Is this a graph of "does this node ping" or is it something more specific?
I'm assuming you mean the resource that produces a series of bars showing availability of your networks for a given time period?
It doesn't poll anything itself, it uses the values already in the database for availability. Usually these values are generated off of ICMP pings, but you can change this to SNMP in "List Resources" for a node.
I'm guessing all its doing is an average on all the Availability values for a given node for the given time period(s).
Pretty basic either way!
