You are right Luigi,
Ad far i could read the doc's they use a proprietry protocol (both ends have
a proxy).
Jack Stiekema
Cap Gemini Nederland
Phone: +31 (0)30 252 9219
Fax: +31 (0)598 398008
-----Original Message-----
From: Luigi Rizzo <[email protected]>
To: Aaron Falk <[email protected]>
Cc: [email protected] <[email protected]>
Date: zondag 25 oktober 1998 11:40
Subject: Re: Article on IP over Satellite
> Check out:
>
> http://www.satellitetoday.com/viaonline/issue/1098ip.htm
I find the following quote especially significant:
<about Mentat's Skyxpress (Skyx) Gateway System>
Skyx does not change how TCP works over the terrestrial portion
of the connection, nor does it break TCP's end-to-end semantics
unlike spoofing solutions, which artificially inject acknowledgements
into the TCP stream in order to attempt to speed up data
delivery," says DC Palter, Mentat's vice president for sales
and marketing.
...
average throughput, on a simulated forward link speed of 10
Mbps with a reverse link speed of 128 kbps ... In the case of
500 KB file, the Skyx delivery time is 2.2 seconds as opposed
to 36.1 seconds for TCP/IP.
2.2s amount to about 4RTTs, so either they use a proxy approach
(which is not different from "breaking e2e semantics and artificially
injecting acks"), or they start with an unreasonably large initial
window.
Once again, can you say "congestion control".
cheers
luigi
-----------------------------+--------------------------------------
Luigi Rizzo | Dip. di Ingegneria dell'Informazione
email: [email protected] | Universita' di Pisa
tel: +39-50-568533 | via Diotisalvi 2, 56126 PISA (Italy)
fax: +39-50-568522 | http://www.iet.unipi.it/~luigi/
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