Skip site navigation (1)Skip section navigation (2)
Date:      Thu, 10 Jul 2003 12:04:09 +0200 (CEST)
From:      Dirk-Willem van Gulik <dirkx@webweaving.org>
To:        Terry Lambert <tlambert2@mindspring.com>
Cc:        Max Clark <max.clark@media.net>
Subject:   Re: What ever happened with this? "eXperimentalbandwidthdelayproduct code"
Message-ID:  <20030710115853.O96627-100000@foem>
In-Reply-To: <3F0D3849.9E3AF6BD@mindspring.com>

next in thread | previous in thread | raw e-mail | index | archive | help


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



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20030710115853.O96627-100000>