon that ships with FreeBSD, and it exhibited the
same performance issues.

Most settings on this machine are at their defaults.  I've tried tweaking
send/recv sizes, as well as toggling delayed_ack.  None of these have
made any difference so far.

Suggestions?

-- 
Bill Moran
Potential Technologies
http://www.potentialtech.com