Introduction for HUAWEI Access Network GPON Networking Protection

GPON network is the mainstream nowadays, GPON networking protection is very important. Below are introductions of networking protection.

Type B Single-homing Protection

·        Type B protection is implemented for different PON port on the same Huawei MA5800 GPON OLT or MA5600T GPON OLT

                                             

·        Advantages: The networking, OLT/ONU management, and service provisioning are simple.

·        Disadvantages: If the OLT is faulty, services are interrupted. Optical fibers are usually laid in the same pipe, and two optical fibers may be disconnected at the same time.

·        Application scenario: Protects important services of users, such as enterprise private line access services and base station private line access services.

Type B Dual-homing Protection

·        Type B dual-homing protection is implemented for PON ports of two OLTs

Advantages: Two backbone optical fibers are connected to two OLTs to implement remote disaster recovery.

Disadvantages: The networking is complex, the cost is high, and the OLT configuration is complex.

Application scenario: Protects important services such as enterprise private line access services and base station private line access services, especially in scenarios where remote disaster recovery is required.

Type C Single Homing Protection

Type C protection is similar to ring protection implemented for the OLT, ONU and optical splitter.

                                             

·        Advantages: The networking and OLT/ONU management is simple.

·        Disadvantages: If the OLT is faulty, services are interrupted. Optical fibers are usually laid in the same pipe, and two optical fibers may be disconnected at the same time.

·        Application scenario: Protects important services of users, such as enterprise private line access services and base station private line access services.

Type C Single Dual-homing Protection

·        In dual-homing networking, the two PON lines between the ONUs and two OLTs are in the active/standby state and cannot forward packets at the same time.

·        Advantages: When the upstream link of the OLT or OLT is faulty, services can be switched to the other OLT.

·        Disadvantages: The networking is complex, the cost is high, and the ONU management is complex.

·        Application scenario: Protects power supply as well as enterprise private line access services and base station private line access services

Does 100G OTN Tributary Board TSC Have Corresponding Cross-connect Board on Huawei OSN8800?

Huawei OSN 8800 100G tributary board is TSC, it has two functional version TN54 and TN55.  TN55TSC can be created as TQX on the NMS and  it can replace TN54TSC without any software upgrade. After substitution, the TN55TSC functions as the TN54TSC.

Below are Mapping between TSC board and OSN 8800 equipment:

Expect for equipment mapping, OSN 8800 T64 T32 T16 have their coresponding cross-connect boards, then how about TSC, does it also have coresponding cross-connect board? Answer is YES.

For an enhanced OptiX OSN 8800 T64 subrack, the TSC board must work with TNK2USXH+TNK2UXCT boards.

For an enhanced OptiX OSN 8800 T32 subrack, the TSC board must work with the TN52UXCH or TN52UXCM board.

For an OptiX OSN 8800 T16 subrack, the TSC board must work with the TN16UXCM board.

Thunder-link.com supplies full series OSN8800 OSN6800 boards with test report and technical supports, if you have any problem, you can contact us.
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How to deal with Abnormal Switching of SNCP service on ONT line board NS4 of Huawei OSN8800?

This is a case about handling abnormal switching of SNCP service on ONT line board NS4 of Huawei OSN8800.

Problem Description

100G line board TN54NS4 of a customer is configured with SNCP services. It is reported that multiple abnormal switching occurs on the live network, no fiber cut occurs on the optical cable, and the optical power is normal. Therefore, the root cause analysis needs to be performed.

The networking is as follows:

Alarm information:

ODU_SNCP_PS

Handling Procedure

1. Query the NMS alarms. It is found that the ODU_SNCP_PS alarm occurs multiple times and the SNCP switching occurs.

2. Check the current and historical alarms of the device. It is found that no fiber cut alarm is generated.

3. Continue to check the receive optical power of TN54NS4. It is found that the receive optical power is stable. Therefore, the switching is not caused by the bit errors caused by the power jitter.

4. According to the networking analysis (as shown in the following figure), it is found that SNCP switching occurs at a certain time, and services are switched from SNCP-to SNCP-protection. The switching cause may be caused by bit errors on the line. Because there is only one span between A-B, it can be confirmed that the problem is caused by this span.

5. The customer performed an OTDR test on the optical cable between the site A and the site B. It was found that the problem was caused by the reflection point of the optical cable.

6. The reflection point has a hop contact. After the connector is cleaned, the OTDR test shows that the reflection is normal and the SNCP switching is normal.

Root Cause

The fiber jumper connector is faulty. As a result, bit errors occur due to reflection and SNCP switching is triggered.

Suggestions and Summary

1. Alarm, performance, and optical power are the basic methods for locating WDM problems.

2. Common factors related to bit errors on the line side: a, non-linear effect; b, there is an abnormal reflection point on the line side

If you encounter same issue about NS4, you can refer to this article, it would be helpful.