Description of the problem

The T_LOSEX alarm is reported on the N1EFT8 Ethernet veneer board of an OSN3500 device at a site, and the alarm is not reported when placed in slots 5 and 13 (currently in slot 5), but is reported when placed in slots 14, 15, and 16 (currently plugged in on slot 14). Parameters 0X01, 00, 01, 02, 08.

Alarm information

T_LOSEX

Processing

1. The T_LOSEX alarm indicates that the single board has detected a backplane service bus signal loss alarm. This alarm is reported if the board detects that the backplane service bus is in LOS state.

2, the board is placed in slot 5 or 13, the alarm disappears, the board is judged normal.

3, placed in slots 14, 15, 16 will report T_LOSEX alarm, multiple slot failure is less likely, check the slot is also normal.

4, according to the T_LOSEX alarm guidance, alarm parameter 3 is 0X01, which indicates a small slot cross-board failure, and is judged to be a 9-slot cross-board SXCS failure.

5. Reset the 9-slot crossover board SXCS, the alarm does not disappear; replace the 9-slot SXCS board, the alarm still exists; pull out the 9-slot, the alarm is still reported. Rule out 9-slot single board failure. Suspect that the corresponding motherboard slot in slot 9 is faulty.

6, check the 9-slot motherboard slot slot, there is indeed the existence of slot edge inverted pin phenomenon, but analyze the inverted pin does not affect the Ethernet single board reported T_LOSEX alarm, and the inverted pin will be broken back to the normal state, the alarm still does not disappear. (Note: the operation of the motherboard pin is a high-risk operation, operation with electricity may burn the motherboard, must be strictly in the case of equipment power down operation, and after the operation can not guarantee that the motherboard pin is normal, it is generally recommended to directly replace the motherboard)

7, replace the motherboard, the alarm is still reported. Rule out motherboard failure. So far, doubt whether other slots single board caused by the bus failure.

8, laboratory analysis, found that the information for the N1EFT8 board reported T_LOSEX alarm parameter analysis description is wrong, (T_LOSEX alarm parameter analysis is valid for other Ethernet board).

At present, all NGSDH equipment N1EFT8 single board T_LOS_EX alarm parameter actual meaning should be:

Parameter name Parameter meaning

Parameter 1, fixed at 0x01, has no meaning.

Parameter 2, Parameter 3 Fixed to 0x00 0x01, meaningless.

Parameter 4 Cross-vendor bus currently selected by the current SSN1EFT8 veneer board

- 0x01 indicates the cross-single board with small ID slot currently selected.

- 0x02 indicates the currently selected cross-single board with large ID slot.

Parameter 5 Each bit represents a good or bad backplane bus.

- A bit[0] of 1 indicates that the 1st bus sent by the cross of ID small slot is bad.

- A bit[1] of 1 indicates that the first bus crossed from the ID large slot is bad.

- A bit[2] of 1 indicates that the 2nd bus crossed from the ID small slot is bad.

- A bit[3] of 1 indicates that the 2nd bus crossed from the ID large slot is bad.

9、According to the conclusion, parameter 4 is 0X02, which means that the cross bus of 10 slots is selected; parameter 5 is 0X08, which is converted to binary 1000, and bit[3] is 1, which means that the 2nd bus sent from the cross of ID big slot is bad.

Judgement for 10-slot cross single board failure

10. After replacing the 10-slot crossover board SXCS on site, the T_LOSEX alarm of N1EFT8 board disappears.

Root cause

1. N1EFT8 board failure.

2、Cross single board failure

3、Mother board failure

Recommendations and summary

1, for the alarm, generally in accordance with the description of the information can be dealt with, but for the need to replace the equipment motherboard operation must be careful, to put forward more doubtful points. For example, the operation of the pre-suspected motherboard failure, but check the motherboard slot is indeed normal, then this time to replace the motherboard is correct, whether there are other reasons for this?

2, follow-up to promote the N1EFT8 single-board code rewrite, so that its T_LOSEX alarm parameters and information description consistent. (N1EFT8 is not developed in strict accordance with the alarm parameters)

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