HTTP port forwarding is extremely slow

[j_f_d]

I have a NAT to forward HTTP traffic to a web server, and it is extraordinarily slow. Sometimes, downloading a file from 'outer world' hangs after 100 k.

The web server itself works fine (tested on LAN, it is damn fast)

The pfsense box is a 1.6 GHz Atom with 1 MB RAM, and for the moment only handles limited traffic. CPU is at about 5-10%.
It is on ADSL (1 MBps upload by contract, but tests show it is only 400 kBps)
I have enabled device polling to check: no improvement.
Traffic shaping is disabled.
Snort is turned off.
I have allowed ICMP for MTU discovery: no effect.

I have set MTU of web server to 1492 bytes, just to be sure. Did not chaneg anything.

If anyone has an idea, I would be grateful.

I suspect ADSL uplink, but uploading files from LAN to Internet is OK (although quite slow)

J-F

[Eugene]

Can you post screenshot of "NAT to forward HTTP traffic to a web server" here?