Troubleshooting
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61287802F1-34B
Revision B
7 Troubleshooting
Two principles should be kept in mind when troubleshooting an GPON 452/454 unit:
1. Because voice and data signals both originate at the OLT equipment, a failure of all
services normally indicates the problem is before the GPON 452/454. A failure at the OLT
equipment normally results in a loss of service to multiple customers.
2. The OLT has diagnostic testing procedures that can monitor the status of every GPON
452/454 in the system, which very often can indicate the root cause of the trouble.
Possible activation sequences for the ONT are as follows:
■ Manual Activation - The installer and Central Office personnel communicate to provision
the ONT.
■ Auto-Discovery - Every 20-seconds, the OLT searches for new ONTs in the network.
When a new ONT is discovered, the serial number is uploaded to the OLT and compared
against a list of “expected” serial numbers. If the serial number matches, the ONT is
automatically added to the network.
■ Auto-Activation - This is similar to the Auto-Discovery mode in that the OLT scans the
network every 20-seconds looking for new ONTs. However, when the OLT discovers a
new ONT, it assigns an ONT-ID, uploads the serial number, compares it against the list of
expected numbers, and only when there is a match does the ONT become active.
■ Registration-ID Activation - During this activation process, the installer assigns a unique
10-digit Registration ID number to the ONT and communicates that number to the Central
Office. When the OLT begins its Auto-Discovery process, this number is used in lieu of the
serial number for activation purposes.
During these sequences, it is normal for the LEDs on the front of the GPON 452/454 to cycle.
However, if this cycle takes more than 2 - 3 minutes, a possible problem exists. Refer to
“Network Status Troubleshooting”
on page 46 for possible resolutions.
If the home telephone wires are connected to the Two-screw Terminal Bridge, then the RJ-11
jack serves as a test access point. In this configuration, inserting a telephone cable into the
RJ-11 jack will disconnect the GPON 452/454 from home wiring and connect the GPON 452/
454 to the inserted cable instead. This allows the home owner or service provider to diagnose
GPON 452/454 or home wiring related problems. Inserting an RJ-11 jack (such as a telephone
cable or telephone test set) into the connector, will connect the telephone set to the Single
Family Unit (SFU) and also disconnect the subscriber service from the SFU. Hence fault may
be isolated to the SFU or premises wiring.
This section describes how to troubleshoot and correct the following:
■
“LEDs Normal but Problems Still Exist”
■
■
“ODN Interface Troubleshooting”
■
