[mrtg] Definition of peak inbound & outbound traffic?

Steve Shipway s.shipway at auckland.ac.nz
Fri Oct 26 00:06:04 CEST 2007

> Spent considerable time searching, but came up empty.  What is the
> definition of "Peak inbound traffic" and "Peak outbound traffic" on my
> weekly, monthly and yearly graphs? (and how does this differ from the
> regular "Inbound traffic" and "Outbound traffic" graphs?

I'm assuming you have the default 5-min sample interval.

The daily graph is a 5-min granularity, the weekly is a 30-min
granularity, the monthly is a 2-h granularity, and the yearly is a 1-day
granularity.

The daily graph will show you a line corresponding to the 5-min average
(because you are polling every 5 minutes).

The 'Peak' line on the Weekly graph will show the highest 5-min average
for the 30-min period.  The normal line will show the Mean Average over
the 30-min period (IE, the average of the six 5-min averages)

The 'Peak' line on the Monthly graph will show the highest 5-min average
for the 2-h period.  The normal line will show the Mean Average over the
2-h period.

And so on.  From this you can deduce why a 95th percentile calculation
is doomed to fail at higher granularities, and will always be inaccurate
to some degree (if you've studied statistics)

Steve