Description of the problem

Due to the optical road instability customers want to the existing 16 nodes on the 2500 + STM-16 MSP ring will be one section of the link cut to the OSN3500 equipment, that is, in the OSN3500 equipment to configure the business work and protection channels totaling 16 VC4 level of pass-through and K bytes of the pass-through to achieve the protection of the MSP ring, the fiber breakage test MSP ring inversion failed, but customer feedback This scenario has been successfully applied on friendly equipment.

Alarm Information

K-byte pass-through setup with command line cm-add-dccphy, but MSP ring inversion failed.

Processing

1, the new link OSN3500 6-SL16 and 5-SL64 single board for cross-passing and K byte pass-through, which 5-SL64 single board is already in the STM-64 MSP ring, so the use of D byte for K byte pass-through transfer, the command line is as follows: :cm-add-dccphy:6,1,K1,5,1,D11;cm-add-dccphy:6,1,K2,5,1,D12, command line issued successfully and use :cm-get-dccphy:6,1,K2,5,1,D12, command line issued and use :cm-get-dccphy:6,1,K2,5,1,D12 add-dccphy:6,1,K2,5,1,D12, the command line is issued successfully and :cm-get-dccphy is used to check that the configuration is correct.

2, replace the relevant circuit board, main control board, device type and software version of the problem remains.

3, in the headquarters of the laboratory to simulate the same phenomenon.

4, consult the relevant documents to learn the line single board to receive K bytes, will not choose from the main control board to select the source, only to receive a single board side of the selected source or the pair of board bits of overhead. The use of K bytes through the transmission link in the event of fiber breaks or other alarms can not be triggered by the inversion, resulting in MSP protection is not meaningful; at the same time, K bytes through the master control will be filled with K bytes to the other bytes of the overhead, after the transmission link, restore back to the K bytes. The whole process is intervened by the master control twice, the speed of K byte transmission is obviously reduced, and the inversion time cannot be guaranteed within 50ms.

5. Therefore, in using the command line cm-add-dccphy, although it is issued successfully but actually K bytes cannot be transmitted to the opposite end.

Root cause

1. Single board failure, master control failure, device version, device model problem.

2. Wrong Kbyte passthrough setting.

3、Device software is not supported.

4. Equipment specification limitations.

Recommendations and summary

OSN equipment (including OSN9500 NG_SDH) product specification limitations can not be set with the command line K-byte passthrough, it is recommended that scenarios that require the use of K-byte passthrough use shared multiplexing segments or SNCP instead.

The related technical information and SDH equipment troubleshooting procedures in this chapter are collected and organized by Shenzhen Optical Transmission Network Technology Company Limited (www.opticaltrans.com), please retain the reproduction! Our company specializes in the sale of Huawei SDH optical transmission equipment,SDH transmission equipment.