T3 Latency

Sat Feb 17 15:47:28 UTC 2001

Chuck,

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

Arnold

----- Original Message -----
From: "Charles Scott" <cscott at gaslightmedia.com>
To: "Matthew F. Ringel" <ringel at akamai.com>
Cc: <nanog at merit.edu>
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
>
>
>
>