Description of the problem

OSN3500 single station does not report TU_AIS alarm after configuring 1 tributary 2-slot E1 service.

Processing

First of all, OSN3500 host version is 5.21.33.72, to verify that the business is active and discrete, the circuit board optical port is also a collection of light-emitting power.

Therefore, there is no line board if there is a RLOS alarm, will inhibit the branch board to report the case of TU_AIS. Since the service is only a single-station configuration, there must be TU_AIS reporting.

1-1, using U2000 network management to check the network element alarm is automatically reported, and does not inhibit

1-2, check the U2000: fault - settings - shielding rules, found that there is no shielding events of this 3500 network elements.

Second, the side of the network management did not check the anomaly, consider the next step in the positioning of the network element level

2-1, use the command line to query the current alarm of the network element, and no record of TU_AIS is found.

2-2, use: alm-get-monevent:10,0,0,0,0,0, query the alarm monitoring status and found that all are enabled.

As there is inter-board suppression on OSN devices, we will focus on the following

Inter-board alarm suppression refers to the same network element when there is a service configuration between the two boards, the source board generated service alarms will suppress the host board generated service alarms. The device supports alarm suppression between line boards and tributary boards or between line boards and data boards. The purpose is to focus on the root cause alarms generated by the service source.

3-1. query the command-line manual. use the command:alm-get-inhistate to query the alarm events that are suppressed for a network element. reporting an error is not supported. Use the command line: inh association, find the structure of similar: alm-get-inhdata-ext, query really found that there is TU_AIS alarm event.

3-2, use the prohibit inter-board alarm suppression command: alm-set-inhistate:inhibit, continue to report errors, use inhistate, did not associate the desired command.

3-3, query information, in the R11 command line manual found a host 5.21.33.72 similar command: alm-cfg-set-inhistate:disable, login to the network element to run, the command is issued successfully, TU_AIS alarms reported normally.

Root Cause

The inter-board alarm suppression relationship can be seen in the figure below. In this problem, the inter-board alarm suppression is enabled due to the presence of MS_AIS alarms on the 7-slot line board, which results in the suppression of TU_AIS alarms on the tributary boards.

The specific inter-board alarm suppression relationship is as follows:

Recommendations and Summary

Network elements do not report TU_AIS problems, basically can follow this line of investigation, the problem can basically be solved.

This chapter of related technical information and SDH equipment troubleshooting process by Shenzhen Optical Transmission Network Technology Co. Huawei SDH optical transmission equipment, SDH transmission equipment sales