This topic describes the general troubleshooting flowchart and the methods of preliminarily locating faults.
- Locate a fault preliminarily.
Find the fault location and determine the cause of the fault. Table 1 lists the possible causes during preliminary fault locating.
Table 1 Locate a fault preliminarily Fault Type Possible Cause ONT registration failure
- The PON terminal goes online in an incorrect mode.
- The optical fiber connected to the ONT is of poor quality or is loosely connected.
- The optical power of the ONT is not within the normal range.
- The optical module ages or is damaged under abnormal usage.
- The minimum and maximum logical distances configured on the OLT port to which the ONT is connected are inconsistent with the actual distances.
- The ONT auto-find function is disabled on the OLT.
- When the ONT is added, the configured SN of the ONT is different from the actual ONT SN.
- An ONT with the same SN is already connected to the OLT.
- The ONT is a rogue ONT.
Call failure or poor voice quality
- The connection between the telephone set and the ONT is abnormal.
- The ONT port to which the telephone set is connected is configured incorrectly.
- The telephone set does not register with the voice server.
- The voice service of the telephone set is not configured with a high priority.
- The line connections are abnormal.
- The telephone set is faulty.
- The numbers configured on the ONT are incomplete.
- The digitmap configuration is incorrect.
- The codec and authentication configured on the ONT are incorrect.
- A phone number conflict occurs during the registration.
- The voice IP address fails to be obtained.
Internet access failure
- The user terminal or the loop line is faulty.
- The PON port is faulty.
- The data configuration of the upper-layer device is incorrect.
- The PON board on the OLT is faulty.
- The optical path is faulty.
- The board or port on the ONT is faulty.
- There are network attacks.
- The WAN port fails to obtain the address.
- The ping operation with the IP addresses of the ONT WAN port and the ONT fails.
- The WAN MAC address of the ONT defaults to 000000000002.
- The NAT function is disabled on the bound WAN port.
- The LAN port on the ONT is a bridge Ethernet port, but the PC connected to the LAN port fails to obtain the IP address allocated by the upper-layer network.
- Check the status of the optical fiber.Check the following items:
- Whether the optical fiber is properly connected.
- Whether the optical fiber is bent excessively.
- Whether the optical fiber connector is clean.
- Whether the mean launched Tx optical power is normal.
- Whether the Rx optical sensitivity is normal.
- Check the ONT status.Check the status of the LEDs on the ONT.
You can also query the ONT status on the OLT.In the GPON mode, run the display ont info command to check the ONT information. Specifically, mainly check Control Flag, Run State, Config State, and Match State.
- If Control Flag is active and Run State is up, it indicates that the ONT works in the normal state, that is, the user passes the authentication and goes online.
- If Control Flag is active and Run State is down, it indicates that the user is offline.
- If Control Flag is deactive, the ONT registration is disabled. In this case, run the ONT activate command in the GPON mode to activate the control flag.
- If Config State is normal, it indicates that the ONT configuration recovery is successful.
- If Config State is failed, it indicates that the ONT configuration recovery fails. A possible cause of this failure is that the ONT is bound to an incorrect ONT profile. To resolve this problem, run relevant commands to issue a correct ONT profile, or reset the ONT.
- If Match State is match, it indicates that the configured capacity set of the ONT is the same as the actual ONT capabilities. If Match State is mismatch, it indicates that the configured capacity set of the ONT is different from the actual ONT capabilities, which will cause registration failure. In this case, add a new ONT service profile.
- Check the statistics of the ONT.
- In the GIU mode, run the display port statistics command to query the traffic statistics of the upstream port of the ONT. Specifically, check whether receive and transmit traffic exists.
- In the GPON mode, run the display statistics ont command to query the performance statistics of the ONT PON port.
- In the GPON mode, run the display statistics ont-eth command to query the performance statistics of the ONT ETH ports.
- Check the data configuration of the ONT.
- Run the display dba-profile command to check the DBA profile bound to the ONT.
- Run the display service-port command to check whether the traffic stream configuration is correct.
- Run the display vlan command to check whether the upstream port of the ONT is added to a VLAN.
- Check the status of the upper-layer device. Specifically, check whether the OLT is in the normal state.