95th Percentile again!

Sun Jun 3 05:14:22 UTC 2001

[ On Sunday, June 3, 2001 at 01:04:00 (-0400), Richard A. Steenbergen wrote: ]
> Subject: Re: 95th Percentile again!
>
> Actually I was refering to the more common methods of rate based
> measurement, MRTG.

Well, MRTG works the way I said, but it also fails to account for
several very critical issues necessary for any auditable accounting
system.  Using it for billing is, how shall I say, not smart!

If I'm not mistaken it's author even warns against this kind of use.

Certainly cricket users are warned regularly not to use it for billing
purposes, and it's even less likely to make an error than MRTG
(particularly recent versions that do NOT use the "derive" method for
counter variables -- "derive" mimics MRTG's errant methods, but is more
"robust" in the face of errant SNMP agents, at least for capacity
planning purposes).

> The names of the providers who use this will be
> omitted. :P

Usually the errors that can happen to MRTG will be in the customer's
favour, but not always.

Any providers using MRTG to calculate rates for billing purposes should
probably call their lawyers on Monday AM and make sure their bases are
covered should any of their customers gain even half a clue.

Any customers who are being billed by an ISP using MRTG should quickly
install their own more accurate and properly designed accounting system
and monitor their end of the pipe to make sure that any errors in MRTGs
measurements remain in their favour.

-- 
							Greg A. Woods

+1 416 218-0098      VE3TCP      <gwoods at acm.org>     <woods at robohack.ca>
Planix, Inc. <woods at planix.com>;   Secrets of the Weird <woods at weird.com>