The H801GPBC and H802GPBD boards of the MA5600T incorrectly report a rouge ONT
on the optical path and deactivate a normal ONT, which leads to service interruption.
Product Line: Access network Product Model: MA5600T
Fault Description
Trigger conditions:
The MA5600T is of V800R006C02SPC117 or earlier versions, and the rogue ONT detection
and deactivation functions are enabled.
Symptom:
A rogue ONT alarm is generated even if the GPON port of the MA5600T is not connected to
an ONT. If the faulty port is connected to an ONT, the ONT may be deactivated. As a result,
the normal ONT is offline.
Identification method:
1. Disconnect the backbone fiber to ensure that there is no upstream optical signal. However,
a rogue ONT alarm is still generated.
2. Delete the flag of the ONT that is determined as a rogue ONT. Then, if the ONT can go online
without affecting other normal ONTs, the MA5600T incorrectly reports a rogue ONT.
Root Cause
The software for detecting a rogue ONT is too strict. That is, the software does not eliminate jitter
of the SD signal noise reported by the optical transceiver. Furthermore, it deactivates the ONT at
once when it considers the ONT is a rogue one.
Impact and Risk
The normal ONT is deactivated and the ongoing services are interrupted.
Measures and Solutions
Recovery measures:
1. Disable the rogue ONT detection and deactivation functions of the OLT.
MA5600T(config)#anti-rogueont autodetect off
3. Run the undo anti-rogueont command on the serial port of the ONT that is deactivated to delete the rogue ONT flag.
Then, reboot the system.
MA5616(diagnose)%%undo anti-rogueont
{ isolate<K> }:isolate
Command:
undo anti-rogueont isolate --------Deletes the rogue ONT flag.
MA5616(diagnose)%%reboot system
Please check whether data has saved, the unsaved data will lose if reboot
system, are you sure to reboot system? (y/n)[n]:y
Workarounds:
1. For MA5600T V8R6SPC118, improve the version so that a rogue ONT alarm is reported and the
ONT is isolated only after the ONT is detected and determined as the rogue ONT for five consecutive
times.
By default, the rogue ONT detection is disabled.
4. For MA5600T V8R6SPC117, run the following command to disable rogue ONT detection.
MA5600T(config)#anti-rogueont autodetect off
Preventive measures:
Modify the rogue ONT determination procedure to increase stages for collecting error bits and
ONT IDs.
This issue will be resolved in MA5600T V800R006SPC122 on Dec. 2010.
Rectification Scope and Time Requirements
N/A
Notice Expiration
This notice automatically expires in versions later than MA5600T V8R6SPC117.
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