Does Internet Speed Vary by Season?
Frank A. Coluccio
frank at fttx.org
Sun Oct 11 00:32:36 UTC 2009
I think you are referring, in the case of hierarchical synchronous
architectures (SONET/SDH), to the absolute periodicity of the timing
coming from clock sources. Frame slips and overwrites can occur when
too many ppm lagging or leading are exceeded, as I believe was implied
in your post. In contrast, I believe the notions that are being
discussed in this thread have more to do with the effects of
temperature coefficients of metallic conductors during shifts in
outside temperature conditions, and the ensuing changes in the nominal
velocity of propagation that accompany those changes, relative to the
speed of light.
In any case, I have been following this discussion from its beginning
with a great amount of interest, finding it a great memory jogger from
times misspent in my youth. I started a parallel discussion on my
forum, where today I responded to another poster with the following
observations, for anyone interested.
--- fred at cisco.com wrote:
From: Fred Baker <fred at cisco.com>
To: Dragos Ruiu <dr at kyx.net>
Cc: nanog at nanog.org, Joe Greco <jgreco at ns.sol.net>
Subject: Re: Does Internet Speed Vary by Season?
Date: Sat, 10 Oct 2009 14:27:07 -0700
On Oct 9, 2009, at 5:38 PM, Dragos Ruiu wrote:
> Well, since it's been documented that internet speed / usage varies
> the weather (it gets faster when it's sunny, slower when it rains)
> I'm sure some
> seasonal correlation could be found.
Could you point to the documentation?
I having trouble with language that sounds like one concept and I
suspect is in fact another. Take as one example the basic digital
signaling hierarchy. The specifications call for a certain rate plus
or minus some number of parts per million. If they are within
tolerance, the amount that they would speed up or slow down is
measured in a pretty small number of bits per second. So I don't think
the speed of the links is materially changing. If on the other hand we
are discussing the volume of traffic using that available capacity, it
is absolutely clear that there are diurnal, weekly, and seasonal
variations as well as growth in time.
Are we talking about bit rate, which one might expect to be modified
by environmental characteristics and is in fact very tightly
controlled to prevent that, or traffic volume?
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