Re: Problems on windows

To: iperf-users --at-- dast.nlanr.net
Subject: Re: Problems on windows
From: Hans Blom <jblom --at-- science.uva.nl>
Date: Thu, 4 May 2006 11:04:41 +0200
Content-disposition: inline
Content-type: text/plain; charset=us-ascii
In-reply-to: <4457AA41.5060300@surfnet.nl>
References: <4457AA41.5060300@surfnet.nl>
Reply-to: iperf-users --at-- dast.nlanr.net
Sender: owner-iperf-users --at-- dast.nlanr.net
User-agent: Mutt/1.4.1i

Hi Maarten,

On Tue, May 02, 2006 at 08:51:45PM +0200, Maarten Koopmans wrote:
> Hi,
> 
> We are using iperf as one of the underlying tools in the SURFnet 
> Detective (detective.surfnet.nl) and I'm seeing some really strange 
> behaviour. In our setup we have a bunch of linux servers on 1 GBit, and 
> when testing from linux clients over the WAN we get between 300-800mbit 
> depending on how many threads, window size etc (using TCP).
> 
> Using iperf 2.01 on windows I don't get more than 20 mbit. Using the -P 
> option crashes that version. Nevermind, I downloaded version 2.02 based 
> on cygwin, and decided to test some more from home. Home is an ADSL2+ 
> connection 12mbit down, 1mbit up.

The maximum system allowed TCP window size under Windows may be limited. See
"http://www.psc.edu/networking/projects/tcptune/"; how to enlarge it for
Windows XP. If the default values are still valid that might limit single stream
TCP performance. If the max. TCP window sizes are fine you could try some UDP
tests. If they go well there could indeed be a TCP stack problem.

    Regards,
    Hans

References:
- Problems on windows
  - From: Maarten Koopmans

Prev by Date: Problems on windows
Next by Date: Re: Problems on windows
Previous by thread: Problems on windows
Next by thread: Re: Problems on windows

Other Mailing lists | Author Index | Date Index | Subject Index | Thread Index