data upload causes increase in CPU activity and network slowdouwn.

[Lorenzo Sandini]

Hi,

Very strange behaviour on my home computers here. I moved from Switzerland
to Finland and kept my same hardware, but recently I noticed my computers
got very hot when uploading data to remote servers, or when people were
downloading data from my servers.

I am using a standard P4-based homebuilt desktop PC and a Toshiba laptop,
both under XP SP2. Firewall is ZoneAlarm.

Each computer connects to a Linksys WAG54G ADSL modem/router, either
wirelessly or on a wired basis, tried both and problem is still there.
Connection is 512/512 kbps on a RFC 1483B ADSL connection, and computers are
fitted with either Linksys PCMCIA / PCI linksys WLAN adapters, and wired
network adapters, all configurations provide the same results.

Connection to router, to the internet, workgroup browsing, file and printer
sharing all work like they should. Issue is identical with / without
firewall.

Downloading from the internet, or receiving data on the FTP server works
fine. All incoming connections work fine indeed.

Problems arise when I am sending out data, either actively uploading data
from my home computer to a remote FTP server, or when people download data
from my HTTP server hosted on one of my machines at home. When I start
sending out data, the task manager notices an increase in the CPU cycles for
the process sending data (either ftp client, ftp server, apache server,
etc...), with CPU use finally reaching 100%. Similarly, the upload speed
comes slowly but steadily down from 55 kb/s to about 20 kb/s, and remains at
that value after that.

To be precise, both computers exhibit the same behaviour suddely, while all
was fine 6 weeks ago with the same hardware.

Virus and spyware scans tell me the machines are "clean", and all I can
think of is the firmware upgrade of the router, and I also flashed it back
to an older version without success.

Any suggestion ?

Thanks in advance
Lorenzo

 

[Lorenzo Sandini]

Hi,

Very strange behaviour on my home computers here. I moved from Switzerland
to Finland and kept my same hardware, but recently I noticed my computers
got very hot when uploading data to remote servers, or when people were
downloading data from my servers.

I am using a standard P4-based homebuilt desktop PC and a Toshiba laptop,
both under XP SP2. Firewall is ZoneAlarm.

Each computer connects to a Linksys WAG54G ADSL modem/router, either
wirelessly or on a wired basis, tried both and problem is still there.
Connection is 512/512 kbps on a RFC 1483B ADSL connection, and computers
are fitted with either Linksys PCMCIA / PCI linksys WLAN adapters, and
wired network adapters, all configurations provide the same results.

Connection to router, to the internet, workgroup browsing, file and
printer sharing all work like they should. Issue is identical with /
without firewall.

Downloading from the internet, or receiving data on the FTP server works
fine. All incoming connections work fine indeed.

Problems arise when I am sending out data, either actively uploading data
from my home computer to a remote FTP server, or when people download data
from my HTTP server hosted on one of my machines at home. When I start
sending out data, the task manager notices an increase in the CPU cycles
for the process sending data (either ftp client, ftp server, apache
server, etc...), with CPU use finally reaching 100%. Similarly, the upload
speed comes slowly but steadily down from 55 kb/s to about 20 kb/s, and
remains at that value after that.

To be precise, both computers exhibit the same behaviour suddely, while
all was fine 6 weeks ago with the same hardware.

Virus and spyware scans tell me the machines are "clean", and all I can
think of is the firmware upgrade of the router, and I also flashed it back
to an older version without success.

Any suggestion ?

Thanks in advance
Lorenzo

 

[Lorenzo Sandini]

I found Zonealarm was the cause of this.

Simply closing the firewall didn't cure the problem, but uninstalling the
software did it.

I installed a previous version (ZA Suite 51_033_000.exe) and it all works
fine. Re-installed the 55_062_004.exe (with junk mail filter...) and the
problem is there again, on both computers.

I am now going to ZoneLabs.com to see what they say about that.

Lorenzo