Possible Cause
Judgment Criterion
Troubleshooting Method
The multi-mode optical
fiber is used as the
backbone or branch
optical fiber.
NOTE
If the multi-mode optical
fiber is used as the
backbone or branch optical
fiber, the optical signal
attenuates quickly and the
return loss increases.
1. Check the backbone fiber
and branch fiber by using
the OTDR. It is found that
optical signals attenuate
seriously.
2. Check the optical path on
site. It is found that the
multi-mode optical fiber is
used. The multi-mode
optical fiber can be
recognized by its physical
features such as its color.
Replace the multi-mode optical
fiber with the single-mode
optical fiber.
The optical attenuation
of the optical path is
excessively small.
NOTE
l
If the optical
attenuation of the
optical path is
excessively small, the
optical power received
by the ONU will
exceed the overload
optical power of the
ONU.
l
Such a situation occurs
usually in labs, where
the OLT and ONU
may be directly
connected to each
other through a short
optical fiber.
If either of the following two
situations occurs, the optical
attenuation of the optical path
is excessively small.
l
Measure the receive optical
power of the ONU by using
the optical power meter. It
is found that the actual
receive optical power of the
ONU is greater than -8
dBm.
l
Check the optical path
between the OLT and ONU.
It is found that the optical
attenuation of the optical
path is excessively small.
The normal attenuation
range is 10-25 dB.
Add an optical attenuator on the
optical path between the OLT
and ONU.
SmartAX MA5612 Multi-service Access Module
Maintenance Guide
6 System Fault Handling
Issue 01 (2012-07-25)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
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