I suggest you take some traces using tcpdump and analyze them using
tcptrace and XPLOT. Also, what is the file size being transferred? If it
is small, slow start may be dominating (or at least effecting) your
throughput calculations. Finally, what are the characteristics of the link
(BER, fade, etc...) and what are the congestion characteristics? Tracing
the transfer should help give a sense of what is happening.
At 01:55 PM 11/13/98 +0100, [email protected] wrote:
>
>
>
>Hi Jack,
>
>Couple more details :
>- we have an inroute of 128 kbps and an outroute of 512kps.
>- ftp traffic is carried over Transaction Reservation on VSAT
>
>Doing an ftp , I get 30 kps on the outroute and less on the inroute (19
>kps). Although I'm not the only user on the VSAT network, I expected a
>higher performance (the usage is only 20 % on inroute and 30 % on
>outroute).
>
>Best regards,
>Guy
>
>
>
>
>
>
>
>Dear Guy,
>
>What do you expect,
>and what do you get as performance?
>
>
>Jack Stiekema
>
>Cap Gemini Nederland
>Phone: +31 (0)30 252 9219
>Fax: +31 (0)598 398008
>
> -----Original Message-----
> From: [email protected] <[email protected]>
> To: Dave, Kamal N <[email protected]>
> Cc: [email protected] <[email protected]>
> Date: vrijdag 13 november 1998 12:01
> Subject: RE: TCP over VSAT
>
>
>
>
>
> Hi Dave,
>
> We are using also Hughes systems : PES6000, ISBN 7.B (soon 7.D). Our
> problem is that TCP is not performing very well over this network,
>although
> we are using NT with SP3 (which includes Fast retransmission/recovery)
>and
> on the host Solaris 2.6 which also support this. Reading a lot of
> documents, the above techniques are presented as the solution for the
> TCP/VSAT problem (if I understand correctly). My question is : are
>there
> any other techniques/ method's that improve TCP/VSAT ?
>
> Thanks,
> Guy Raymakers
> EDS
>
> PS.: the window size is 40880, and some timing parameters are also
>changed.
>
>
>
>
>
>
> Hi:
>
> We are using Hughes Network Systems VSAT in 13 countries. We have a
>Unix
> based system, but soon we will be moving to NT. Specifically what do
>you
> want to know ?
>
> Kamal Dave
> Galaxy latin America (Sub. Hughes Electronics)
>
> -----Original Message-----
> From: [email protected] [mailto:[email protected]]On
> Behalf Of [email protected]
> Sent: Tuesday, November 10, 1998 5:01 AM
> To: [email protected]
> Subject: TCP over VSAT
>
>
>
> Hi ,
>
> Is there someone with experience about the following subject : TCP over
> VSAT ?
>
> We are using NT servers on the remotes and centrally SUN Solaris 2.3
> and
> 2.6 server.
>
> Many Thanks,
> Guy
>
>
>
>
>
>
>Attachment Converted: "h:\workarea\eudora\att-11.htm"
>
>Attachment Converted: "h:\workarea\eudora\Jack Stiekema2.vcf"
>
*********************************************
William D. Ivancic
NASA Lewis Research Center
21000 Brookpark Rd. MS 54-8
Cleveland, Ohio 44135
USA
Phone: 1 216 433 3494
FAX: 1 216 433 8705
Email: [email protected]
[email protected]
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