----- Original Message ----- 
From: "Peter Graf" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Monday, September 08, 2003 12:05 AM
Subject: Re: [ql-developers] Massive amount of job state transitions and
re-scheduling


>
> BRANE wrote:
>
>  >> Simple example: A M$ or Unix machine sends a file to the QDOS machine
via
> > > TCP. It will send one or two packets, then stop and wait for ACK.
Further
> > > packets will only be sent after further ACKs. Your ACKs can only be
> > > generated in 50 Hz rhythm, so packets will crawl one-by-one in 50 Hz
> > > rhythm. (Or two-by-two, if you're lucky.)
> >
> >AFAIK with TCP/IP this is negotiable. There is no need for such small
> >window...
>
> QLwIP offers a window of 8760, but I have found that neither Windows nor
> Linux will exploit that in their standard configuration, at least not as
> long as their counterpart has 20 ms latency. Depending on the application,
> they send one, maximum two packets before they wait for ACK.
>
> Somehow QLwIP must live with standard behaviour of other machines, you can
> not expect people to tune their TCP stacks.
>
> All the best
> Peter

Hmm. Something doesn't sound right here. Internet is full of "speed up your
Internet connection" programs that do amongst other things exactly this, so
I presume this has to be negotiable.

Besides, I find it a bit hard to believe that average PC does acknowledge
every packet on 100 Mbit Ethernet.  This would mean something like
interrupts with 100 kHz rate. Not very likely on modern machines...

This would also make TCP/IP on 1Gbit Ethernet useless...

 Regards,


Branko

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