The EXT ports on the AUX boards of two sets of the OptiX OSN 3500 are incorrectly connected. As a result, boards fail to be added. To solve this problem, remove the cable that incorrectly connects the EXT ports.
Product

OptiX OSN3500
Fault Type

DCN Fault
BD_STATUS
Symptom

One SEP1 board on the OptiX OSN 3500 reports the BD_STATUS in an interrupted manner. Erase the data on the SCC board, reset the SCC board. It is found that all boards fail to be added. After the boards are added through other methods, the BD_STATUS alarm on the original SEP1 board persists. The board type of the original SEP1 switches between the PQ1 and the SEP1. The board type of the original EU08 board in slot 19 switches between the EU08 and the D12S. In addition, the idle slot 20 is incorrectly shown to house the D12S board.
Cause Analysis

The data configuration on the SCC board may be incorrect or the inter-board communication may be faulty.
Procedure

Erase the database and then reset the SCC board. It is found that no reset record exists and that all boards fail to be added.
Erase the database on the SCC board again. Then, reset the SCC board on site, and add boards again. It is found that the SCC board can be added but the other boards fail to be added.
After all the boards are successfully added, the original SEP1 board still reports the BD_STATUS alarm in an interrupted manner. The board type of the original SEP1 switches between the PQ1 and the SEP1. The board type of the original EU08 board in slot 19 switches between the EU08 and the D12S. In addition, the idle slot 20 is incorrectly shown to house the D12S board.
Exchange the SCC board with the SCC in the corresponding extended subrack (OptiX OSN 3500). Then, repeat Steps 1, 2, and 3, and then find that the problem persists.
Check the cables on site. It is found that a cable is used to connect the EXT ports on the two sets of OptiX OSN 3500. Remove the cable and then find that the problem is solved.
Reference Information

The EXT ports of the main subrack and the extended subrack can be connected only when the UXCSA board is configured to connect to the extended subrack. In this case, the alarms and configuration information of the extended subrack are transmitted to the SCC board in the main subrack through the EXT ports. The extended subrack need not be configured with the SCC board and the XCE board.
When the extended subrack is connected to a non-protection chain, the main subrack and extended subrack are independent of each other. Hence, the EXT ports of the main subrack and the extended subrack need not be connected. If the EXT ports are connected by a cable, collision occurs. As a result, boards fail to be added or cannot be smoothly added. In addition, even the board type switches.