Apache throughput problem with high latency client (WAN) on Windows 2000
I've got a problem with an Apache 1.3.33 installation on
windows 2000 related to throughput, I can't understand what is
When I request a file from the local lan, the throughput is
good and quite full, but when I fetch file from the internet (
we have a 180 KB/s link ) using clients with latency in
average around 100ms, the total througput seems capped and
limited to 40 KB/s .
If I use the same client and I fetch the same file using the
FTP protocol, I get full bandwidth usage ( 160-170 KB/s ).
If I fetch the same file from an instance of IIS installed on
the same server and same tcp port, the throughput is full,
like FTP ( 160-170 KB/s ).
If I fetch the same file from an instance of Apache version 2
installed on the same server and tcp port, the throughput
seems again limited, but bigger than 1.3.33 ( 90 KB / s ).
The file in question is 10 MB big.
So according to this tests, to me it is not an ethernet interface
problem, nor a wrong configured tcp ip settings, nor an
in-path router/firewall that do bandwidth limiting.
The only conclusion that I can make is that it seems that
Apache sets or force the trasmit tcp window (not honoring
client declared receive window, or host setting ) in some limiting way so
on high latency clients the problem shows up ( but not on
local lan ethernet where latency is very low ).
It is a known problem / how can I avoid the problem?