This object carries an ENTITY-MIB entPhysicalIndex value and is included as a variable binding in the h3cPexPhyPortForwarding and h3cPexPhyPortBlocked notification traps to identify which physical port changed state. It lets a trap receiver correlate a PEX port-extender state-change alert with the specific physical entity in the device's inventory without a separate lookup. For example, a management system receiving an h3cPexPhyPortBlocked trap uses this object's value alongside entPhysicalDescr to report exactly which uplink port has become blocked.