The tmnxNatLsnSubBlksFree notification is sent when all port blocks allocated to a Large Scale NAT (LSN) subscriber are released. The NAT subscriber is identified with its subscriber ID tmnxNatNotifyLsnSubId. To further facilitate the identification of the NAT subscriber, its type tmnxNatNotifySubscriberType, inside IP address tmnxNatNotifyInsideAddr and inside virtual router instance tmnxNatNotifyInsideVRtrID are provided. The values of tmnxNatNotifyMdaChassisIndex, tmnxNatNotifyMdaCardSlotNum and tmnxNatNotifyMdaSlotNum identify the ISA MDA where the blocks were processed. All notifications of this type are sequentially numbered with the tmnxNatNotifyPlSeqNum. The value of tmnxNatNotifyNumber is the numerical identifier of the NAT policy used for this allocation; it can be used for correlation with the tmnxNatPlBlockAllocationLsn notification; the value zero means that this notification can be correlated with all the tmnxNatPlBlockAllocationLsn notifications of the subscriber.