By | October 29, 2014

Symptom: In the deployment of the project of the OSN1500B Ring we have a problem that happened without any notice in the site with external clock reference,this alarms caused an cut of an BER test performed in the network.

Huawei OSN 1500

Alarm Information: 

Those alarms are cleared without any operation and customer need know why those alarm happened.

In the deployment of the project found the follow alarms in the CXLLN board for one of four SDH equipment.
-HSC_UNAVAIL —-> in the R2CXL sub board.
-BD_STATUS ——> in the R2SLN, R2CXL and GSCC sub boards.
-COMMUN_FAIL –> in the GSCC sub board.

This equipment is connected to OSN 8800 and in this equipment appears an R_LOS Alarm in the same time thet the alarms in the OSN 1500B.

Following the possible cause, we analyze it as below:
Firstly, we check the operation logs.
There is no reset operation during this period.

operation logs So this alarm is not caused by hard reset manually.

Secondly, we check the blackbox information of CXL board;

Thirdly, we confirmed with R&D and know it is known issue, which is a software bug on OSN 1500B with SSR2CXL board:
the clock module detect that the register is error, and set this board fault and hard reset, that is why the CXL board report HSC_UNAVAIL and BD_STATUS alarms.
This issue can happen on the NE version which is V1R10C03SPC203 or earlier.

The occurring rate is very small, but if the clock source is switching very frequently on this NE, the rate will be increasing.

Handling Process:

The solution provided by R&D is upgrade the equipment software version from V100R010C03 to V100R010C03SPC208.

-We apply for the new version in the support page.
-Obtain the Approvals.
-Download the new package.
-Upgrade the new software using the simulation package method.
-Replicate the failure scenario with the clock issue (conmute the clock between CXLLN boards.)

Suggestions and Summary:

The conclusion of the root cause is:

The clock module detect that the register chip is error, and set this board fault, then hard reset, that is why the CXL board reported HSC_UNAVAIL and BD_STATUS alarms.
The suggestion is install or upgrade the software of the OSN1500 equipment to V100R010C03SPC208 or later version.


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