[117972] in North American Network Operators' Group
Re: Does Internet Speed Vary by Season?
daemon@ATHENA.MIT.EDU (Steve Meuse)
Wed Oct 7 13:47:00 2009
Date: Wed, 7 Oct 2009 13:46:15 -0400
From: Steve Meuse <smeuse@mara.org>
To: joel jaeggli <joelja@bogus.com>
In-Reply-To: <4ACCB087.6090002@bogus.com>
Cc: NANOG list <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
joel jaeggli expunged (joelja@bogus.com):
> ADSL systems will retrain to a lower rate as line conditions (SNR)
> change for the worse. The attentuation characteristics of a given pair
> will change of time due to a number of factor, including but not
> certainly limited to physical wear, moisture invasion, localized source
> of interference, sunspot activity etc.
>
> Are dsl plants subject to localized environmental conditions? Absolutely.
I could be convinced that extremem heat could change a cables velocity factor, but that should only result in slight changes in phase, which I guess would result in a higher BER.
Oh, and you forogot about cosmic rays :)
-Steve
