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Downtime Reporting Basics



I am wondering how downtime is calculated from a sensor. I see the reporting as a Percentage of the time interval which the device was down. Does the sensor ping the device at an interval until it finds the device to be down, at which point it pings every second to get an accurate downtime? Or does the sensor continue to ping at an interval to get an approximate downtime?

downtime interval prtg

Created on Jul 16, 2012 7:21:06 PM

3 Replies




in case of a "down" a sensor does not change its scanning interval. To be able to make an exact and definitely correct statement about downtime, PRTG then only accounts the time between at least two consecutive down-scans (or 10 or 50, etc., consecutive down-scans) as downtime.

best regards.

Created on Jul 17, 2012 11:28:45 AM by  Torsten Lindner [Paessler Support]



Thank you for your quick response. As a follow up, I'm having trouble figuring out how the software if calculating downtime. Are the down-scans on the same interval as the ping intervals?

For example, the ping interval is 30s, but in a 1minute period I'm reading downtimes of 66%. How can the software break down the downtime into seconds if the intervals are in half minutes?

Created on Jul 17, 2012 1:32:17 PM



The scanning interval is not changed whether a sensor is up or down. It's always the same scanning interval.

Created on Jul 17, 2012 2:52:30 PM by  Torsten Lindner [Paessler Support]

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