I run PCLOS minime on 3 machines at two locations: my notebook, a home desktop, and a work desktop.

Both home and work have DSL broadband

At home using the home desktop (wired) and the notebook (wired or wireless) both machines have good network performance: greater than 80kb/sec when both downloading from a remote server over the DSL connection.

At work, the work desktop has similar performance, but the same notebook starts at about 15K/sec and gradually over a few seconds slows down to about 2Kb/sec. This happens both over the wired and wireless connection.

Using the notebook to copy or download from a server at my workplace (e.g. the work desktop machine) it is very fast (up to the the local network bandwidth)

I ruled out:

- The HW (since the notebook works fine at home)
- The OS (since the desktop machine at work running PCLOS works fine)
- The network's physical layer (copying between the machines at work is fine)

So perhaps the firewall/router at work is the culprit? It is a SonicWall 300. But how come it only affects the notebook?

Running wireshark simultaneously both on my notebook and the work desktop , while both download from a remote server (i.e. synaptic server, my home server) the desktop download speed is at 80Kb/sec and my notebook is at 2Kb/sec. I don't see any unusual output in the notebook's wireshark output as compared to the desktop's wireshark output.

This issue has been going like this for months.

I am looking for ideas as to how to instrument, troubleshoot this problem.

The only things that come to mind quickly are 1-routing problem, 2-dns problem. Are you or do you have access to the admin of the router?
Good luck. ;-)

Thanks!

Yes I o have access to the router.

DNS should not be a a factor after the initial connection (e.g. when using wget to download)

I thought the router might not like my card so I spoofed the MAC address (using MACADDR in ifcfg-eth0) and also assgined a different static ip address to the notebook. It did not make any difference.

So the notebook is using static ip's in both locales? Does the same behavior occur if using dhcp? There could be limited connectivity if the route is the problem. I've seen stranger things occur. ;-)
Good luck. ;-)

found out that if I run firefox on windows xp that is running in qemu on the same machine, download speed is at almost full bandwidth

at the same time if i run firefox directly on the machine linux os, download speed is dismal.

somehow the network performance in winxp running in an emulator is much better than the network performance of the native interface on the same machine.

again, all this happen only at my workplace when connecting to external sites through a Cisco sonicwall

at home both setups perform well.

I am puzzled

Do you have ipv6 enabled or disabled in firefox? Check about:config look for this option That option will be boolean true or false. Just a guess but, if that is false try toggling it to true and see if that makes a difference.

One other question, since you've downloaded from both os's, were you downloading the same things from the same sites?
Good luck. ;-)

Solved

in /etc/sysctl.conf add

# ocilent1 fix for win_scale issue
net.ipv4.tcp_window_scaling=0

the above works for PcLinuxOS other distros may use

net.ipv4.tcp_default_win_scale = 0