[14977] in North American Network Operators' Group
Re: backbone routers' priority settings for ICMP & UDP
daemon@ATHENA.MIT.EDU (John Hawkinson)
Wed Feb 4 15:04:58 1998
From: John Hawkinson <jhawk@bbnplanet.com>
To: mkayser@mci.net (Mark Kayser)
Date: Wed, 4 Feb 1998 14:32:18 -0500 (EST)
Cc: nanog@merit.edu
In-Reply-To: <199802032009.PAA03585@carbon.cary.mci.net> from "Mark Kayser" at Feb 3, 98 03:05:13 pm
> This is not typically a policy that is carried out by the providers. It is
> just how some router vendors have developed their implementations. They
> don't give a lower priority to UDP or ICMP unless that traffic is destine
> for the router itself.
I think that this is insufficiently clear, though correct :-)
Non-optioned traffic *through* a cisco router running IOS
is always treated the same.
Traffic destined *to* one of the addresses on a router
is usually switched with a different switching mode (i.e.
"process switching"). Process switching is a seperate set
of queues on the router, and therefore a seperate set of delays.
Despite various assertions you might hear people make, process switching
is not likely to drop packets more frequently. It is likely to introduce
higher delay.
--jhawk
