Re: Question Regarding TCPWindowsize on W2K

2001-12-12 18:20:56
Subject: Re: Question Regarding TCPWindowsize on W2K
From: Cameron McDonald <cameronm AT IBK.COM DOT AU>
Date: Thu, 13 Dec 2001 11:18:08 +1100
My understanding is that Win2K will still come shipped by default to only
use a tcpwindow size of 64k.  Although NT4 couldn't comply with RFC1323
which allowed for larger sliding windows, W2K can.  To do this however you
will need to "edit the registry".  You then could change the setting in
TSM expecting it to work.

I have not actually done this but there are many references to changing
the TCP windowsize in W2k for larger packet size networks.  My suggestion
is to go to google and search for "windows 2000 tcpwindowsize rfc1323".
There are microsoft knowledgebase articles discussing this as well as
other heplful articles put together by users.

You will need to ensure that the AIX TSM server also has RFC1323 enabled
and a larger TCP windowsize for this to most benefit you.  Changing the
settings in TSM and not the OS is fulile :-)


On Wed, 12 Dec 2001, Steven Chaba wrote:

> >From one of my WinTel gurus:
> ----- Forwarded by Steven Chaba/RG&E on 12/12/01 11:18 AM -----
>                     John Wiersma
>                                          To:     Steven Chaba/RG&[email protected]&E
>                     12/12/01             cc:
>                     11:01 AM             Subject:     please post to
> I run TSM 4.1 on an AIX server with NT and 2000 clients.
> I have a question regarding TCPWindowSize on Windows 2000 Server.
> I was advised to set this parameter to 128 on Windows 2000 machines.
> When I do that, this shows up in the dsmerror.log:
> "The TCP window size 128K is not supported by your system. It will be set
> to the allowed size - 63K."
> My consultant says he has not seen this.
> Also, when I run the client on 2000 Professional, I do not have this issue.
> Anyone else seen this? Any advice?
> Thanks,
> John Wiersma
> Senior Network Analyst
> Rochester Gas & Electric Corporation
> john_wiersma AT rge DOT com
> (585) 724-8053