Hello,
Today I'm going to share with you a solution to the T_LOSEX alarm reported on the N1EFT8 Ethernet board of the OSN3500 device.
Problem Description
A T_LOSEX alarm is reported on the N1EFT8 Ethernet board of the OSN3500 equipment at a certain site. It will not report the alarm when it is placed in slots 5 and 13 (currently in slot 5), and it will be reported in slots 14, 15, and 16 (currently plugged in On slot 14). Parameters 0X01, 00, 01, 02, 08.
Warning message
T_LOSEX
Process
1- The T_LOSEX alarm indicates that the board detects the backplane service bus signal loss alarm. If the single board detects that the backplane service bus is in the LOS state, it will report this alarm.
2- When the board is placed in slot 5 or 13 and the alarm disappears, it is judged that the board is normal.
3- When placed in slots 14, 15, and 16, T_LOSEX alarms will be reported. Multiple slots are less likely to fail. Checking the slots is normal.
4- According to the T_LOSEX warning guide, the alarm parameter 3 is 0X01, which means that the cross-connect board in the small slot is faulty, and it is judged that the SXCS of the cross-connect board in slot 9 is faulty.
5- Reset the SXCS cross-connect board in slot 9 and the alarm does not disappear; replace the SXCS board in slot 9 and the alarm still exists; pull out the slot 9 and the alarm is still reported. Troubleshoot the board in slot 9. It is suspected that slot 9 corresponds to the motherboard slot failure.
6- Check the slot of the motherboard in slot 9 and there is indeed a pin falling on the edge of the slot, but the analysis does not affect the T_LOSEX alarm on the Ethernet board. After the pin is broken back to the normal state, the alarm is still not disappear. (Note: The operation of the motherboard pins is a high-risk operation. Live operation may burn the motherboard. It must be operated strictly when the device is powered off, and the motherboard pins cannot be guaranteed to be normal after operation. It is generally recommended to directly replace the motherboard).
7- If the motherboard is replaced, the alarm is still reported. Troubleshoot the motherboard. So far, it is suspected whether the bus failure is caused by the boards in other slots.
8- We found that the data is wrong for the parameter analysis description of the T_LOSEX alarm reported on the N1EFT8 board (the parameter analysis of the T_LOSEX alarm is valid for other Ethernet boards).
The meaning of the T_LOS_EX alarm parameters of the N1EFT8 board of all NGSDH equipment should be:
Parameter name Parameter meaning
Parameter 1, fixed to 0x01, meaningless.
Parameter 2 and parameter 3 are fixed to 0x00 0x01, meaningless.
Parameter 4 The currently selected cross-board bus of the current SSN1EFT8 board
• 0x01 indicates the cross-connect board of the currently selected ID slot
• 0x02 indicates the currently selected cross-connect board with a large ID slot
Parameter 5 Each bit represents the quality of a backplane bus.
• Bit[0] is 1 means that the first bus sent from the ID slot is broken
• Bit[1] is 1 means that the first bus sent from the ID slot is broken
• Bit[2] is 1 means that the second bus sent from the ID slot is broken
• Bit[3] is 1 means that the second bus sent from the ID slot is broken
9- Parameter 4 is 0X02, which means that the cross bus of 10 slots is selected; parameter 5 is 0X08, converted to binary 1000, bit[3] is 1, which means that the second bus sent from the ID slot is broken.
It is determined that the cross-connect board in slot 10 is faulty.
10- After replacing the SXCS cross-connect board in slot 10 on site, the T_LOSEX alarm on the N1EFT8 board disappears.
Root cause
1- N1EFT8 board failure
2- Cross-connect board failure
3- Motherboard failure
Solution and conclusions
1- For alarms, you can generally handle them according to the description of the data, but you must be cautious about the operations that need to replace the device motherboard, and raise more doubts.
2- Follow-up to promote the rewriting of the N1EFT8 board code to make the T_LOSEX alarm parameters consistent with the data description. (N1EFT8 is not developed strictly in accordance with the alarm parameters).
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