ZyXEL Communications OLT2406, User Manual

Page: 726 / 766

OLT2406 User’s Guide
726
C
HAPTER
109
Troubleshooting
This section describes how to troubleshoot problems occurring on this OLT, the ONTs/ONUs, the ODN, or
the other devices involved in the GPON network.
General checking on the OLT.
Check if all the LEDs on the MSC cards, fan module, uplink cards, and GPON cards are behaving
normally.
Use the
show lc stats
command to make sure each installed card is active. You may need to reinstall
the card or re-configure the slot if it is not.
Check if ONTs/ONUs are up. Contact your local vendor to make sure the ONT/ONU models are
supported.
Check the receiving and transmitting optical power on both the OLT and ONT/ONU devices. They
should be in the normal range. See
The OLT cannot detect an ONU or an ONU cannot connect to the
OLT. on page 726 for the range.
Make sure the fiber cable length between the OLT and each ONT/ONU is not too long (< 20 km).
Check if there is a rogue ONT/ONU. See Section 109.1 on page 728 .
Check if the connected ONTs/ONUs status is stable.
Check for any alarms related to an ONT/ONU by using the
show logging
command.
Check if the settings on the GPON port and the ONTs/ONUs are properly configured. See the Initial Setup
and Provisioning chapters.
The OLT cannot detect an ONU or an ONU cannot connect to the OLT.
Check if the settings and the connection status for the ONT/ONU are correct on the OLT.
Check if any historic alarm occurred related to the ONT/ONU on the OLT.
Check if the transmitting optical power of the GPON port on the OLT is in the normal range (+7~+2 dbm).
You may need to change the PON port optical module if it is too low or too high.
Check if the receiving optical power on the ONT/ONU is in the normal range (-8~-24 dbm) by using the
show interface olt pon-< slot >-< port > ddmi
command. A low value may be caused by high
signal attenuation and you need to check the optical line. A high value might be caused by the OLT