From: Randall Parker 



Mike N. wrote:
> On Thu, 27 Jul 2006 21:36:00 -0400, Mike N.  wrote:
>
>>   I just tried turning off timestamps.   Still the same problem.  So now
>> the only thing left is Window Scale - the cause can still be DNews or
>> Win2000.
>
>   I tried turning off TCP/IP Window Scaling on Linux.   PRESTO - it worked!

When you said "it worked!" I figured you meant it sped up Linux
Thunderbird talking
to news.barkto.com, correct?

But George Sherwood asked how to do that you told him to do:

    echo -n 0 > /proc/sys/net/ipv4/tcp_timestamps

But later you told me:

    echo -n 0 > /proc/sys/net/ipv4/tcp_timestamps

    It has no effect on this problem.  They do make bigger packets by 12
bytes, but only for the ACKs which should have no impact on download speed.
In addition, the self-tuning TCPIP algorithms won't have as much
information to work from.


Okay, "this problem" means to me the slowness of Linux
Thunderbird with news.barkto.com.

So now I'm confused: Does turning of TCP/IP Window Scaling on Linux speed up Linux
Thunderbird talking to news.barkto.com? If so, how to turn off  TCP/IP
Window Scaling?

> Now that I have gotten this deep into it, I'd like to understand why.  I'll
> have to see what control DNews has over these parameters to see if there is
> any App interaction or if it is all confined to Win 2000.
>
>    Eventually, I may still need a Net Monitor dump from that end to
> eliminate some more things.
>
>
>  [footnote]
>    There was great controversy in the Linux team whether to take the
> Windows approach and work with maximum compatibility or move forward and
> provide full speed capability for those running a multi-megabyte line
> between continents.   They chose to move forward, regardless if routers
> supported it correctly or not.  That leads to situations like this.   They
> should have made it an option for those few brave pioneers with the
> multi-megabyte inter-continental connections, and make it just work in
> maximum compatibility for the rest of us.    I noticed that the window size
> even self-tuned nicely with Window Scaling disabled.

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