Well, since it's been documented that internet speed / usage varies with 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
Hi Fred. 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. [1]http://siliconinvestor.advfn.com/readmsg.aspx?msgid=26010089 Frank --- fred@cisco.com wrote: From: Fred Baker <fred@cisco.com> To: Dragos Ruiu <dr@kyx.net> Cc: nanog@nanog.org, Joe Greco <jgreco@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: 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? References 1. http://siliconinvestor.advfn.com/readmsg.aspx?msgid=26010089