The threshold used to determine when to set the tracked
object's etsysTrackedObjectsCommonState to 'down'.
If the value of etsysTrackedObjectsPortGroupUpCount is
less than or equal to this value, the
etsysTrackedObjectsCommonState for this tracked object is set
to 'down'.
This value MUST be less than the value specified in
etsysTrackedObjectsPortGroupUpThresh. An inconsistentValue
error is returned if the value of a set operation is greater
than or equal to etsysTrackedObjectsPortGroupUpThresh.