What ever happened with this? "eXperimentalbandwidthdelayproduct code"

Dirk-Willem van Gulik dirkx at webweaving.org
Thu Jul 10 03:04:35 PDT 2003



On Thu, 10 Jul 2003, Terry Lambert wrote:

> > Okay, let's say how do I force my machine to think it doesn't have any
> > latency and saturate a 6Mbit/s link even though the link has 220ms latency?
>
> See the recent discussion on the FreeBSD-performance mailing list.

Your propblem is similar to that encountered in sat links; where you have
at least a 2 x 280ms RTT's and exteremely reliable/error free 'big' links
(ok, that is not quite true; but the ECC is configurable so you simply set
the error rate; and use power, width and dish size amongst other as a
design parameter to play iwth).

Another goed overview document is best current practices for satellite
links (BCP28):

	http://www.faqs.org/rfcs/rfc2488.html
or
	http://mmlab.snu.ac.kr/course/AdvancedInternet/reading/SatelliteTCP.htm

Alternatively if a specific protocol is involved the use of a proxy for
that protocol to intentionally break end to end semantics can do wonders.
We've done this in the past for protocols such as ftp, http and smtp; and
it works wonders.

Dw



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