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Re: T3 Latency

  • From: Nipper, Arnold
  • Date: Sat Feb 17 10:54:45 2001
  • >received: from notebook.nipper.de (unknown [192.168.144.1])by gateway.nipper.de (Postfix) with SMTPid AF27D1EE30; Sat, 17 Feb 2001 16:47:29 +0100 (CET)
Chuck,

should read 130mi/msec I guess. Which would end up with ~7msec per
1000miles.


Arnold

----- Original Message -----
From: "Charles Scott" <[email protected]>
To: "Matthew F. Ringel" <[email protected]>
Cc: <[email protected]>
Sent: Saturday, February 17, 2001 3:33 PM
Subject: Re: T3 Latency


>
>
> Matthew:
>   Appears to be a typo in your final number of 130 mi/sec, but I get where
> you're going with this. I'm just having a problem trying to figure out how
> I end up with a couple thousand fiber miles from Northern Michigan to
> Chicago. Should be interesting to sort this one out.
>
> Thanks,
>
> Chuck
>
>
> On Sat, 17 Feb 2001, Matthew F. Ringel wrote:
>
> >
> > The rule of thumb I use is that the speed of light in fiber-optic cable
is
> > roughly 2x10^8 m/sec.
> >
> > 2x10^8 m/sec = 200,000,000 m/sec = 200,000 km/sec = 200 km/msec =~ 130
mi/sec
> >
> > I once worked with a customer whose first hop out was ~30ms, regardless
of the
> > load on the line (a t3, iirc).  Sure enough, he was on a very large
SONET ring
> > that travelled the north-south length of the US roughly twice before his
> > traffic went elsewhere.
> >
> > ......Matthew
>
>
>
>