Troubleshooting for Optical Modules on Huawei Switch

Many friends feedback that one problems occurred when using optical modules on switches, now we are providing the troubleshooting for the typical issues.

Optical module information cannot be displayed.

Services are running normally on a switch, but optical module information cannot be displayed.

1. Check whether the optical module is Huawei-certified. If it is not certified by Huawei, replace it with a Huawei certified one.
2. Remove and reinstall the optical module. If this resolves the fault, the optical module can continue to be used.
3. Check whether single-mode or multi-mode optical modules are used and whether the optical jumper type matches the transceiver modules.
4. Run the display version command to check the software version. If the version is earlier than V200R001C00SPC100, upgrading the software version to V200R001C00SPC100 or later is recommended.
5. If the software version is not upgraded, restart the switch.
6. If the fault persists, contact technical support of Huawei or the equipment supplier.

Transmit Power of an Optical Module Is Low

The transmit power of an optical module tested by an optical power meter is lower than the nominal transmit power.

1. Check whether bores of the optical module are dirty, and use a cotton swab to clean them if necessary. Then, re-test the transmit power. Cover unused optical modules with dust plugs.
2. If the transmit power remains low, replace the optical module or install it in another optical port to check whether it is faulty. If the optical module is faulty, send it to Huawei for repair or contact Huawei technical support.

How to choose Single-mode & Multi-mode Optical Modules

Multi-mode optical modules are applicable to short-distance transmission, while single-mode optical modules are applicable to long-distance transmission. Single-mode optical modules will be widely used in future.

NOTE:

Some single-mode optical modules need optical attenuators, but some do not need. This depends on the transmit/receive power of the optical module and the transmission distance.

Multiple types of Huawei devices can use the same type of optical module. For details, see the product hardware description.

Are Attenuators Required in the Case of Short-Distance Connection Using Single-Mode Optical Modules

Whether attenuators are required depends on the transmit power at the Tx end and the receive power range allowed at the Rx end. If the transmit power at the Tx end is beyond the receive power range allowed at the Rx end, attenuators are required. The path loss is small in short-distance transmission. If optical modules with a long transmission distance (generally more than 40 km) are used for short-distance connection, it is recommended that you use attenuators to reduce the receive power at the Rx end.

Can Optical Ports Connecting Two Switches Work Normally If Their Transmit/Receive Power Is Abnormal

When the power of optical ports connecting two switches is abnormal, either of the following situations occurs:

• When the transmit/receive power of the optical ports is too high, optical modules on the ports may be damaged. In this case, connect an attenuator to the optical modules.
• When the transmit/receive power of the optical ports is too low, error packets or packet loss may occur on the optical ports or the ports may be Down. In this case, you are advised to:

1. Check whether the fiber length between the two ports is within the maximum transmission range of the optical modules on the ports.
2. Check whether the fiber between the two ports is damaged.
3. Use optical modules with a longer transmission distance on the two ports.

When connecting switches through optical ports, pay attention to the following points:

• The optical modules used on both ends must have the same wavelength.
• The receive power must be within the range required by the optical modules.
• The transmission distance of an optical module is affected by the optical fibers connected to it. For example, when an OMXD30000 10GE SFP+ optical module uses OM1 multimode optical fibers, its transmission distance is 0.033 km. When this optical module uses OM3 multimode optical fibers, its transmission distance is 0.3 km.
• The optical modules used on both ends must have the same transmission speed, and the interface configurations on both ends must comply with related protocols.
• The type of optical modules used on the two ports is not restricted. For example, a port with an XFP optical module can communicate with a port with an SFP+ optical module, as along as they meet the preceding requirements.

Optical modules plays an important role in optical network, it will bring many troubles when it not working, in this passage, you’ve learnt several typical cases, contact with our technical team if your problem not solved yet.