Port: After an Optical Fiber Is Inserted into an Optical Port on the AC, the Optical Port Cannot Go Up

Symptom

After an optical fiber is inserted into an optical port on the device, the LINK indicator of the optical port does not turn on.

Possible Causes

• The optical fiber is faulty.
• The optical module is faulty.
• The in-line optical attenuator cannot meet the requirements.
• A combo port is used but is not working as an optical port.
  • There are four combo ports GE0/0/21, GE0/0/22, GE0/0/23 and GE0/0/24 on the main control board of the AC6605, and the four ports function independently.
  • There are two combo ports GE0/0/7 and GE0/0/8 on the main control board of the AC6003 or AC6005, and the two ports function independently.
  • There are four combo ports XGE0/0/1, XGE0/0/2, XGE0/0/3, and XGE0/0/4 on the main control board of the AC6805, and the four ports function independently.
  • There are four combo ports XGE0/0/1, XGE0/0/2, XGE0/0/3, and XGE0/0/4 on the main control board of the AirEngine 9700-M, and the four ports function independently.
  • For details about the combo optical and electrical ports on more devices, see the interface description of the corresponding device in the WLAN Hardware Installation and Maintenance Guide.

Procedure

1. Replace the optical fiber and optical module and check whether the optical port can go Up.
2. Check the attributes of the optical module as follows:
   • The optical module is a Huawei-certified optical module.
   • The transmission speed of the optical module is the same as the port speed.
   • The wavelength of the optical module is the same as that of the remote optical module.
   • The transmission distance of the optical module is suitable for the actual distance between the two devices.
   • The transmission distance of an optical module can be 10 km, 15 km, 20 km, 40 km, or 80 km. An optical module with a longer transmission distance supports higher transmit power. If an optical module supporting a long transmission distance is used for short-range transmission, the optical interface cannot go Up because the transmit power is excessively high. The high transmit power may even burn the receiver of the optical module. To reduce the transmit power in this situation, use an optical attenuator between the optical module and optical fiber.
   • Optical modules with different speeds are available, for example, 155 Mbit/s, 622 Mbit/s, and 1.25 Gbit/s. It is recommended that you use an optical module with the same speed as the optical interface to ensure efficient optical transmission.

3. If a combo port is used, run the display this command in the interface view to check that the port is configured to work in auto or optical mode.

   <AC> system-view 
   Enter system view, return user view with Ctrl+Z 
   [AC] interface GigabitEthernet 0/0/24 
   [AC-GigabitEthernet0/0/24] display this 
   # 
   interface GigabitEthernet0/0/24 
   combo-port copper 
   # 
   Return 

   If the port works as an electrical port, run the combo-port auto or combo-port fiber command to set the working mode of the port to auto or optical.

   If the port works in auto mode, check whether the combo port is working in electrical mode. If so, remove the Ethernet cable and then install the optical module.

   <AC> system-view 
   Enter system view, return user view with Ctrl+Z 
   [AC] interface GigabitEthernet 0/0/24 
   [AC-GigabitEthernet0/0/24] combo-port fiber

4. Run the display transceiver command to check whether any alarms about the optical module are generated. If so, handle the problem based on alarm information. For example, if an alarm indicating a high RSSI is generated, use an optical attenuator between the remote optical module and the optical fiber.

   <AC> display transceiver interface gigabitethernet 0/0/24 verbose 
   GigabitEthernet0/0/24 transceiver information: 
   ------------------------------------------------------------- 
   Common information: 
     Transceiver Type               :OC3_INTER_REACH_SFP 
     Connector Type                 :LC 
     Wavelength(nm)                 :1310 
     Transfer Distance(m)           :15000(9um) 
     Digital Diagnostic Monitoring  :YES 
     Vendor Name                    :HUAWEI 
     Vendor Part Number             :34060358 
     Ordering Name                  : 
   ------------------------------------------------------------- 
   Manufacture information: 
     Manu. Serial Number            :EH1048220807 
     Manufacturing Date             :2010-12-06 
     Vendor Name                    :HUAWEI 
   ------------------------------------------------------------- 
   Alarm information: 
     RX loss of signal 
     RX power low 
   ------------------------------------------------------------- 
   Diagnostic information: 
     Temperature(°C)              :26.00 
     Temp High Threshold(°C)      :85.00 
     Temp Low  Threshold(°C)      :-40.00 
     Voltage(V)                    :3.29 
     Volt High Threshold(V)        :3.64 
     Volt Low  Threshold(V)        :2.95 
     Bias Current(mA)              :4.57 
     Bias High Threshold(mA)       :9.00 
     Bias Low  Threshold(mA)       :2.00 
     RX Power(dBM)                 :-40.00 
     RX Power High Threshold(dBM)  :0.00 
     RX Power Low  Threshold(dBM)  :-16.99 
     TX Power(dBM)                 :-5.03 
     TX Power High Threshold(dBM)  :-2.22 
     TX Power Low  Threshold(dBM)  :-6.99 
   ------------------------------------------------------------- 

   The attenuation coefficients of single-mode fibers with 1310 nm and 1550 nm wavelengths are 0.4 dB/km and 0.25 dB/km, respectively.

5. If the fault persists, contact technical support personnel.