What does 95th %tile mean?

Lee Watterworth lwatterworth at rim.net
Thu Apr 19 14:18:45 UTC 2001



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

-----Original Message-----
From: Alex Rubenstein [mailto:alex at corp.nac.net]
Sent: April 19, 2001 10:09 AM
To: 'nanog at 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!




More information about the NANOG mailing list