I've seen both "in or out" and "in + out" used by multiple providers within the community. So either approach could be called "industry standard method". As Lee notes, one ought to define the precise algorithm as part of the contract, to avoid just this sort of ambiguity. Ran At 10:18 19/04/01, Lee Watterworth wrote:

...definately one of those things that need to be asked about during contract negotiations...

-----Original Message----- From: Alex Rubenstein [mailto:alex@corp.nac.net] Sent: April 19, 2001 10:09 AM To: 'nanog@merit.edu' Subject: What does 95th %tile mean?

I've gotten myself into an argument with a provider about the definition of 'industry-standard 95th percentile method.'

To me, this means the following:

a) take the number of bytes xfered over a 5 minute period, and determine rate for both the inbound and outbound. Store this in your favorite data-store.

b) at billing time, presumably on the first of the month or some other monthly increment, take all the samples, sort them from greatest to least, hacking off the top 5% of samples. Actually, this is done twice, once for inbound, once for outbound. Then, take the higher of those two, and multiply it by your favorite $ multiple (ie, $500 per megabit per second, or $1 per kilobit per second, etc).

I think that most people agree with the above; the issue we are running into is one rogue provider who is billing this at in + out, not the greater of in or out.

How is everyone else doing it? Specifically, larger folks (UU, Sprint, CW, Exodus/FGC, GX, Qwest, L3)

Thanks!