[12328] in North American Network Operators' Group
Re: ATM (was Re: too many routes)
daemon@ATHENA.MIT.EDU (Robert E. Seastrom)
Fri Sep 12 11:13:36 1997
Date: Fri, 12 Sep 1997 11:04:41 -0400 (EDT)
From: "Robert E. Seastrom" <rs@bifrost.seastrom.com>
To: nathan@netrail.net
CC: nanog@merit.edu
In-reply-to: <Pine.BSF.3.95q.970912091624.13639B-100000@netrail.net> (message
from Nathan Stratton on Fri, 12 Sep 1997 09:19:39 +0000 (GMT))
From: Nathan Stratton <nathan@netrail.net>
Yep, but you also need to add a few ms for electronics in that 4000 mile
line. We tend to see around 64 - 65 ms delay between our DCA and PAL
routers.
The delays in the electronics in the repeaters (no DACSes in a big ISP
pipe) and muxes along the way don't add up to more than a few tens of
microseconds. Disappears in the noise compared to other factors on
the line. In fact, I daresay the jitter in interrupt service time on
the host on the other end (even on a unix box, let alone a cisco
serving icmp replies in its copious spare time) exceeds the electronic
delays by an order of magnitude or more. Then there's the delay in
getting your packets onto and off of the CSMA/CD network that you
indubitably have at the far end....
---rob
