This object indicates the reason why the ONT went offline. Options: 1. ontdeleted(0) - The cause of ONT's down is that the ont is deleted 2. linkeddown(1) - The cause of ONT's down is that the ont is disconnected 3. losi(2) - The cause of ONT's down is LOSi(Loss of signal for ONUi) or LOBi (Loss of burst for ONUi) 4. lofi(3) - The cause of ONT's down is that the ont is lofi(OLT can not receive expected optical frame from ONT) 5. sfi(4) - The cause of ONT's down is that the ont is sfi(Signal fail of ONUi) 6. loai(5) - The cause of ONT's down is that the ont is loai(Loss of acknowledge with ONUi) 7. loami(6) - The cause of ONT's down is that the ont is loami(Loss of PLOAM for ONUi) 8. disablefail(7) - The cause of ONT's down is that the ont fails to be deactivated 9. deactivated(8) - The cause of ONT's down is that the ont is deactivated 10. reset(9) - The cause of ONT's down is that the ont is reseted 11. reregister(10) - The cause of ONT's down is that the ont is registered again 12. popupfail(11) - The cause of ONT's down is that the ont popup test fails 13. authfail(12) - The cause of ONT's down is that the ont authentication fails 14. powerdown(13) - The cause of ONT's down is that the ont is powered off 15. reserved(14) - Reserved 16. loki(15) - The cause of ONT's down is that the ont is loki(Loss of key synch with ONUi) 17. ringDeactivated(18) - The cause of ONT's down is that the ont is deactivated due to the ring 18. broadcastAttackDeactivated(34) - The cause of ONT's down is that the ont is deactivated due to broadcast attack 19. operatorCheckFail(35) - The cause of ONT's down is that operator check fail 20. noerror(255) - The cause of ONT's down is that the ont is noerror 21. invalid(-1) - Indicates that the query fails or no information is detected 22. rogueOntselfDetected(37) - The cause of ONT's down is that the rogue ont detected by itself