Common Problems and Solutions of ONU

Common Problems and Solutions of ONU

Part I. Common Problems and solutions of ONU

1. Users reflect that the user uses the wirelessly connected terminal to access the Internet slowly and disconnects.

Reason: The use environment of the client wireless WiFi model is complicated, which causes the wireless signal crosstalk to drop.


1) Change the wireless channel on the Web page, avoiding the default channels 1, 6, and 11

2) Find a relatively idle channel to use with the WiFi analyzer

2. Switches and routers can’t be connected to the house service wire.

Reason: The ONU is placed in the low voltage silo. It should be due to the quality of the developer’s house service wire.


Pull a cable from the ONU and split it through the switch

3. The indicator light of the user’s ONU voice interface sometimes flashes repeatedly and cannot be fixed normally. At this time, the user’s fixed line is blocked.

Reason: The power supply load is too large, resulting in an insufficient power supply for the ONU.


Change to a socket with fewer household appliances.

Notes: In the process of inspection and repair, we should not only consider the light attenuation, line and optical network terminal but also details like the power supply.

4. The registration times out and the management system does not show that the  ONU is online.

Reason: The staff was negligent and did not tighten the jumper screw.


Climb up the first-level box to find the jumper and tighten it.

5. The line is blocked and the light attenuation value is high.

Reason: The leather cable is relatively fragile and can’t compare with the tensile strength of other network cables and cables


Try to make the leather cable go through a separate tube and not run the same tube with other lines. Don’t make the leather cable kinked and twisted.

6. LOS lights are red.

Reasons: It may be due to the blocked optical path, the ONU, the leather cable, the connector, the single port of the optical splitter, the main fiber, and the OLT.


First, use the optical power to test the value of the optical loss. If the optical loss is large or there is no light, please check whether the connector and the splitter box connector are clean and whether the pigtail is jumped wrong. If the above is correct, please test whether the main fiber has light. Try changing the splitter port. If it is within the specified range, please try it with another terminal ONU.

7. PON light is off.

Reason: The terminal ONU uplink POS port does not match the POS port configured in the work order, the data of a single work order is lost, the terminal password input problem and the pigtail that is connected before the password is modified.


If it is a new community, please reset the password first. If not, please contact the supervisor to see if the password data of the installed work order is normal. Under that POS port

8. PON lights can only be activated once 

Reasons: terminal ONU, single work order data, OLT data failure


Contact the supervisor to check if there is any problem with the OLT. If there is no problem, tell the supervisor to replace the terminal and ask the supervisor to modify the data. If it still doesn’t work, please notify the business to dismantle the machine and record a new work order.

9. The PON light is on and it suggests that 691 username and password error when connecting the broadband.

Reasons: Password input error, username and password input error, password error, port binding problem, user computer problem.


First, re-enter the username and password. If it doesn’t work, check whether there is any problem with the password input. After checking that it is correct, contact the manager to verify the user name and password, view the dial-up information, and unbind.

10. If the registration of the ONU is less than 30%, it indicates that the registration of OLT is unsuccessful.

Reason: computer room, board


The optical fiber port in the computer room is restarted. If it fails, reset the board (all users under the pon port will be disconnected after the board is reset, please use it with caution)

Part II. What kind of ONU should you choose?

There are many brands of ONU in the market. Different ONUs also provides different services. V-SOL ONU is one of the most cost-effective products with high performance. It provides plenty of series of ONU with multifunction. For example, the CATV GPON ONU V2802RGWT supports CATV service and WiFi connection. Like the triple play ONU is integrated with rich Triple-play function, which can be applied in office, home, hotel, enterprise, campus, etc. In conclusion, the ONU that meets your demands is the best one for you.

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