Trigger conditions of the CHAN_LOS alarm on OTN equipment


The possible causes are as follows:
1. A monitored wavelength is not received actually.
2. The laser on the related board at the peer-end site is off.
3. Optical power variations of the monitored wavelengths are too large.
4. The multiplexing or amplifier unit connected to the MCA board has an overly large attenuation value.
5. The OTU board in the upstream direction of the MCA board is faulty.
6. The MCA board that reports the alarm is faulty.

Other related questions:
Conditions for the MCA board of the BWS 1600G to determine a wavelength loss and report the CHAN_LOS alarm
Question: What is the condition for the MCA board to report the CHAN_LOS alarm when wavelength monitoring configurations are correct? CHAN_LOS Answer: The MCA board determines a wavelength loss when it detects the following wavelength conditions: 1. The optical power is lower than -40 dBm. 2. The optical power is greater than 5 dBm. 3. A wavelength exceeds the standard wavelength by ±0.14 nm. 4. The signal-to-noise ratio is smaller than 7.5 dB. 5. If the difference between the maximum and minimum optical power is greater than 10 dB, the MCA board determines that the wavelength with the minimum optical power is lost.

Products included in OTN equipment
Currently, Huawei OTN devices include OSN 1800, OSN 3800, OSN 6800, OSN 8800, and OSN 9800.

Supported protection schemes at the OTN layer of Huawei OTN equipment
The following protection schemes are supported at the OTN layer of Huawei OTN equipment: client 1+1 protection, intra-board 1+1 protection, OLP, ODUk SNCP, tributary SNCP, and ODUK SPRing.

Difference between conventional WDM equipment and OTN equipment
Both of them use the DWDM technology. The difference between them lies in that OTN equipment can achieve electrical cross-connection scheduling for various types of services.

Precautions for setting rerouting trigger conditions on an ASON network
Rerouting trigger conditions are determined based on the number of available network resources and service importance. If there are sufficient resources or protected services are important, you can select the policy of triggering rerouting when any LSP fails. In this way, 1+1 protection is retained for services under SNCP protection or optical-layer associated services, and quick switching can be achieved upon a fault. Even if a rerouting failure occurs, the failure can be detected in a timely manner. If there are insufficient resources or the protected services are less important, you can select the policy of rerouting when both LSPs fail. In this way, the 1+1 protection provided for the services can survive only one fault. When both LSPs fail and service rerouting is triggered, the service will be interrupted for a short time (depending on the rerouting time), or be interrupted for a long time if rerouting fails.

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