Re: 95th Percentile again (was RE: C&W Peering Problem?)

["Richard A. Steenbergen" <ras () e-gerbil net>]

On Sat, 2 Jun 2001, E.B. Dreger wrote:

> > Date: Sat, 2 Jun 2001 17:28:52 -0400
> > From: Timothy Brown <tcb () ga prestige net>
> >
> > As an interesting aside to this discussion, Digital Island bills for 
> > total traffic transmitted per month (in GB increments).   Does anyone 
> > using them have any comments on this approach besides the obvious?  Does 
> > anyone else do a similar deal?
>
> I only care to mention the obvious... this is essentially the same
> type of billing as average-use total traffic billing.  Total traffic
> in + out, just not divided by number of days in a month. :-)
>
> I can't recall names, but I believe that several colo shops (space +
> bandwidth, not carrier-neutral, a la Exodus) do this.

Of course any system which bills for actual usage is pretty much
statistically fair, regardless of whether its measured in the average of a
rate or total amount sent/received. In my experience, people who bill in
actual GB transfered tend to inflate it substantially to abuse those who
can't do math, but there's nothing wrong with it as a system. I think
people are more used to comparing price in $$$ per Mbit/sec though.

$1 per gigabyte is equivalent to $316/Mbit fairly averaged.

> IMHO, 95th percentile has its drawbacks.  Sure, one can charge more
> for "peaky" customers than with average-use billing, but that can
> backfire in extreme cases:  Recall when the Starr Report was
> released... 5% of a month is 1.5 days, so the heavy traffic during
> that time was simply "above the cutoff".

I'm pretty sure they make out like bandits everytime there is a major
spike like that. Maybe the absolute peak was shorter then 1.5 days, but 2
days later I'm sure there were still people hitting it enough to lock in a
very good peak for that month. Unless the customer is specifically trying
to game the system by bursting only for 4.9% worth and using inbound
traffic to match, they pretty much always win. But I don't think that's
unfair, if 95th percentile is the rules they wanna play by to make money
off the unsuspecting then they should play by it for the plotting as well.
:P

-- 
Richard A Steenbergen <ras () e-gerbil net>       http://www.e-gerbil.net/ras
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