Store Value: Delta (Speed per second) and sysUpTime

[giotto69]

Hi everybody,
I'm a newbie to zabbix and to this forum, I hope I posted in the correct one.
From my experience with other monitoring tools I see that in order to compute rates (such as average interface speed in bits/sec) the sysUpTime is retrieved from the device together with the interface counter such as ifInOctets.
From a TCP dump on zabbix machine I see that sysUpTime is not retrieved at all.
I guess that the poller time is used: can anyone confirm this?
If this is confirmed I think that this method gives wrong results in case of disomogeneous network delays (jitter > 0).
What do you think?

[ljubica]

You are right

I think you are right, delta (speed per second) is [couter(now)-counter(before)]/update interval, and if host is anavailable or unreachable for some reason and you don't get values for counters for some period you have peaks in graphs. Formula should be [couter(now)-counter(before)]/(now-before).