T3 Latency
Matthew F. Ringel
ringel at akamai.com
Sat Feb 17 15:16:41 UTC 2001
Yup. Dropped a letter there. 130mi/msec.
.....Matthew
On Sat, Feb 17, 2001 at 09:33:02AM -0500, Charles Scott wrote:
>
> 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
More information about the NANOG
mailing list