last and the new time_shift parameter

[fjrial]

Hi:

As you know, in zabbix 1.8.2, "last" function has a new parameter:
"Parameter time_shift is supported starting from Zabbix 1.8.2."

and I want to know how if it's supposed to work and which values would return last function.

If last has no time-shift parameter, it'll always return a value: the last one.
But, if you indicate the time-shift parameter, and if in that time, there is no data for the item, what will be the value that "last" will return?? the last one (no matters if is out of the time-shift) or zero or none??

This is vital for my installation, because an unwanted zero in our monitors could decrease the avg bandwith usage.

Thanks for your help.

[fjrial]

the last one

I did some testing and it seems that it always return the last value, no mather if the item has no value during the last "time shift parameter" seconds.

I think that an item with such a function to calculate a value, should have "no data" or null value if no value present during the time_shift parameter.

Any idea or an approach to do this??

Cheers.