Subject: nt to nt tcpsat problems

From: Graham Street <[email-masked]>
Date: Thu, 10 Feb 2000 09:04:04 -0500

Hi all,

We're trying to run windows file sharing protocols over a tcp sat link
and getting miserable performance, even after setting TcpWindowSize to
65536.   We can get about 100-250k max.  We are trying to get at least
one megabit out of it.  Is this even possible?  We can get 1-2 megabits
ftping from a sun box over satellite...

does anyone know of any clever (cheap) solutions  (spoofing nacks?, translating 
to udp?)

Thanks,
Graham Street
[email-masked]

---

From: "Robert Schellhase" <[email-masked]>
Date: Thu, 10 Feb 2000 14:18:06 -0500

Hi Graham,
I see you have found that Windows supports a registry key for TcpWindowSize.
The sad news is that it has no effect, in spite of the fact that Microsoft
has a white paper on its own TCP implementation that claims otherwise.

You might try the NetManage OnNet kernel for Windows 95/98 at
http://www.netmanage.com/products/onnetkernel4/index.asp

I don't know what they charge for it, but I think it's affordable and they
offer a free demo.

Best regards,
Robert Schellhase
Senior Engineer
INTELSAT

-----Original Message-----
From: [email-masked] [mailto:[email-masked]]On
Behalf Of Graham Street
Sent: Thursday, February 10, 2000 9:04 AM
To: [email-masked]
Subject: nt to nt tcpsat problems

Hi all,

does anyone know of any clever (cheap) solutions  (spoofing nacks?,
translating
to udp?)

Thanks,
Graham Street
[email-masked]

---

From: "Greg Otto" <[email-masked]>
Date: Thu, 10 Feb 2000 18:04:20 -0600

Gentlemen,

I did a week long study on this exact problem and the simple answer is "YOU
ARE OUT OF LUCK."  I have a ticket open with MS on this problem as it is how
the CIFS protocol works.  CIFS will only negotiate a 4K transfer size when
the latency and bandwidth are small (if you are very very ... lucky maybe
upto 12K).  Basically, in short your throughput will be about equal to
4K/RTT (excluding other various factors).  Thus, window size only needs to
be 4K for this.  It is a higher layer problem!!!

While I cannot give you a copy of my report,  I do have a couple of graphs I
can get to you.

Greg

-----Original Message-----
From: [email-masked] [mailto:[email-masked]]On
Behalf Of Robert Schellhase
Sent: Thursday, February 10, 2000 1:18 PM
To: [email-masked]
Cc: [email-masked]
Subject: RE: nt to nt tcpsat problems

Hi Graham,

Best regards,
Robert Schellhase
Senior Engineer
INTELSAT

-----Original Message-----

Hi all,

Thanks,
Graham Street
[email-masked]

---

From: "Noam Gonnen - Israel" <[email-masked]>
Date: Fri, 11 Feb 2000 03:02:06 +0200

Graham,
1) regarding the IPstack and services white paper from MS, for what ever
it's worth (concidering what Robert has said), you can find the NT versions
(3.51->5) on http://vipe.technion.ac.il/~noamg , including all relevant
Reg.Keys etc.

2) You may also want to check with :
 2.1) Flash Networks (prod=SatBooster) on http://www.flash-networks.com/,
application level spoofing (proxy)
 2.2) Fourelle (prod.=Venturi) , uses similar principal, on
http://www.fourelle.com/

Sincerely,
 Noam Gonnen
 Gilat Satellite Networks LTD. (http://www.gilat.com)
 Email: [email-masked]  Email2: [email-masked]