Description of the problem

Huawei SDH equipmentOSN3500 fan speed regulation program, R3 and previous versions and R6 and later versions are inconsistent, so the results returned by using cfg-get-fanspeed query are not the same, for example:

Host version: 5.21.12.42

:cfg-get-fanspeed

FAN-SPEED

FAN-SPEED XC-HIGHEST-TEMPERATURE

auto(mid) 38

Total records :1

Host version: 5.21.16.13

:cfg-get-fanspeed

FAN-SPEED

FAN-SPEED MINIMUM-DISPERSION

auto(high) 580

Total records :1

So what is the exact speed regulation scheme and how do I interpret the returned results?

Processing

Understand the return result of cfg-get-fanspeed according to the corresponding fan speed scheme.

Root Cause

For NGSDH equipment, versions prior to R6 performed fan speed regulation based on the temperature of the network element, so the cfg-get-fanspeed command returns the results of the fan speed and the temperature monitored by the cross-board.

R6 and later versions perform temperature adjustment based on the temperature difference, which is the difference between the maximum allowable normal operating temperature of the key chip on the single board and the current temperature.

The automatic fan speed regulation scheme considers two change processes, speed regulation to high and speed regulation to low:

Speed up

The main control regularly reads the temperature value and tolerance temperature difference reported by all the single board sensors. As long as any single board detects the temperature and the calculated tolerance temperature difference is less than 40°C (=40 degrees), the fan switches from low speed to medium speed.

The main control regularly reads the temperature values and tolerance temperature difference reported by all single board sensors. As long as any single board detects the temperature and the calculated tolerance temperature difference is less than 30℃ (=30 degrees), the fan switches from medium speed to high speed.

To low speed regulation

In order to prevent repeated changes in fan speed at the point of speed change, set the temperature return difference, the main control regularly reads the temperature value and tolerance temperature difference reported by all the single board sensors, all the single boards detect the temperature, and the calculated tolerance temperature difference is less than 38 ℃ (= 38 degrees), the fan is switched from high-speed to medium-speed, otherwise, maintain the original state.

The main control regularly reads the temperature value and tolerance temperature difference reported by all single board sensors, all single boards detect the temperature, and the calculated tolerance temperature difference is less than 48℃ (=48 degrees), the fan switches from medium speed to low speed, otherwise the status quo is maintained.

In addition, the fan will run at full speed in the following cases:

1. The fan will run at full speed for network elements using old cross-boards:

Huawei OSN3500 SSN1GXCSA, SSN1EXCSA, SSN1UXCSA, SSN1UXCSB

Huawei OSN7500: SST1GXCSA, SST1GXCSB

Huawei OSN2500: SSQ1CXL, SSQ2CXL

Huawei OSN2500REG: SSQ1CRG

2. The main control board is powered on initially, or the main control is not in position, and the fan is running at full speed;

3. In automatic speed control mode, as long as one of the fans is detected offline (BD_STATUS), the other fans run at full speed;

4、Automatic speed control mode, as long as one of the fan failure FAN_FAIL alarm is detected, the other fans run at full speed.

5、Using SSN1FAN and SSN1XDS board with the network element, the fan will run at full speed.

Recommendations and Summary

The fan speed regulation scheme of R6 is too complicated and not reasonable enough, the R&D program is planned to be released in the subsequent version.

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