This is a notification-only integer that, for CPE-port alarms, indicates the type of port involved, or for OMCI-managed ONTs specifically holds the Managed Entity (ME) identifier instead. An admin uses this to interpret exactly what kind of CPE port, or for GPON ONTs which managed entity, triggered the alarm, since OMCI-based devices report faults differently from simple port-typed CPEs. For example, on an OMCI ONT, alarmCpePortType might carry the ME id for the Ethernet UNI managed entity that raised the alarm.