What does 95th %tile mean?

David Schwartz davids at webmaster.com
Sun Apr 22 00:49:05 UTC 2001



> > 	If Burger King couldn't bill an average of 3% of their
> > customers due to
> > billing error, they'd raise their prices 3%. The net amount
> > paid by their
> > customers would still be the same and their total revenue would
> > still be the
> > same. They'd still be just as competitive. They'd just be billing based
> > upon, you guessed it, statistical sampling.

> Even if I lose 3% of all flows that does not mean that I also lose 3% of
> valuable data. It depends on which flows have been thrown away.
> In the worst
> case you may lose nearly 100%, in the best case you almost lose
> nothing. It
> would be interesting which algorithm is been chosen for throwing
> away flows.

	Logic would dictate that during the heaviest traffic, when the router is
working the hardest, it's more likely to lose flows. But that's just what
you'd expect, not necessarily what actually happens.

> Furthermore: you will never bill byte by byte. That means a
> customer has to
> pay x $ per Gig. If he used 2.1 Gig he has to pay for 3 Gig, if
> he used 2.9 Gig
> he also pays for 3 Gig.

	In other words, a customer that uses 2.99 gig pays less than a customer
that uses 3.00 gigs. So that 3% loss could make a big difference. Yes, it
will make a difference less often, but when it does, it will be a bigger
difference. In fact, I would expect that a 3% loss will, on average, result
in 3% less revenue from overusage.

	Again, the billing is based upon statistical sampling. Really.

	DS





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