Checking the optical attenuation of Huawei switch ports

You can check optical attenuation on Huawei switch ports by using the display transceiver and display transceiver diagnosis commands to view TX/RX power and digital diagnostic monitoring information.Viewing Optical Module InformationTo check optical attenuation, you first need to access the optical module details:All ports: Use display transceiver to list all optical modules and their basic information, including type, wavelength, and vendor details .Specific port: Use display transceiver interface to view information for a particular port .Detailed diagnostics: Add the verbose parameter to see TX (transmit) and RX (receive) optical power, voltage, bias current, and temperature . Example command:CodeCopydisplay transceiver interface GigabitEthernet1/0/1 verbose This will show the digital diagnostic monitoring (DDM) data, which includes the current optical power levels. Optical attenuation can be inferred by comparing the TX power of the sending port and the RX power of the receiving port.Using Diagnostic CommandsHuawei switches also provide a dedicated diagnostic command:CodeCopydisplay transceiver diagnosis interface This command displays real-time optical power, signal quality, and potential faults for the module, helping you identify if attenuation is within acceptable limits .Interpreting Optical PowerTypical TX/RX ranges: For SFP modules, TX power usually ranges from -5 dBm to 0 dBm, and RX sensitivity ranges from -20 dBm to -3 dBm depending on the module type .High attenuation: If RX power is significantly lower than expected, it indicates excessive attenuation, possibly due to fiber length, connectors, or patch panels.Low attenuation or high RX power: May indicate a short link or incorrect module type.Additional TipsEnsure you are using Huawei-certified optical modules, as non-certified modules may provide inaccurate readings or cause interface issues .Use display interface to check link status and errors, which can correlate with optical attenuation problems .For a quick overview of all ports, display interface brief can help identify which ports are active and may need further optical inspection . By combining these commands, you can effectively monitor optical attenuation, verify link quality, and troubleshoot optical issues on Huawei switches.