Huawei EchoLife HG861 Manual page 54

5 Troubleshooting
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The method of ranging in the GPON system is to perform delay compensation for all ONTs
connected to one PON port so that the ONTs are logically at the same location as the ONT
that is in the furthest distance from the OLT.
Q: How does the GPON system bear the triple play service?
A: The GPON system bears the triple play service in the following modes:
Single GEM port for multiple services
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Multiple GEM ports for multiple services
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One TCONT is bound to one GEM port in the upstream direction
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One TCONT is bound to multiple GEM ports in the upstream direction
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Q: What are differences between the five types of T-CONTs in the GPON system?
A: In the case of T-CONT 1, the bandwidth is allocated statistically. The assured bandwidth
is the maximum configured bandwidth and the bandwidth of T-CONT 1 is allocated with
a priority.
In the case of T-CONT 2, only the assured bandwidth of users is guaranteed. If the assured
bandwidth exceeds the maximum bandwidth, the maximum bandwidth is allocated.
In the case of T-CONT 3, the assured and non-assured bandwidths are allocated. If the
requested bandwidth can be ensured, the bandwidth is allocated directly upon request.
Otherwise, the left bandwidth that cannot be allocated is labeled and allocated with the
bandwidth labeled with tags of T-CONT 5 based on the round robin (RR) algorithm.
In the case of T-CONT 4, the non-assured bandwidth is allocated. After the assured
bandwidth is allocated, the left bandwidth and the left bandwidth of T-CONT 5 in the
requested bandwidth are allocated based on the RR algorithm.
In the case of T-CONT 5, hybrid bandwidth is allocated. Check whether the assured
bandwidth meets the requirement. If the assured bandwidth meets the requirement, the
bandwidth is allocated directly. If the assured bandwidth does not meet the requirement,
the left bandwidth is labeled and allocated with the bandwidth labeled with tags of T-CONT
3 based on the RR algorithm. If the bandwidth cannot meet the requirement yet after
allocation, T-CONT 5 competes with T-CONT 4 for the left bandwidth.
Q: What are the specifications of the GEM port in the GPON system?
A: The specifications of the GEM port in the GPON system are as follows:
In the case of the MA5680T, 16 K (ID: 0-4095).
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In the case of the single PON port: 4096 (ID: 0-4095).
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Reserved: OMCIs (ID: 0-127), service configuration (ID: 128-3999), and others (ID:
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4000-4095 for multicast and broadcast services, and invalidity).
Each GEM port supports the mapping of up to eight streams and the priority ranges
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from 0 to 7.
Q: What is the difference between two DBA modes in the GPON, that is, SR and NSR?
A: The difference between the SR and NSR is whether the ONT supports the function of
reporting the bandwidth. If the ONT supports this function, the SR is used by default. The
ONT reports its bandwidth requirement and the OLT allocates the bandwidth to the ONT
according to the left bandwidth and a specific algorithm.
If the ONT does not support this function, the OLT allocates the bandwidth to the ONT
according to the percentage of idle frames filled in the ONT to the bandwidth.
Q: What are the specifications of the upstream VLANs and user VLANs of the MA5680T?
A: The specifications of the upstream VLANs and user VLANs of the MA5680T are as
follows:
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Copyright © Huawei Technologies Co., Ltd.
EchoLife HG861 GPON Terminal
Issue 01 (2009-07-30)