Common OTN Alarms Highlighted

The most common OTN Alarms :

1. OTUK_LOF: is an OTUk-layer alarm. It indicates that the OTU frame is lost.This alarm is reported if the FAS overhead stays in out of frame (OOF) state for three consecutive milliseconds.The alarm is cleared after the frame synchronization state is restored for three consecutive milliseconds.
2. OTUk_LOM is an OTUk-layer alarm. It indicates that the OTUk multiframe is lost. This alarm is reported if the MFAS overhead stays in out of multiframe (OOM) state for three consecutive milliseconds (ms), that is, the MFAS overhead is invalid. The alarm is cleared after the multiframe synchronization state is restored for three consecutive milliseconds (ms).
3. ODUk_PM_TIM: ODUkPM trace identifier mismatch (TIM) alarm. This alarm occurs during the control process when the trail trace identifier (TTI) at the opposite end mismatches that at the local end while the TIM detection is enabled
4. DEG: signal degraded
5. BEFFEC_EXC:Signal degraded before FEC. Signals sent from the WDM side of the opposite-end OTU have the FEC function. As a result, before performing signal FEC in the receive direction on the WDM side of the local-end OTU, the local-end OTU counts the bit error rate. This alarm is generated when the counted bit error rate crosses the threshold.
6. ODUk_PM_DEG: ODUkPM signal degrade alarm. When BIP8 bit errors are detected in burst mode, this alarm is generated after signal degrade or bit error threshold crossing occurs. When BIP8 bit errors are detected in Poisson mode, this alarm is generated after signal degrade occurs.
7. ODUk_PM_EXC: This alarm is reported when the BIP8 bit errors in the ODUkPM section exceed the specified threshold. When BIP8 bit errors are detected in Poisson mode, this alarm is generated after bit errors exceed the specified threshold.
8. ODUk_PM_BDI: ODUkPM backward defect indication alarm. This alarm is transmitted by the peer site to the local site when the peer site detects a signal failure in the PM section.
9. ODUk_PM_OCI: ODUkPM open connection indication alarm. This alarm is reported when the output port is not connected to the input port and the STAT value is "110".
10. ODUk_PM_AIS: ODUkPM alarm indication signal. An AIS signal is transmitted to the downstream direction, indicating that a signal failure is detected at the upstream direction.
11. ODUk_LOFLOM: abnormal frame and multiframealignment signal alarm. This alarm occurs when the information of the upstream frame header does not match that of the downstream frame header.
12. ODUk_TCMi_TIM: ODUkTCMitrace identifier mismatch alarm. This alarm occurs during the control process when the trail trace identifier (TTI) at the opposite end mismatches that at the local end while the TIM detection is enabled. The system compares the access point identifiers (APIs) in the input signals and the expected APIs.
13. ODUk_TCMi_DEG: ODUkTCMisignal degrade alarm. When bit errors are detected in burst mode, this alarm is generated after signal degrade or bit error threshold-crossing occurs. When bit errors are detected in Poisson mode, this alarm is generated after signal degrade occurs.
    
14. ODUk_TCMi_EXC: This alarm is reported when bit errors in the ODUkTCMisection exceed the specified threshold. When bit errors are detected in Poisson mode and exceed the specified threshold, this alarm is generated.
    
15. ODUk_TCMi_BDI: ODUkTCMibackward defect indication. This alarm is generated when the BDI bit of a TCMioverhead stays "1" for five consecutive frames
16. OPUk_PLM: OPUk payload mismatch alarm. This alarm is generated when the type of received payload mismatches the expected payload type defined in the adaptation function.OPUk_MSIM: OPUk multiplex structure identifier mismatch alarm