Chinese
English
Problem description
A, B two sites using OSN 3500 equipment for long-distance transmission, using SL64 + BPA configuration, a day, between the two points of the fiber-optic cable interruption, after line testing, the interruption of the fiber-optic cable by a core, that is, the B received A direction of the fiber optic breaks, but at this time, the network management response, A, B interconnection between the SL64 single-board are reported to the R_LOS alarms, the line will be the core of the fiber-optic cable repair, the two ends of the optical After the line is repaired, the optical alarms at both ends disappear. After the line is restored, turn off the A send B direction laser simulation fiber break a core, found that A, B line board at the same time reported R_LOS alarm.
Alarm InformationR_LOS, OUT_PWR_ABN, IN_PWR_ABN
Processing1, turn off the A send B direction laser, A, B circuit board are reported R_LOS alarm, optical cable fusion error, there will not be two places reported R_LOS alarm, to rule out the possibility of fiber cable fusion error;
2, query the circuit board laser automatic shutdown function, the circuit board does not support the function;
3, analyze the signal flow
A->B direction signal flow for A:SL64->BPA:BA->B:BPA:BA->B:BPA:BA->B:BPA:BA->B:BPA:BA->B:BPA:BA->B:BA:BA->B:BPA:BA > B:BPA:PA->SL64;
The signal flow in the B->A direction is B:SL64->BPA:BA->A:BPA:PA->SL64.
4. Analyze the network management alarms again, and after A turns off the laser, the BA and PA modules of the BPA veneer board at point A report the IN_PWR_ABN alarm, and the PA module of the BPA veneer board at point B reports the IN_PWR_ABN alarm. Point A BPA single board PA module reported IN_PWR_ABN alarm, BA module reported OUT_PWR_ABN alarm. From the alarms, it can be seen that the R_LOS alarm reported on the SL64 board at point A is caused by the BA module at point B sending abnormalities.
5. Why does the BA module at point B report the OUT_PWR_ABN alarm? Checking the characteristics of N2BPA, the difference between N2BPA single board and N1BPA is that N1BPA has two EDFA modules, and N2BPA has only one EDFA module, both of which support automatic laser shutdown and are enabled by default. For N2BPA, there is only one EDFA module, which causes the laser to turn off when there is no optical signal input to either IN1 and IN2 ports. In other words, when the PA module at point B receives no light, it will turn off the laser of the BA module, resulting in the circuit board at point A receiving no light.
2, query the circuit board laser automatic shutdown function, the circuit board does not support the function;
3, analyze the signal flow
A->B direction signal flow for A:SL64->BPA:BA->B:BPA:BA->B:BPA:BA->B:BPA:BA->B:BPA:BA->B:BPA:BA->B:BA:BA->B:BPA:BA > B:BPA:PA->SL64;
The signal flow in the B->A direction is B:SL64->BPA:BA->A:BPA:PA->SL64.
4. Analyze the network management alarms again, and after A turns off the laser, the BA and PA modules of the BPA veneer board at point A report the IN_PWR_ABN alarm, and the PA module of the BPA veneer board at point B reports the IN_PWR_ABN alarm. Point A BPA single board PA module reported IN_PWR_ABN alarm, BA module reported OUT_PWR_ABN alarm. From the alarms, it can be seen that the R_LOS alarm reported on the SL64 board at point A is caused by the BA module at point B sending abnormalities.
5. Why does the BA module at point B report the OUT_PWR_ABN alarm? Checking the characteristics of N2BPA, the difference between N2BPA single board and N1BPA is that N1BPA has two EDFA modules, and N2BPA has only one EDFA module, both of which support automatic laser shutdown and are enabled by default. For N2BPA, there is only one EDFA module, which causes the laser to turn off when there is no optical signal input to either IN1 and IN2 ports. In other words, when the PA module at point B receives no light, it will turn off the laser of the BA module, resulting in the circuit board at point A receiving no light.
Root Cause1. Fiber and cable splicing error;
2. The automatic shutdown function of the circuit board laser is turned on;
2. The automatic shutdown function of the circuit board laser is turned on;
Suggestions and SummaryN2BPA has only 1 EDFA module, when the laser auto shutdown function is turned on, note that when there is no optical signal input from either IN1 and IN2 ports, it will cause the laser to turn off.
Sales OSN3500 SSN2BPA_Product Quotation_Sales Manufacturer_Product Features_Product Description_Huawei SDH Transmission Equipment Sales
OSN3500 SSN2BPA_Troubleshooting_Installation_Tuning_Technical Specification_Technical Parameters_Huawei SDH Transmission Equipment Sales
