The number of calls detected on ATM connections associated with this entry, in which the associated endpoint address was identified as the Calling Party in an signalled ATM connection establishment attempt. Note that this value includes calls that are currently in progress. A probe should increment this counter each time a connection attempt is detected in which this ATM host is identified as the Calling Party. Note that for point-to-multipoint ATM connections, this counter is incremented only once per call, regardless of the number of leafs established at setup time or the number of leaf-initiated-join attempts since the call was established.