[9897] in North American Network Operators' Group
A question of stats..
daemon@ATHENA.MIT.EDU (Brian Horvitz)
Sun Jun 8 09:25:52 1997
Date: Sun, 8 Jun 1997 09:07:43 -0400 (EDT)
From: Brian Horvitz <horvitz@websecure.net>
To: nanog@merit.edu
Here is something which has been troubling my mind lately.
The basic question is, how do I turn an in and an out into
an aggregate? Here is a scenario: I measure usage on a
customer's T1 at my router port. Every 5 minutes a sample
the port and figure the average bps both in and out for the
last five minutes. Now, I want to make a number that
represents the aggregate usage across that port but, I cannot
simply add the two ins and outs (as I am doing now) because
they were both averages over a period of time. Doing this
produces some strange effects which can show nice trends but
also lies about the real usage. Perhaps I simply lack the
math experience to do this correctly but I can't see a good
way to do it.
Brian Horvitz
WebSecure, Inc.
