Description of the problem

One day, a customer reported that the N1SLD4 in slot 15 of a Huawei SDH OSN3500 device (5.21.18.50) was unable to query the "VC4 channel overhead" in the "Overhead Management" section of the network management, and there was no display in the "Object" column. There is no display in the "Object" column, but the overhead query of other optical boards of this network element is normal.

Process

1. Instruct the customer to query the service configuration, there are 15 slots for N1SLD4, so exclude the cause of service configuration.

2、Customers have replaced this board on their own in the past, and the fault remains, so exclude the reasons for the single board.

3、Asked the customer in detail, he learned that: the 4-slot N1SLD4 of this network element and the 15-slot N1SLD4 grouped 1+1 linear multiplexing segments, in which the 4-slot N1SLD4 is the working channel and the 15-slot N1SLD4 is the protection channel, and it is precisely due to the 15-slot N1SLD4 is the protection channel, which leads to the 15-slot N1SLD4 not being able to query "VC4 channel overhead" in the "overhead management" in the network management. It is because N1SLD4 in slot 15 is a protection channel that N1SLD4 in slot 15 cannot query "VC4 channel overhead" in "overhead management" in the network management.

Root cause

Expenditures could not be traced to the root cause

1. The optical board is not configured for operations.

2. Single board or version defect.

Recommendations and Summary

Huawei OSN3500 SDH transmission equipment linear multiplexing segment 1+1 protection, when the veneer is a protection channel, the overhead bytes are not displayed, and when configuring the overhead bytes of the [working channel], the host computer simultaneously configures the service and overhead configuration to the protection, the purpose of doing this is because the configuration of bytes such as J1 needs to be the same when interfacing with equipment from some manufacturers, and in order to prevent human modification of the overhead configuration of the backup channel (human modification of the overhead bytes of the protection channel will result in inconsistencies between the overheads of the working and protection during the reversal, resulting in service interruption). overhead configuration (artificial modification of the overhead byte of the protection channel will occur when the work of the inversion, the protection of the overhead inconsistent, resulting in business interruption), so the single board for the protection channel, the overhead byte is not displayed.

The relevant technical information in this chapter and the SDH equipment troubleshooting process is collected and organized by Shenzhen Optical Transmission Network Technology Company Limited (www.opticaltrans.com), reproduced and retained! Our company specializes in Huawei SDH optical transmission equipment,SDH transmission equipment sales.