Part Number Change Notice for 400G Cable & Transceiver Modules

Sep 24, 2025 - Part Number Change Notice for 400G Cable & Transceiver Modules FS announces a part number change for the optical modules and cables listed below. This is solely a product part number change announcement - functionality remains completely unaffected when using the new part numbers. The updated numbering system is designed to streamline the customer ordering process. 1. Direct Attach Cables (DACs) & Active Optical Cables (AOCs) Former Part Number Upgraded Part Number Date QSFP-DD-PCxx (0.5m-3m) QDD-400G-PCxxx (0.5m-3m) Mar 22, 2024 QDD-ACxx (1m-5m) QDD-400G-ACxxx (1m-5m) QSFP-DD-AOxx (1m-100m) QDD-400G-AOxxx (1m-100m) Q112-PCxx (0.5m-1.5m) QSFP-400G-PCxxx (0.5m-1.5m) Q112-ACxx (1m-3m) QSFP-400G-ACxxx (1m-3m) OSFP400-QDDPCxxx (0.5m-2m) OSFPFL-400G-QDDPCxxx (0.5m-2m) Q-2Q56PCxx (0.5m-3m) QDD-400G-2QPCxxx (0.5m-3m) QDD-2Q56ACxx (1m-5m) QDD-400G-2QACxxx (1m-5m) QDD-2Q56AOxx (1m-30m) QDD-400G-2QAOxxx (1m-30m) O56-2Q200G-PCxxx (1m-30m) OSFP-400G-2QPCxxx (1m-30m) Mar 14, 2024 OSFP400-2Q56AOxxx (3m-30m) OSFP-400G-2QAOxxx (3m-30m) Q-4Q56PCxx (0.5m-3m) QDD-400G-4QPCxxx (0.5m-3m) Mar 22, 2024 QDD-4Q56ACxx (3m-5m) QDD-400G-4QACxxx (3m-5m) QDD-4Q56AOxx (1m-50m) QDD-400G-4QAOxxx (1m-50m) Q-4Q28ACxx (3m) QDD-400G-4Q4xNACxxx (3m) QDD-4Q28AOxx (1m-20m) QDD-400G-4Q4xNAOxxx (1m-20m) Q-8S56PCxx (0.5m-3m) QDD-400G-8SPCxxx (0.5m-3m) QDD-8S56AOxx (1m-70m) QDD-400G-8SAOxxx (1m-70m) 2. QSFP-DD Modules Former Part Number Upgraded Part Number Date QSFPDD-SR8-400G QDD-SR8-400G Jan 18, 2024 QSFPDD-LR8-400G QDD-LR8-400G QSFPDD-FR4-400G QDD-FR4-400G QSFPDD-LR4-400G QDD-LR4-400G QSFPDD-ER8-400G QDD-ER8-400G QSFPDD-DR4-400G QDD-DR4-400G QSFPDD-PLR4-400G QDD-PLR4-400G Mar 14, 2024 QSFPDD-XDR4-400G QDD-XDR4-400G 3. QSFP112 Modules Former Part Number Upgraded Part Number Date Q112-DR4-400G QSFP112-DR4-400G Mar 14, 2024 Q112-SR4-400G QSFP112-SR4-400G Q112-FR4-400G QSFP112-FR4-400G Q112-LR4-400G QSFP112-LR4-400G Q112-XDR4-400G QSFP112-XDR4-400G Mar 22, 2024 4. Transmission Modules Former Part Number Upgraded Part Number Date QSFPDD-ZR-400G QDD-ZR-400G Apr 14, 2025 QSFPDD-ZRP-400G QDD-ZRP-400G QDD-ZRP-400G-HT QDD-ZRPH-400G 5. Loopback Modules Former Part Number Upgraded Part Number Date QSFP-DD-LB QDD-LOOP-400G Jan 18, 2024 Customer Impact of Change and Recommended Action No functional changes - There is no change to the fit or function of the products. Customers may receive either label until the old inventory is depleted. No action required - No action is needed by customers. Questions? - Please Contact Us for any questions or concerns.

100G QSFP28 & 400G QSFP-DD Coherent Module Installation Guide

Aug 06, 2025 - 100G QSFP28 & 400G QSFP-DD Coherent Module Installation Guide 1. Overview 1.1 Declaration This guide describes the general handling measures and precautions when handling 100G/400G coherent optical modules to ensure that the risk of damage is reduced during handling. 1.2 Optical Module Appearance Description 1.2.1 100G Coherent Optical Module image.png Figure 1 1 Pull Tab 2 Dust cap 3 Module body 4 Unlock structure 5 Golden Fingers 6 Duplex LC/UPC interface 1.2.2 400G Coherent Optical Module image.png Figure 2 1 Pull Tab 2 Dust cap 3 Module body 4 Unlock structure 5 Golden Fingers 6 Duplex LC/UPC interface 1.3 Optical Module's Key Functions or Parameters 1.3.1 100G Coherent Optical Module Product 100G ZR (Commercial) 100G ZR (Industrial Grade) Part Number QSFP-ZR-100G QSFP-ZR-100G-S QSFP-ZR-100G-I QSFP-ZR-100G-S-I Power Consumption (Typical) ≤5.5W ≤5.5W ≤6W ≤6W Power Consumption (maximum) / / / / Operating Temperature (℃) 0~70 0~70 -40~85 -40~85 Transmission Distance 80km (unamplified) 120km (amplified) 300km (amplified and DCM) 80km (unamplified) 120km (amplified) 300km (amplified and DCM) 80km (unamplified) 120km (amplified) 300km (amplified and DCM) 80km (unamplified) 120km (amplified) 300km (amplified and DCM) FEC Host Side FEC Mode：RS (528,514) Line Side FEC Mode：SC Host Side FEC Mode：RS (528,514) /RS (255,239) Line Side FEC Mode：SC/RS (255,239) Host Side FEC Mode：RS (528,514) Line Side FEC Mode：SC Host Side FEC Mode：RS (528,514) /RS (255,239) Line Side FEC Mode：SC/RS (255,239) Optical Power (dBm) -8~-4 -8~-4 -8~-4 -8~-4 Received Optical Power (dBm) -30~3 -30~3 -30~3 -30~3 Management Interface SFF-8636 CMIS SFF-8636 CMIS Modulation DP-DQPSK DP-DQPSK DP-DQPSK DP-DQPSK Wavelength Range (nm) C-Band 5THz DWDM Tunable C-Band 5THz DWDM Tunable C-Band 5THz DWDM Tunable C-Band 5THz DWDM Tunable RX OSNR Sensitivity (dB) 35 35 35 35 CD Tolerance（ps/nm） 2400 2400 2400 2400 Key Features Low Power Consumption with ≤5.5W Tested in Switches for Superior Performance and Reliability DWDM for Multiple Applications over One Duplex Fiber Up to 300Km Amplified Extended for DWDM Transmission Support 4x 100G Breakout to 400G ZR+ for Net Expansion Compact Size, Cost-optimized Coherent WDM Line Interface Hot Pluggable QSFP28 MSA Compliant Digital Optical Monitoring for Strong Diagnostics Low Power Consumption with ≤6W Tested in Switches for Superior Performance and Reliability DWDM for Multiple Applications over One Duplex Fiber Up to 300Km Amplified Extended for DWDM Transmission Support 4x 100G Breakout to 400G ZR+ for Net Expansion Compact Size, Cost-optimized Coherent WDM Line Interface Hot Pluggable QSFP28 MSA Compliant Digital Optical Monitoring for Strong Diagnostics 1.3.2 400G Coherent Optical Module Product 400G ZR 400G ZR+ Part Number QSFPDD-ZR-400G QSFPDD-ZRP-400G QDD-ZRPH-400GM QDD-ZRP-400G-HT Power Consumption (Typical) 18.5W 22.5W 22.5W Power consumption (maximum) 18.5W / / Operating Temperature (℃) 0~70 0~70 0~70 Transmission Distance ≤40km (unamplified) ≤120km (amplified) ＞600km ＞600km FEC CFEC OFEC，CFEC OFEC，CFEC Optical Power (dBm) -13~-9 -13~-7 -6~1 Received Optical Power (dBm) unamplified： -20~0dBm amplified： Full Rx OSNR tolerance: -12~0dBm Extended range: -15~1dBm unamplified： 400G 16QAM:-23~0dBm 300G 8QAM:-26~0dBm 200G QPSK:-30~0dBm 100G QPSK:-32~0dBm 400G ZR:-20~0dBm amplified： Full Rx OSNR tolerance: -12~0 Extended range: ZRx00-OFEC：-18~3 400G ZR：-15~1 unamplified： 400G 16QAM:-23~0dBm 300G 8QAM:-26~0dBm 200G QPSK:-30~0dBm 100G QPSK:-32~0dBm 400G ZR:-20~0dBm amplified： Full Rx OSNR tolerance: -12~0 Extended range: ZRx00-OFEC：-18~3 400G ZR：-15~1 Business Model 400G 4x100G 400G 16QAM 300G 8QAM 200G QPSK 100G QPSK 400G ZR 400G 16QAM 300G 8QAM 200G QPSK 100G QPSK 400G ZR Modulation 16QAM 16QAM/8QAM/QPSK 16QAM/8QAM/QPSK Wavelength Range (nm) 1528.77~1566.52nm 1528.77~1567.13nm 1528.77~1567.13nm RX OSNR Sensitivity (dB) 26dB 400G 16QAM:23.5 300G 8QAM:20 200G QPSK:15 100G QPSK:12 400G ZR:26 400G 16QAM:23.5 300G 8QAM:20 200G QPSK:15 100G QPSK:12 400G ZR:26 CD Tolerance（ps/nm） 2400 400G 16QAM:12000 300G 8QAM:18000 200G QPSK:24000 100G QPSK:48000 400G ZR:2400 400G 16QAM:12000 300G 8QAM:18000 200G QPSK:24000 100G QPSK:48000 400G ZR:2400 Key Features Max. Power Consumption 18.5W Tested in Targeted Switches for Superior Performance, Quality, and Reliability 400G 16QAM Modulation Formats Up to 120km over SMF Supports Multiple Bit Rates and Forward Error Correction (FEC) Schemes Compliant with 400ZR OIF MSA for flexible configurations and seamless optical internetworking Hot-pluggable QSFP-DD Form Factor Ideal for 400G single-span metro DCI, business services, and broadband backhaul including radio and PON Max. Power Consumption 22.5W Tested in Targeted Switches for Superior Performance, Quality, and Reliability Adapt the Wavelength to Offer Greater Flexibility to a Growing Network Coherent 400G/300G/200G/100G Optical Interface Based on Open ZR+ MSA Full Flexgrid C-band Tunable: 191.3~196.1THz Modulation: DP-QPSK, DP-8QAM, DP-16QAM Hot-pluggable QSFP-DD Form Factor Ideal for 400G single-span metro DCI, business services, and broadband backhaul including radio and PON Max. Power Consumption 22.5W Tested in Targeted Switches for Superior Performance, Quality, and Reliability Hot-pluggable QSFP-DD Form Factor 7nm coherent DSP ASIC functionality Coherent 400G/300G/200G/100G optical interface based on OpenZR+ MSA Full flexgrid C-band tunable: 191.3~196.1THz Modulation: DP-QPSK, DP-8QAM, DP-16QAM Transmission reach 450km at 400G, with extended reaches at lower data rates 1.4 Optical Module User Guide Example Diagram image.png (Diverse ports for 40-channel DWDM Mux Demux) image.png (400G connections in Data center) Instructions for Use When connecting a coherent optical module to a Mux/Demux, ensure that the module’s wavelength precisely matches the channel wavelength of the Mux/Demux. Do not insert the module into a port with a mismatched wavelength. When inserting a coherent optical module into a switch, make sure that its total power consumption is within the rated power capacity of the switch port. As a general practice, fully populating all ports with high-power modules is not recommended, as it may negatively impact heat dissipation. 2. Safety Risk Notification 2.1 Precautions Icon Text Description image.png Keep dry image.png Do not disassemble or modify image.png Please wear anti-static gloves image.png Do not look into fiber ports image.png The module may only be installed or replaced by qualified personnel The theoretical mating cycle limit for optical modules typically ranges from 500 to 2000 insertions. Frequent removal and reinsertion of 100G/400G coherent optical modules can reduce their service life. Therefore, such operations should be avoided unless absolutely necessary. Before installing or removing a 100G/400G coherent optical module, always disconnect all fiber patch cables. Never install or remove the module while the fiber is still connected, as this may cause damage to the patch cables or the module itself, potentially degrading transmission performance. After removing the fiber, protect the pluggable module by inserting a clean dust cap. Before reconnecting the fiber to another 100G/400G coherent module, ensure that the optical surface of the fiber is properly cleaned. Prevent dust or other contaminants from entering the optical port of the module, as contamination can impair the performance of optical components. Coherent optical modules are highly sensitive to electrostatic discharge (ESD). Always use an ESD wrist strap or equivalent grounding device/anti-static gloves during the installation or removal process to avoid damage. When interconnecting two coherent optical modules, it is recommended to use the same model of 100G/400G coherent modules on both ends to ensure compatibility and optimal performance. 2.1.1 ESD Prevention Measures[1] Note: Optical modules are electrostatic discharge (ESD) sensitive devices. Always use an ESD wrist strap or a similar individually grounded device when handling or touching the module. Optical modules are susceptible to electrostatic discharge (ESD), which can damage sensitive integrated circuits. Personnel handling the modules should wear ESD-protective wrist straps that are properly grounded. Work surfaces and benches should also be ESD-protected and connected to a common grounding point. 2.2 Operating Temperature of the Optical Module To ensure the long-term stability and reliable performance of optical modules, it is essential to operate them within the specified temperature range. Regular monitoring of the module’s operating status and maintaining adequate system cooling can significantly extend the module’s service life. The operating temperature range is typically defined by the manufacturer and generally falls into two categories: Commercial grade: 0°C to 70°C Industrial grade: -40°C to 85°C The effects of too high or too low temperature on the optical module are as follows: High Temperature Effects Signal attenuation: Elevated temperatures can increase signal loss, degrading optical transmission quality and potentially causing data errors. Component aging: High temperatures accelerate the aging of internal electronic components, reducing the module’s overall lifespan. Increased failure risk: Excessive heat can impair the performance of the transmitter and receiver, potentially leading to module failure or permanent damage. Low Temperature Effects Startup issues: At excessively low temperatures, optical modules may fail to start or operate correctly, especially outside the industrial-grade range. Unstable optical power: Low temperatures may cause instability in the laser’s output power, which can affect data transmission performance. To ensure reliable performance, optical modules must operate within their specified temperature range. Operating outside of this range may lead to performance degradation or even permanent damage to the module. Several factors influence the module’s case and surface temperature, including the ambient temperature of the operating environment, airflow, cage design, and heat sink integration. All of these contribute to the thermal behavior of the module. When physically removing a module from a port, it should only be done when the module has cooled down to a comfortable handling temperature. Typically, the case temperature of an optical module is approximately 10 to 15°C higher than the ambient temperature. For example, in a 45°C environment, the case temperature can easily reach 60°C or higher, making the metal housing hotter than recommended handling limits. These modules are designed to dissipate heat efficiently through conduction via the host platform’s cage and any attached heat sink, provided that adequate airflow is maintained. 3. Installing 100G/400G Coherent Optical Modules 3.1 Install/Replace Optical Module[2] Note: QSFP-DD ports can usually use QSFP-DD/QSFP28 optical modules, while QSFP28 ports cannot use QSFP-DD optical modules. To install an optical module, follow these steps: 1. Wear an ESD wrist strap and ensure it is properly grounded to the chassis or rack ground point. 2. Remove the optical module from its protective packaging. 3. Check the label on the body of the 100G/400G coherent optical module to verify that the module model matches your network requirements. 4. Hold the module with the identifier label facing downward. Align the module with the front of the platform port, and carefully slide it into the socket until it makes contact with the electrical connector. On some platforms, the cages for 100G/400G coherent modules are mounted upside down. In such cases, the identifier label must face upward during insertion. (As shown in Figures 3 to 4) Figure 3 Install 100G Coherent QSFP28 Transceiver Module 1-1.jpg Figure 4 Install 100G Coherent QSFP28 Transceiver Module 1-2.jpg 5. Firmly press the front end of the optical module with your thumb to ensure it is fully seated in the QSFP28/QSFP-DD cage. If the latch is not fully engaged, the 100G/400G coherent optical module may become accidentally disconnected. 6. Do not remove the dust cap until you are ready to connect the fiber. 7. Always clean the fiber connector end face using an appropriate fiber cleaning tool. This step should be performed every time before inserting the fiber into the module’s optical receptacle. 3.2 Install/Replace Fiber Optic Patch Cables 1. Verify that the labels on the fiber patch cords are correct, legible, and neatly applied. If any label is unclear or difficult to identify, it should be replaced to avoid connection errors. 2. Check the condition of the fiber connection. Before removal, ensure that the patch cord is properly connected and free from bending or other physical damage. 3. When removing the fiber patch cord (e.g., replacing an LC patch cord), wear anti-static gloves. Use the index finger and thumb of one hand to hold both sides of the 100G/400G coherent optical module firmly. With the other hand, use your index finger and thumb to grip both sides of the LC connector, keeping the patch cord in a horizontal position (avoid angling or twisting). Gently pull the LC connector straight back with light force. (Do not pull on the fiber itself. Remove the connector gradually to avoid applying excessive stress to the fiber.) Figure 5 Duplex LC fiber installation 2-1.jpg 4. After removing the fiber patch cord, remove the dust cap from the new fiber patch cord. Hold the new fiber connector body with your index finger and thumb on both sides, align the key on the connector with the keyway on the optical module, and insert the fiber patch cord horizontally (avoid angling) into the module until the locking mechanism clicks into place. Ensure the connector is clean before insertion. 5. Once the link is fully established, the LED indicator will light solid green. 6. After replacing the fiber patch cord, store the old fiber patch cord in an anti-static packaging. 4. Removing 100G/400G Coherent Optical Module 4.1 Remove Optical Module[3] Note: The form-factor pluggable 100G/400G coherent optical modules are designed with a pull-tab release mechanism. To remove the optical module, follow these steps using the pull-tab: 1. Wear an ESD wrist strap and ensure it is properly grounded to the chassis or rack ground point. 2. Disconnect the fiber connector from the optical module. Keep the fiber connector clean. 3. For modules equipped with a pull-tab latch: Immediately insert a dust cap into the optical port of the module. Grasp the label with your fingers and gently pull the pull-tab to release the module from the socket. Slide the module out of the socket by holding the pull-tab only; avoid touching the pluggable metal surfaces. 4. Place the module on an ESD-safe workstation or work area and allow it to cool down before placing it into an anti-static bag. Figure 6 Removing QSFP28 Transceiver Modules 3-1.jpg 5. Cleaning and Maintenance 5.1 End Face Treatment and Cleaning Optical modules can be damaged by exposure to current surges and overvoltage events. Please ensure that exposure is limited within the conditions defined by the absolute maximum ratings. Always follow standard electrostatic discharge (ESD) precautions for handling sensitive devices. Optical modules are equipped with dust caps on both the electrical and optical ports. When fibers are not connected, dust caps on the optical ports should always be kept in place. The fiber connector has a recessed connector end face, which becomes exposed when neither fiber nor dust cap is present. Important Note 1: Always keep the dust caps for both fiber connectors and optical modules. Important Note 2: Before inserting the fiber, clean both the module end face and the fiber patch cord end face thoroughly to prevent contamination. Dust caps help maintain the cleanliness of optical components during transportation. Standard cleaning tools and methods should be used during installation and maintenance. The use of liquids is prohibited. Important Note 3: Approximately 80% of optical module link issues are related to dirty fiber connectors. Figure 7 Module End-Face Inspection image.png Figure 8 Module End-Face Cleaning 4-1.jpg 5.2 Maintain Fiber Optic Jumpers[4] Fiber Patch Cord Maintenance: When unplugging the fiber from the optical module, place rubber protective caps on both the module port and the fiber end face. Secure the fiber to avoid stress on the connector. When connecting the fiber to the module, make sure the fiber is supported so that its own weight does not hang freely from the connector. Never allow the fiber to dangle unsupported from the connector. Do not bend the fiber beyond its minimum bend radius. Exceeding the minimum bend radius may damage the fiber and cause difficult-to-diagnose problems. Frequent plugging and unplugging of fibers into optical instruments can damage the instruments and incur high repair costs. Use a short fiber extender cable connected to the optical device. Any wear caused by frequent mating cycles will be absorbed by the extender cable, which is easier and less expensive to replace than the instrument itself. Keep fiber connections clean. Tiny deposits of oil and dust inside the optical module or fiber connector ferrules can cause optical loss, reduced signal power, and intermittent connection issues. To clean the optical module receptacle, use appropriate fiber cleaning tools such as the ATC-NS-125 Fiber Adapter Cleaning Stick (Part No. 190742). Follow the instructions provided with your cleaning kit. After cleaning the optical module, ensure the fiber connector end face is clean. Only use approved alcohol-free fiber cleaning kits, such as the Cletop-S® Fiber Cleaner. Follow the instructions provided with your cleaning kit. Figure 9 Patch Cord End-Face Inspection image.png Figure 10 Patch Cord End-Face Cleaning image.png 6. Product Warranty FS assures our customers that any damage or defects caused by our manufacturing process are covered by a free return policy within 30 days from the date of receipt. For optical modules, we also offer a replacement service for any quality issues occurring within one year. (Note that The above return and replacement services do not apply to customized products.) Warranty: All optical modules come with a limited warranty against material or workmanship defects for a period of 5 years. For more detailed warranty information, please refer to https://www.fs.com/policies/warranty.html Returns: If you wish to return a product, information on the return process can be found at the following website https://www.fs.com/policies/day_return_policy.html 7. Security and Compliance This device has been tested and found to comply with the limits for a Class B digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in residential installations. This device generates, uses, and can radiate radio frequency energy, and if not installed and used in accordance with the instructions, may cause harmful interference to radio communications. FS.COM hereby declares that this product complies with the 2014/30/EU Directive. A copy of the EU Declaration of Conformity is available at: https://www.fs.com/compliance-center.html Compliant with Class 1 Laser standards. image.png Figure 11 Class 1 Laser compliant To comply with the above laser safety standards, these products should be installed and used together with certified Class 1 devices manufactured by vendors approved by FS. 8. Common Issue Troubleshooting 8.1 Optical Module Insertion and Removal Issues 8.1.1 Optical Module Latch Issues Issues with optical module latches may include poor physical connection, interface mismatch, or difficulty during insertion and removal. Addressing these problems requires a comprehensive approach considering hardware design, connectors, and protocols. Below are some suggested solutions for common optical module latch issues: ①Locate the module’s release mechanism; The unlocking position of 100G/400G coherent optical modules is generally on the left and right sides of the module. ②Insert a pair of tweezers or a stainless steel card between the module latch and the switch cage, then apply horizontal force to gradually pull the module out. ③Be careful during this process to avoid scratching the module or damaging the switch port. 8.1.2 Optical Module Installation Issues Pre-installation Inspection: Check the gold fingers of the optical module to ensure they are clean and shiny. Inspect the device ports for any physical damage. Examine the optical module’s port interface to confirm there are no visible damages. Verify that the ferrules of the patch cords are not damaged. Installation issues may arise from various factors including physical connection, connectors, and device compatibility. Below are common problems and recommended solutions: 1. Optical Module Installation Issue: Problem: The optical module is not fully seated in the device slot, causing damage to the device port or the module itself. Solution: When inserting the module, ensure it is firmly pushed into the slot and the latch engages properly. Align the module connector correctly and gently push it into the slot. A “click” sound indicates proper insertion and that the locking mechanism is engaged. Without this, vibration or shocks may cause disconnection or loosening. 2. Optical Module Installation Issue: Problem: The LC patch cord is not properly inserted into the optical module, causing damage to the module port or the patch cord. Solution: When installing the LC patch cord, hold the connector body with your index finger and thumb on both sides, align the key on the connector with the keyway on the optical module, and insert the patch cord horizontally (do not angle it) until the locking mechanism clicks. 8.2 Optical Module (Patch Cord, Adapter) End-Face Contamination Issues Contamination of the optical module end-face is a common issue that adversely affects optical communication performance. Below are some recommendations for handling end-face contamination: 1. Proper Use of Inspection and Cleaning Tools: Use end-face inspection microscopes, LC cleaning pens, and other appropriate tools to inspect and clean the connector end-faces of optical modules and fiber patch cords. Inspection tools provide a clearer view of microscopic contamination and defects on the connector end-face. 2. Environmental Control: Ensure the connection and storage environment for fiber connectors is kept clean. Avoid performing connection operations in environments with excessive dust, smoke, or other contaminants. 3. Regular Cleaning: Clean the optical module and LC patch cord end-faces regularly, especially before plugging or unplugging the modules or patch cords. 4. Avoid Touching Connector End-Faces: Do not touch connector end-faces directly during handling. Always wear an ESD wrist strap connected to a proper ground point or wear anti-static gloves. 5. Use Dust Caps: When optical modules or LC patch cords are not in use, protect the connector end-faces with the appropriate dust caps to prevent contamination. 6. Proper Storage: Store optical modules in a dry, clean environment, away from dust and humidity. 7. Operator Training: Train personnel on proper handling and maintenance of optical modules and LC patch cords to ensure all operators understand how to maintain clean connector end-faces effectively. When addressing end-face contamination, always refer to the relevant device and connector operation manuals, and follow the product compatibility recommendations and specifications. 8.3 Optical Module Detector Breakdown and Saturation Issues 8.3.1 Detector Breakdown Issue Detector breakdown: when the optical module’s detector is exposed to excessively strong optical signals, causing it to malfunction or produce unstable output signals. Solutions: Reduce optical input power: If the detector receives an excessively strong signal, reduce the input power by using an appropriately rated optical attenuator or by increasing the transmission distance. Replace the module: If the detector has already been damaged by breakdown, the module must be replaced with a new one. 8.3.2 Detector Saturation Issue Detector saturation: when the detector’s output signal becomes saturated due to strong input optical signals, meaning the output no longer accurately reflects variations in the input signal power. Solutions: Reduce optical input power: Saturation is usually caused by excessively strong optical signals; reducing input power via an optical attenuator or increasing transmission distance can alleviate the problem. Use linear output detectors: Some optical modules employ detectors with linear output characteristics, where the output signal is proportional to the input optical power, providing more accurate signal measurement and reducing saturation issues. IX. Appendix Part Number and Description Form Factor Part Number Description QSFP-DD QSFPDD-ZR-400G Cisco QDD-400G-ZR-S Compatible QSFP-DD DCO 400G DWDM Tunable Coherent ≤120km DOM Duplex LC/UPC SMF Optical Transceiver Module for Transmission QDD-ZRP-400G-HT Arista Networks 400GBASE-ZRP Compatible QSFP-DD High-Power (Bright) DCO 400G DWDM Tunable Coherent ＞120km DOM Duplex LC/UPC SMF Optical Transceiver Module for Transmission QSFPDD-ZRP-400G Arista Networks 400GBASE-ZRP Compatible QSFP-DD DCO 400G DWDM Tunable Coherent ITU CH13-CH61 50GHz >120km DOM Duplex LC/UPC SMF Optical Transceiver Module for Transmission QDD-ZRPH-400GM Ciena 180-3360-900 Compatible QSFP-DD High-Power (Bright) DCO 400G DWDM Tunable Coherent ＞120km DOM Duplex LC/UPC SMF Optical Transceiver Module for Transmission QSFP28 QSFP-ZR-100G Generic Compatible QSFP28 DCO 100G DWDM C-band Tunable Coherent 80km DOM Duplex LC/UPC SMF Optical Transceiver Module for Transmission QSFP-ZR-100G-S Generic Compatible QSFP28 DCO 100G DWDM C-band Tunable Coherent 80km DOM Duplex LC/UPC SMF Optical Transceiver Module for Transmission QSFP-ZR-100G-S-I Generic Compatible QSFP28 DCO 100G DWDM C-band Tunable Coherent 80km DOM Duplex LC/UPC SMF Optical Transceiver Module for Transmission(Industrial) QSFP-ZR-100G-I Cisco Compatible QSFP28 DCO 100G DWDM C-band Tunable Coherent 80km DOM Duplex LC/UPC SMF Optical Transceiver Module for Transmission(Industrial) References [1][2][3] Cisco Optical Transceiver Handling Guide（https://www.cisco.com/c/dam/en/us/td/docs/interfaces_modules/transceiver_modules/installation/guide/optical-transceiver-handling-guide.pdf） [4] Removing and Installing Transceivers and Fiber-Optic Cables（https://www.juniper.net/documentation/us/en/hardware/mx10008/topics/topic-map/mx10008-replace-tranceivers.html）

Jul 15, 2025 - For details, please click the attachment icon below to view or download for a good reading experience or resources.

400G QSFP-DD Coherent Optical Module Troubleshooting Guide

Jun 30, 2025 - 400G QSFP-DD Coherent Optical Module Troubleshooting Guide 1. Document Background With the rapid growth of AI computing, large-scale cloud services, 5G, and IoT applications, there is an increasing demand for high-bandwidth, low-latency, and highly reliable optical transmission. As a result, coherent optical communication has become a mainstream solution in the industry. In application scenarios such as Data Center Interconnect (DCI), telecom backbone networks, metro networks, and submarine cable systems, 400G coherent optical modules have emerged as a key enabling technology. Currently, most 400G coherent modules on the market adopt modulation formats such as DP-16QAM and DP-QPSK, and rely on Digital Signal Processing (DSP) technology to compensate for transmission impairments such as fiber loss, chromatic dispersion, and nonlinear effects. Typical 400G coherent module types include: CFP2-DCO (Digital Coherent Optical): Widely used in carrier networks, typically deployed in conjunction with complex telecom transport platforms. QSFP-DD/ZR/ZR+: Designed for data center interconnect and metro transmission, these modules are commonly used in open, disaggregated network architectures. Leading vendors such as Ciena, Cisco, Infinera, Huawei, and Nokia have each introduced their own 400G coherent solutions, each with unique design characteristics. However, they all face similar technical challenges and failure types. Due to the tight coupling between CFP2-DCO modules and proprietary optical transport platforms, CFP2-based solutions often lack interoperability across vendors. This guide focuses on practical issues and corresponding solutions encountered when deploying QSFP-DD 400G ZR coherent modules in real-world service environments. 2. Overview of QSFP-DD ZR 400G Coherent Module Specifications QSFP-DD 400G coherent modules available on the market can generally be classified into three versions: QSFP-DD-ZR-400G – Standard 400G coherent ZR module QSFP-DD-ZRP-400G – Enhanced ZR+ coherent module QSFP-DD-ZRP-400G-HT – High-power version of the ZR+ coherent module The main differences among these versions are outlined below. Parameter QSFPDD-ZR-400G QSFPDD-ZRP-400G QDD-ZRP-400G-HT Part Number QSFPDD-ZR-400G QSFPDD-ZRP-400G QDD-ZRP-400G-HT Data Rate 400G:478.750Gbps（59.84375GBd GBd） 400G:478.750Gbps, (59.84375GBd)/481.1Gbps, (60.14GBd) 300G:360.8Gbps, (60.14GBd) 200G:240.6Gbps, (60.14GBd) 100G:120.3Gbps, (30.07GBd) Modulation Format DP-16QAM 400G:DP-16QAM 300G:DP-8QAM 200G:DP-QPSK 100G:DP-QPSK Split Ability Not supported Not supported FEC Type Concatenated FEC (CFEC) CFEC/OFEC【CFEC:478.750Gbps】 Max pre-Correction Error code 1.25x10(-2) 1.25x10(-2) or 2.0x10(-2) Wavelength Range 1567.13 ~ 1528.77 nm Frequency Range 191.3 THz ~ 196.1 THz Transmitter Output Power 400G ZR: -13~-9dBm(EDFA) 400G ZR Gray: -9~-6dBm 400G:-13~-9dBm 300G:-10~-6dBm 200G:-9~-5dBm 100G:-8~-4dBm ≤–30 dBm （off） 400G ZR & 400G ZR+(120km):-10~1 dbm 400G ZR & 400G ZR+ Gray:3~5 dbm RX Sensitivity ≤–20 dBm 400G ZR+: -22dBm 400G ZR: -20dBm 400G ZR+: -22dBm 400G ZR: -20dBm Latency（us） 7.8 400G:7.8/4.7 300G:5.3 200G:6.6 100G:10.5 400G:8/5 300G:6 200G:7 100G:11 Transmission Distance 120 km （amplified） 40 km (unamplified) 400G: 40km (unamplified)/120km (amplified) 400G: 40km (unamplified)/500km (amplified) 300G: 50km (unamplified)/900km (amplified) 200G: 70km (unamplified)/2000km (amplified) 100G: 80km (unamplified)/>2000km (amplified) 400G: 80km (unamplified)/140km (amplified) 400G: 92km (unamplified)/700km (amplified) 300G: 104km (unamplified)/1050km (amplified) 200G: 120km (unamplified)/1400km (amplified) 100G: 128km (unamplified)/2800km (amplified) Maximum Power Consumption (W) 18 22.5 22.5 Operating Temperature Commercial grade: 0~70℃ 3. Overview of Physical Layer Interface Parameters for Coherent Optical Modules As a key component of the physical layer, optical modules may exhibit various physical-layer-related issues during operation. Before troubleshooting physical layer interface errors, it is important to first understand the relevant physical interface parameters of 400G coherent optical modules. Common interface management standards and protocols include: Common Management Interface Specification for high-speed optical modules OIF-CMIS-05.2.pdf High-speed optical module SFF Management Specification Extension SFF-8024_R4.12.pdf Protocols developed by the Institute of Electrical and Electronics Engineers (IEEE) IEEE Standards Association 3.1 Introduction to 400G Coherent High-Speed Optical Module Form Factors Common form factors for 400G high-speed optical modules include the following: QSFP-DD: Quad Small Form-factor Pluggable Double Density, a double-density, four-channel small form-factor pluggable module. CFP2: C Form-factor Pluggable 2, the second-generation C-form-factor pluggable module. Each module, regardless of its form factor, contains an EEPROM that stores information about the module’s functionality as well as various mandatory and optional register sets used for querying or controlling different aspects of the module. The content of the public EEPROM area is typically defined by the CMIS protocol and the SFF-8024 specification. It is important to note that different devices may use different commands or methods to access EEPROM information depending on their implementation. Since CFP2 modules are currently predominantly used in telecom optical transport platforms, where the platform and module are tightly integrated and not decoupled, each vendor’s platform only supports its own CFP2 coherent modules. Therefore, this document focuses solely on QSFP-DD coherent modules for the purpose of study. 3.2 Overview of General EEPROM Interface Information As a first-layer physical component, high-speed optical modules must have internal EEPROM information that complies with relevant specifications to perform their intended functions. The defined content of this information is described in the corresponding version of the CMIS standard. Below is a description of the key information bytes. 3.3 Overview of 400G Coherent High-Speed Optical Module Form Factor Information In the module’s EEPROM, the first byte indicates the module form factor, which can be referenced in SFF-8024 Table 4-1, "Identifier Values". Key values include: 0x11: Indicates QSFP28 or later modules with the SFF-8636 management interface, applicable to QSFP28 and QSFP56 modules implementing the SFF-8636 specification. 0x18: QSFP-DD Double Density 8X Pluggable Transceiver, used for QSFP-DD modules with eight 50G or 100G channels (totaling 400G or 800G) featuring a double-density gold finger. 0x19: OSFP 8X Pluggable Transceiver, for OSFP modules with eight 50G or 100G channels (totaling 400G or 800G). The QSFPDD-400G-ZR module is QSFPDD package, and the value of Byte00 address should be defined as 0x18. 3.4 Introduction to CmisRevision The CMIS protocol defines the interface management specification for QSFP-DD modules and has undergone multiple version iterations. The latest version has been updated to CMIS 5.2. When manufacturers define values for management interface addresses, they should comply with the appropriate protocol version. Byte 01 address specifies the CMIS revision version; a value of 0x00 generally indicates that no CMIS version has been specified. 3.5 Key Parameters Including Product Interface Type, Host, and Media Interface IDs To enable the port to recognize the characteristics of the inserted module, the EEPROM of coherent 400G optical modules contains a standardized set of data describing the module features. The host and media interface fields describe the Ethernet technology types implemented by the module. The 400G Type classification can be referenced as follows: image.png image.png The 400G coherent module is a single-mode module, and 0x02 should be defined at Byte0x85. 3.6 Digital Diagnostic Monitoring (DDM/DOM) DDM/DOM is a critical function for monitoring optical modules and troubleshooting issues. It provides real-time feedback on key parameters such as temperature, voltage, current, transmit power, and receive power of the module. Each parameter plays a vital role in reflecting the module’s current operating status. Temperature: The module’s operating temperature should remain within an appropriate range and not be excessively high. Typically, there are two temperature grades: commercial and industrial. Commercial grade: 0°C to 70°C Industrial grade: -45°C to 80°C Due to higher power consumption, 400G coherent optical modules generate considerable heat during operation. Optical modules are temperature-sensitive devices; excessive temperature can severely degrade module performance and impact signal transmission quality. Operating Voltage: This is the voltage required for the module to start normally, typically between 3.135V and 3.465V, with 3.3V as the default. Insufficient power supply voltage may disrupt the module’s startup sequence, causing timing errors and malfunction of underlying logic, preventing the module from functioning correctly. Bias Current: The bias current refers to the laser’s operating current, not the module’s overall current. Different 400G coherent modules have varying bias currents. The laser current indicates the laser’s operational status. A bias current of 0 mA suggests that the module is unpowered or the laser is faulty. Analysis should then focus on the laser. Typically, when the laser current reaches 1.5 times its threshold current, it is considered that the laser’s lifetime has ended. Transmit (TX) and Receive (RX) Optical Power: TX and RX power are important parameters reflecting the optical power budget of the module. They help estimate link attenuation, assess the module’s current status, and evaluate performance. TX and RX power must operate within the device’s normal range; exceeding threshold limits may trigger optical power alarms and adversely affect transmission services. 3.7 FEC Configuration and Negotiation Forward Error Correction (FEC) is an error control method that encodes the signal before transmission by adding redundant information based on a specific algorithm. At the receiver, the signal is decoded using a corresponding algorithm to detect and correct errors generated during transmission. For 400G coherent optical modules, the pre-FEC bit error rate (BER) requirement typically ranges from 1 to 2 × 10⁻². Manufacturers generally design modules with performance well above this threshold to ensure error-free data transmission throughout the link. To maintain transmission quality, FEC is usually enabled. Please note that when FEC is enabled, the FEC types on both ends of the link must be consistent. During operation at certain data rates, there may be FEC compatibility issues within the same product line due to differences in encoding versions over time. The Reed-Solomon RS-FEC (544,514) algorithm adds 30 bits of overhead to correct more than 14 errors in every 514 bits. It is required for 50G (PAM4) channels and is used across all 800G, 400G, 200G, 100G-CR2, and 50G-CR interfaces. The Reed-Solomon RS-FEC (528,514) algorithm adds 14 bits of coding information to each 514-bit data stream. It replaces and uses the same overhead as the 64B/66B encoding, so the bit rate remains unaffected. This algorithm can correct up to 7 bit errors in each 514-bit data stream. RS-FEC (528,514) is used for 25G (NRZ) channels, including 25G, 50G-CR2, and 100G-SR4/CR4 interfaces. Base-R (also known as FireCode/FC) FEC adds 32 bits per 32 blocks of 64B/66B to correct 11 errors in every 2048 bits. It replaces one bit per block, thus using the same overhead as 64B/66B encoding. It is only used for 25G interfaces. This algorithm has a faster implementation speed compared to RS-FEC, resulting in lower latency. Both RS-FEC and Base-R FEC are implemented in hardware. None/Off: FEC is optional and typically useful on 25G channels, including 100G-SR4/CR4 and 50G-CR2 links. If the cable quality is sufficient to achieve a BER of 10⁻¹² without FEC, there is no need to enable it. 10G/40G links never require FEC. If errors occur on 10G/40G links, replace the faulty cable or module causing the issue. Auto: FEC can be auto-negotiated between two devices. When auto-negotiation is enabled, the default FEC setting is automatic to exchange FEC capability information with the peer. The port’s FEC active/operational status is set according to the negotiation result. Auto is the default setting on NVIDIA switches (auto-negotiation enabled by default). 3.8 CLI Display Examples of QSFPDD-ZR-400G on Cisco Switches n# show version Cisco Nexus Operating System (NX-OS) Software TAC support: http://www.cisco.com/tac Copyright (C) 2002-2023, Cisco and/or its affiliates. All rights reserved. The copyrights to certain works contained in this software are owned by other third parties and used and distributed under their own licenses, such as open source. This software is provided "as is," and unless otherwise stated, there is no warranty, express or implied, including but not limited to warranties of merchantability and fitness for a particular purpose. Certain components of this software are licensed under the GNU General Public License (GPL) version 2.0 or GNU General Public License (GPL) version 3.0 or the GNU Lesser General Public License (LGPL) Version 2.1 or Lesser General Public License (LGPL) Version 2.0. A copy of each such license is available at http://www.opensource.org/licenses/gpl-2.0.php and http://opensource.org/licenses/gpl-3.0.html and http://www.opensource.org/licenses/lgpl-2.1.php and http://www.gnu.org/licenses/old-licenses/library.txt. Software BIOS: version 01.11 NXOS: version 10.4(2) [Feature Release] Host NXOS: version 10.4(2) BIOS compile time: 06/30/2023 NXOS image file is: bootflash:///nxos64-cs.10.4.2.F.bin NXOS compile time: 11/30/2023 12:00:00 [12/14/2023 05:25:50] NXOS boot mode: LXC Hardware cisco Nexus9000 C9332D-GX2B Chassis Intel(R) Xeon(R) CPU D-1633N @ 2.50GHz with 32801496 kB of memory. Processor Board ID FDO26450X3Y Device name: n bootflash: 115805708 kB Kernel uptime is 0 day(s), 0 hour(s), 43 minute(s), 48 second(s) Last reset at 684261 usecs after Thu Mar 6 09:22:25 2025 Reason: Reset due to upgrade System version: 10.4(3) Service: plugin Core Plugin, Ethernet Plugin Active Package(s): n# show inventory NAME: "Chassis", DESCR: "Nexus9000 C9332D-GX2B Chassis" PID: N9K-C9332D-GX2B , VID: V01 , SN: FDO26450X3Y NAME: "Slot 1", DESCR: "32x400G QSFP-DD + 2x10G SFP+ Ethernet Module" PID: N9K-C9332D-GX2B , VID: V01 , SN: FDO26450X3Y NAME: "Slot 27", DESCR: "32x400G QSFP-DD + 2x10G SFP+ Ethernet Module" PID: N9K-C9332D-GX2B , VID: V01 , SN: FDO26450X3Y NAME: "Power Supply 1", DESCR: "Nexus9000 C9332D-GX2B Chassis Power Supply" PID: NXA-PAC-1500W-PI , VID: V01 , SN: POG2646FTDA NAME: "Power Supply 2", DESCR: "Nexus9000 C9332D-GX2B Chassis Power Supply" PID: NXA-PAC-1500W-PI , VID: V01 , SN: POG2646FT6T NAME: "Fan 1", DESCR: "Nexus9000 C9332D-GX2B Chassis Fan Module" PID: NXA-SFAN-35CFM-PI , VID: V01 , SN: N/A NAME: "Fan 2", DESCR: "Nexus9000 C9332D-GX2B Chassis Fan Module" PID: NXA-SFAN-35CFM-PI , VID: V01 , SN: N/A NAME: "Fan 3", DESCR: "Nexus9000 C9332D-GX2B Chassis Fan Module" PID: NXA-SFAN-35CFM-PI , VID: V01 , SN: N/A NAME: "Fan 4", DESCR: "Nexus9000 C9332D-GX2B Chassis Fan Module" PID: NXA-SFAN-35CFM-PI , VID: V01 , SN: N/A NAME: "Fan 5", DESCR: "Nexus9000 C9332D-GX2B Chassis Fan Module" PID: NXA-SFAN-35CFM-PI , VID: V01 , SN: N/A NAME: "Fan 6", DESCR: "Nexus9000 C9332D-GX2B Chassis Fan Module" PID: NXA-SFAN-35CFM-PI , VID: V01 , SN: N/A n# show running-config interface ethernet 1/1 !Command: show running-config interface Ethernet1/1 !Running configuration last done at: Thu Mar 6 09:29:51 2025 !Time: Thu Mar 6 10:10:51 2025 version 10.4(2) Bios:version 01.11 interface Ethernet1/1 zr-optics fec cFEC muxponder 1x400 modulation 16QAM dac-rate 1x1 zr-optics cd-min -2300 cd-max 2300 zr-optics transmit-power -70 zr-optics dwdm-carrier 100MHz-grid frequency 1921000 no shutdown n# show interface status -------------------------------------------------------------------------------- Port Name Status Vlan Duplex Speed Type -------------------------------------------------------------------------------- mgmt0 -- notconnec routed auto auto -- -------------------------------------------------------------------------------- Port Name Status Vlan Duplex Speed Type -------------------------------------------------------------------------------- Eth1/1 -- connected 1 full 400G QSFP-DD-400 G-ZR-S Eth1/2 -- xcvrAbsen 1 auto auto -- Eth1/3/1 -- xcvrAbsen 1 auto auto -- Eth1/3/2 -- xcvrAbsen 1 auto auto -- Eth1/3/3 -- xcvrAbsen 1 auto auto -- Eth1/3/4 -- xcvrAbsen 1 auto auto -- Eth1/4 -- xcvrAbsen 1 auto auto -- Eth1/5/1 -- xcvrAbsen 1 auto auto -- Eth1/5/2 -- xcvrAbsen 1 auto auto -- Eth1/5/3 -- xcvrAbsen 1 auto auto -- Eth1/5/4 -- xcvrAbsen 1 auto auto -- Eth1/6 -- xcvrAbsen 1 auto auto -- Eth1/7/1 -- xcvrAbsen 1 auto auto -- Eth1/7/2 -- xcvrAbsen 1 auto auto -- Eth1/7/3 -- xcvrAbsen 1 auto auto -- Eth1/7/4 -- xcvrAbsen 1 auto auto -- Eth1/8 -- xcvrAbsen 1 auto auto -- Eth1/9/1 -- xcvrAbsen 1 auto auto -- Eth1/9/2 -- xcvrAbsen 1 auto auto -- Eth1/9/3 -- xcvrAbsen 1 auto auto -- Eth1/9/4 -- xcvrAbsen 1 auto auto -- Eth1/10 -- xcvrAbsen 1 auto auto -- Eth1/11/1 -- xcvrAbsen 1 auto auto -- Eth1/11/2 -- xcvrAbsen 1 auto auto -- Eth1/11/3 -- xcvrAbsen 1 auto auto -- Eth1/11/4 -- xcvrAbsen 1 auto auto -- Eth1/12 -- xcvrAbsen 1 auto auto -- Eth1/13 -- xcvrAbsen 1 auto auto -- Eth1/14 -- xcvrAbsen 1 auto auto -- Eth1/15 -- xcvrAbsen 1 auto auto -- Eth1/16 -- xcvrAbsen 1 auto auto -- Eth1/17 -- xcvrAbsen 1 auto auto -- Eth1/18 -- xcvrAbsen 1 auto auto -- Eth1/19 -- xcvrAbsen 1 auto auto -- Eth1/20 -- xcvrAbsen 1 auto 100G -- Eth1/21 -- xcvrAbsen 1 auto auto -- Eth1/22 -- xcvrAbsen 1 auto 100G -- Eth1/23 -- xcvrAbsen 1 auto auto -- Eth1/24 -- xcvrAbsen 1 auto auto -- Eth1/25 -- xcvrAbsen 1 auto auto -- Eth1/26 -- xcvrAbsen 1 auto auto -- Eth1/27 -- xcvrAbsen 1 auto auto -- Eth1/28 -- xcvrAbsen 1 auto auto -- Eth1/29 -- xcvrAbsen 1 auto auto -- Eth1/30 -- xcvrAbsen 1 auto auto -- Eth1/31 -- xcvrAbsen 1 auto auto -- Eth1/32 -- xcvrAbsen 1 auto auto -- Eth1/33 -- xcvrAbsen 1 auto auto -- Eth1/34 -- xcvrAbsen 1 auto auto -- n# show interface ethernet 1/1 transceiver details Ethernet1/1 transceiver is present type is QSFP-DD-400G-ZR-S name is FS part number is QDD-ZR-400G revision is A serial number is A2310220126 nominal bitrate is 425000 MBit/sec per channel cisco id is 24 cisco extended id number is 21 firmware version is 2.11 Link length SMF is 8 km Nominal transmitter wavelength is 1547.70 nm Wavelength tolerance is 0.015 nm host lane count is 8 media lane count is 1 max module temperature is 70 deg C min module temperature is 0 deg C min operational voltage is 3.14 V vendor OUI is 0x7cb25c date code is 240507 clei code is INUIANYEAA power class is 8 (>14 W maximum) max power is 23.75 W near-end lanes used none far-end lane code for 8 lanes Undefined media interface is unknown value 0x10 Advertising code is Optical Interfaces: SMF Host electrical interface code is 400GAUI-8 C2M (Annex 120E) FEC State: FEC cFEC Optics Status Optics Type: QSFP-DD-400G-ZR-S DWDM carrier Info: Frequency: 192.10 THz Alarm Status ------------ DAC Rate: 1x1 THRESHOLD VALUES ---------------- Configured Tx Power: 0 dBm Modulation Type: 16QAM Muxponder Type: 1x400 Configured CD-MIN: -1430864206 ps/nm CD-MAX: 530644985 ps/nm Lane Number:1 Network Lane ---------------------------------------------------------------------------- Current Alarms Warnings Measurement High Low High Low ---------------------------------------------------------------------------- Temperature 65.62 C 75.00 C -5.00 C 70.00 C 0.00 C Voltage 3.30 V 3.60 V 3.00 V 3.46 V 3.13 V Current N/A N/A N/A N/A N/A Tx Power -7.01 dBm 2.99 dBm -8.01 dBm 1.99 dBm -7.01 dBm Rx Power -11.13 dBm 7.99 dBm -23.01 dBm 7.99 dBm -22.21 dBm Transmit Fault Count = 0 ---------------------------------------------------------------------------- Note: ++ high-alarm; + high-warning; -- low-alarm; - low-warning *** This QSFP support partial diagnostic data! *** 4. General Troubleshooting Approach Before addressing specific issues, it is essential to eliminate the impact of physical hardware by applying the control variable method to troubleshoot the physical layer. The physical hardware layer includes devices, fiber jumpers, high-speed modules, and cables. Common physical layer hardware errors：Incorrect DDM parameter readings. Check all DDM parameter indicators carefully. Procedure: First, use relevant commands to obtain the module’s DDM information. Different commands may output different DDM data. Based on the information, preliminarily identify the affected component and proceed with hardware troubleshooting. Follow the principle of simplicity—start troubleshooting from the most accessible or likely components. When diagnosing specific issues, it is recommended to first inspect the end faces of optical modules and fiber jumpers (except for DAC/AOC cables) for contamination or wear. If any such issues are found, clean the end faces before reuse. If a visual fiber inspection tool is not available, perform multiple cleanings to ensure cleanliness. High-speed module or cable issues: Replace with the same type of known-good product for interconnection or testing. Fiber jumper issues: Replace the jumper cable. For long-distance cables in the field, use an OTDR to assess overall cable attenuation. Switch ports or devices: Test by swapping to different ports or devices. Loopback testing: Conduct loopback tests at the near-end or far-end device. This can be a single-port loopback or a loopback between different ports on the same device. 5. FS Typical After-Sales Case Collection 5.1 Incomplete DDM Information Display Bias Current Display Issue of QSFP-DD-ZR-400G Coherent Optical Modules on Cisco Switches Issue Description: On Cisco 400G switches such as the N9K-C9332D-GX2B or other Cisco GX series devices that support coherent modules, the DDM information of coherent modules is incompletely displayed. Some key parameter data, such as the bias current, is missing from the DDM output. Affected Devices: N9K-C9332D-GX2B N9K-C9316D-GX Related Products: QSFPDD-ZR-400G QSFPDD-ZRP-400G QDD-ZRP-400G-HT Log: show interface ethernet 1/1 transceiver details Ethernet1/1 transceiver is present type is QSFP-DD-400G-ZR-S name is FS part number is QDD-ZR-400G revision is A serial number is A2310220126 nominal bitrate is 425000 MBit/sec per channel cisco id is 24 cisco extended id number is 21 firmware version is 2.11 Link length SMF is 8 km Nominal transmitter wavelength is 1547.70 nm Wavelength tolerance is 0.015 nm host lane count is 8 media lane count is 1 max module temperature is 70 deg C min module temperature is 0 deg C min operational voltage is 3.14 V vendor OUI is 0x7cb25c date code is 240507 clei code is INUIANYEAA power class is 8 (>14 W maximum) max power is 23.75 W near-end lanes used none far-end lane code for 8 lanes Undefined media interface is unknown value 0x10 Advertising code is Optical Interfaces: SMF Host electrical interface code is 400GAUI-8 C2M (Annex 120E) FEC State: FEC cFEC Optics Status Optics Type: QSFP-DD-400G-ZR-S DWDM carrier Info: Frequency: 192.10 THz Alarm Status ------------ DAC Rate: 1x1 THRESHOLD VALUES ---------------- Configured Tx Power: 0 dBm Modulation Type: 16QAM Muxponder Type: 1x400 Configured CD-MIN: -1430864206 ps/nm CD-MAX: 530644985 ps/nm Lane Number:1 Network Lane ---------------------------------------------------------------------------- Current Alarms Warnings Measurement High Low High Low ---------------------------------------------------------------------------- Temperature 65.62 C 75.00 C -5.00 C 70.00 C 0.00 C Voltage 3.30 V 3.60 V 3.00 V 3.46 V 3.13 V Current N/A N/A N/A N/A N/A Tx Power -7.01 dBm 2.99 dBm -8.01 dBm 1.99 dBm -7.01 dBm Rx Power -11.13 dBm 7.99 dBm -23.01 dBm 7.99 dBm -22.21 dBm Transmit Fault Count = 0 ---------------------------------------------------------------------------- Note: ++ high-alarm; + high-warning; -- low-alarm; - low-warning *** This QSFP support partial diagnostic data! *** Analysis Approach: Compared with the traditional DML/EML laser module, which directly monitors the laser current through a simple analog circuit, the coherent module usually uses an external cavity laser or an integrated coherent transmitter. Its bias current is precisely controlled by an internal closed-loop circuit, and no external current monitoring interface is designed. Therefore, the bias current information of the module cannot be directly monitored. Solution: Users can disregard the missing bias current warning and instead focus on verifying whether the other key DDM parameters are reporting correctly. 5.2 Link Failure on Specific Devices with High Software Versions QSFP-DD-ZR-400G Coherent Optical Module Fails to Operate on Cisco Switches with Certain High Software Versions Issue Description: During use of the QSFP-DD-ZR-400G series modules on high-speed switches, the optical module temperature rises rapidly. When reaching a certain temperature threshold, this causes port jitter and results in a large number of bit errors during transmission. Affected Devices: N9K-C9332D-GX2B Related Products: QSFPDD-ZR-400G QSFPDD-ZRP-400G QDD-ZRP-400G-HT Log: 在 version 10.2(5)的日志输出： n# show version Cisco Nexus Operating System (NX-OS) Software TAC support: http://www.cisco.com/tac Copyright (C) 2002-2023, Cisco and/or its affiliates. All rights reserved. The copyrights to certain works contained in this software are owned by other third parties and used and distributed under their own licenses, such as open source. This software is provided "as is," and unless otherwise stated, there is no warranty, express or implied, including but not limited to warranties of merchantability and fitness for a particular purpose. Certain components of this software are licensed under the GNU General Public License (GPL) version 2.0 or GNU General Public License (GPL) version 3.0 or the GNU Lesser General Public License (LGPL) Version 2.1 or Lesser General Public License (LGPL) Version 2.0. A copy of each such license is available at http://www.opensource.org/licenses/gpl-2.0.php and http://opensource.org/licenses/gpl-3.0.html and http://www.opensource.org/licenses/lgpl-2.1.php and http://www.gnu.org/licenses/old-licenses/library.txt. Software BIOS: version 01.11 NXOS: version 10.2(5) [Maintenance Release] Host NXOS: version 10.2(5) BIOS compile time: 06/30/2023 NXOS image file is: bootflash:///nxos64-cs.10.2.5.M.bin NXOS compile time: 3/10/2023 12:00:00 [03/03/2023 12:00:11] NXOS boot mode: LXC n# show interface status -------------------------------------------------------------------------------- Port Name Status Vlan Duplex Speed Type -------------------------------------------------------------------------------- mgmt0 -- notconnec routed auto auto -- -------------------------------------------------------------------------------- Port Name Status Vlan Duplex Speed Type -------------------------------------------------------------------------------- Eth1/1 -- xcvrAbsen 1 auto auto -- Eth1/2 -- xcvrAbsen 1 auto auto -- Eth1/3 -- connected 1 auto auto QSFP-DD-400G-ZR Eth1/4 -- xcvrAbsen 1 auto auto -- Eth1/5 -- xcvrAbsen 1 auto auto -- Eth1/6 -- xcvrAbsen 1 auto auto -- Ethernet1/3 transceiver is present type is QSFP-DD-400G-ZR name is FS part number is QDD-ZR-400G revision is 10 serial number is A2310220131 nominal bitrate is 425000 MBit/sec per channel cisco id is 0x18 cisco extended id number is 0 firmware version is 2.11 Link length SMF is 16 km Nominal transmitter wavelength is 1547.70 nm Wavelength tolerance is 0.015 nm host lane count is 8 media lane count is 1 max module temperature is 70 deg C min module temperature is 0 deg C min operational voltage is 3.14 V vendor OUI is 0x000000 date code is 231026 power class is 8 (>14 W maximum) max power is 16.50 W near-end lanes used none far-end lane code for 8 lanes Undefined media interface is unknown value 0x10 Advertising code is Optical Interfaces: SMF Host electrical interface code is 400GAUI-8 C2M (Annex 120E) Lane Number:1 Network Lane ---------------------------------------------------------------------------- Current Alarms Warnings Measurement High Low High Low ---------------------------------------------------------------------------- Temperature 71.50 C + 75.00 C -5.00 C 70.00 C 0.00 C Voltage 3.33 V 3.60 V 3.00 V 3.46 V 3.13 V Current N/A N/A N/A N/A N/A Tx Power -8.99 dBm -4.00 dBm -16.02 dBm -5.00 dBm -15.08 dBm Rx Power -11.01 dBm 3.99 dBm -23.01 dBm 2.99 dBm -22.21 dBm Transmit Fault Count = 0 ---------------------------------------------------------------------------- Note: ++ high-alarm; + high-warning; -- low-alarm; - low-warning 在 version 10.4(2)的日志输出： n# show version Cisco Nexus Operating System (NX-OS) Software TAC support: http://www.cisco.com/tac Copyright (C) 2002-2023, Cisco and/or its affiliates. All rights reserved. The copyrights to certain works contained in this software are owned by other third parties and used and distributed under their own licenses, such as open source. This software is provided "as is," and unless otherwise stated, there is no warranty, express or implied, including but not limited to warranties of merchantability and fitness for a particular purpose. Certain components of this software are licensed under the GNU General Public License (GPL) version 2.0 or GNU General Public License (GPL) version 3.0 or the GNU Lesser General Public License (LGPL) Version 2.1 or Lesser General Public License (LGPL) Version 2.0. A copy of each such license is available at http://www.opensource.org/licenses/gpl-2.0.php and http://opensource.org/licenses/gpl-3.0.html and http://www.opensource.org/licenses/lgpl-2.1.php and http://www.gnu.org/licenses/old-licenses/library.txt. Software BIOS: version 01.11 NXOS: version 10.4(2) [Feature Release] Host NXOS: version 10.4(2) BIOS compile time: 06/30/2023 NXOS image file is: bootflash:///nxos64-cs.10.4.2.F.bin NXOS compile time: 11/30/2023 12:00:00 [12/14/2023 05:25:50] NXOS boot mode: LXC n# show interface status -------------------------------------------------------------------------------- Port Name Status Vlan Duplex Speed Type -------------------------------------------------------------------------------- mgmt0 -- notconnec routed auto auto -- -------------------------------------------------------------------------------- Port Name Status Vlan Duplex Speed Type -------------------------------------------------------------------------------- Eth1/1 -- xcvrAbsen 1 auto auto -- Eth1/2 -- xcvrAbsen 1 auto auto -- Eth1/3 -- notconnec 1 auto auto QSFP-DD-400G-ZR Eth1/4 -- xcvrAbsen 1 auto auto -- Eth1/5 -- xcvrAbsen 1 auto auto -- Eth1/6 -- xcvrAbsen 1 auto auto -- Ethernet1/3 transceiver is present type is QSFP-DD-400G-ZR name is FS part number is QDD-ZR-400G revision is 10 serial number is A2310220131 nominal bitrate is 425000 MBit/sec per channel cisco id is 0x18 cisco extended id number is 0 firmware version is 2.11 Link length SMF is 16 km Nominal transmitter wavelength is 1547.70 nm Wavelength tolerance is 0.015 nm host lane count is 8 media lane count is 1 max module temperature is 70 deg C min module temperature is 0 deg C min operational voltage is 3.14 V vendor OUI is 0x000000 date code is 231026 power class is 8 (>14 W maximum) max power is 16.50 W near-end lanes used none far-end lane code for 8 lanes Undefined media interface is unknown value 0x10 Advertising code is Optical Interfaces: SMF Host electrical interface code is 400GAUI-8 C2M (Annex 120E) Lane Number:1 Network Lane ---------------------------------------------------------------------------- Current Alarms Warnings Measurement High Low High Low ---------------------------------------------------------------------------- Temperature N/A N/A N/A N/A N/A Voltage N/A N/A N/A N/A N/A Current N/A N/A N/A N/A N/A Tx Power N/A N/A N/A N/A N/A Rx Power N/A N/A N/A N/A N/A Transmit Fault Count = 0 Analysis Approach: Version upgrades are usually to fix bugs or security risks in the low version, or to add some functions. For optical modules, after the upgrade, the device's information authentication of the optical module may change. The authentication information in the original optical module EERPOM is no longer recognized by the original switch. It is necessary to upgrade the content in the optical module EEPROM to meet the standard of the upgraded device authentication. Solution: Upgrade the EERPOM information of the optical module. log: n# show version Cisco Nexus Operating System (NX-OS) Software TAC support: http://www.cisco.com/tac Copyright (C) 2002-2023, Cisco and/or its affiliates. All rights reserved. The copyrights to certain works contained in this software are owned by other third parties and used and distributed under their own licenses, such as open source. This software is provided "as is," and unless otherwise stated, there is no warranty, express or implied, including but not limited to warranties of merchantability and fitness for a particular purpose. Certain components of this software are licensed under the GNU General Public License (GPL) version 2.0 or GNU General Public License (GPL) version 3.0 or the GNU Lesser General Public License (LGPL) Version 2.1 or Lesser General Public License (LGPL) Version 2.0. A copy of each such license is available at http://www.opensource.org/licenses/gpl-2.0.php and http://opensource.org/licenses/gpl-3.0.html and http://www.opensource.org/licenses/lgpl-2.1.php and http://www.gnu.org/licenses/old-licenses/library.txt. Software BIOS: version 01.11 NXOS: version 10.4(2) [Feature Release] Host NXOS: version 10.4(2) BIOS compile time: 06/30/2023 NXOS image file is: bootflash:///nxos64-cs.10.4.2.F.bin NXOS compile time: 11/30/2023 12:00:00 [12/14/2023 05:25:50] NXOS boot mode: LXC n# show interface status -------------------------------------------------------------------------------- Port Name Status Vlan Duplex Speed Type -------------------------------------------------------------------------------- mgmt0 -- notconnec routed auto auto -- -------------------------------------------------------------------------------- Port Name Status Vlan Duplex Speed Type -------------------------------------------------------------------------------- Eth1/1 -- xcvrAbsen 1 auto auto -- Eth1/2 -- xcvrAbsen 1 auto auto -- Eth1/3 -- notconnec 1 auto auto QSFP-DD-400G-ZR Eth1/4 -- xcvrAbsen 1 auto auto -- Eth1/5 -- xcvrAbsen 1 auto auto -- Eth1/6 -- xcvrAbsen 1 auto auto -- Ethernet1/3 transceiver is present type is QSFP-DD-400G-ZR name is FS part number is QDD-ZR-400G revision is 10 serial number is A2310220131 nominal bitrate is 425000 MBit/sec per channel cisco id is 0x18 cisco extended id number is 0 firmware version is 2.11 Link length SMF is 16 km Nominal transmitter wavelength is 1547.70 nm Wavelength tolerance is 0.015 nm host lane count is 8 media lane count is 1 max module temperature is 70 deg C min module temperature is 0 deg C min operational voltage is 3.14 V vendor OUI is 0x000000 date code is 231026 power class is 8 (>14 W maximum) max power is 16.50 W near-end lanes used none far-end lane code for 8 lanes Undefined media interface is unknown value 0x10 Advertising code is Optical Interfaces: SMF Host electrical interface code is 400GAUI-8 C2M (Annex 120E) Lane Number:1 Network Lane ---------------------------------------------------------------------------- Current Alarms Warnings Measurement High Low High Low ---------------------------------------------------------------------------- Temperature 64.58 C 75.00 C -5.00 C 70.00 C 0.00 C Voltage 3.31 V 3.60 V 3.00 V 3.46 V 3.13 V Current N/A N/A N/A N/A N/A Tx Power -7.01 dBm 2.99 dBm -8.01 dBm 1.99 dBm -7.01 dBm Rx Power -11.13 dBm 7.99 dBm -23.01 dBm 7.99 dBm -22.21 dBm Transmit Fault Count = 0 ---------------------------------------------------------------------------- Note: ++ high-alarm; + high-warning; -- low-alarm; - low-warning *** This QSFP support partial diagnostic data! *** 5.3 Overheating due to excessive power consumption Issue Description: During operation of the QSFP-DD-ZR-400G series modules on high-speed switches, the optical module temperature rises rapidly. When the temperature reaches a certain threshold, it causes port jitter and results in a significant increase in bit errors during transmission. Affected Devices: N9K-C9316D-GX Arista 7280DR3K-24 Dell Z9332F-ON Related Products: QSFPDD-ZR-400G QSFPDD-ZRP-400G QDD-ZRP-400G-HT Log: localhost#show interfaces ethernet 22/1 transceiver detail mA: milliamperes, dBm: decibels (milliwatts), NA or N/A: not applicable. A2D readouts (if they differ), are reported in parentheses. The threshold values are calibrated. High Alarm High Warn Low Alarm Low Warn Temperature Threshold Threshold Threshold Threshold Port (Celsius) (Celsius) (Celsius) (Celsius) (Celsius) ------- ------------ ---------- ---------- ---------- ---------- Et22/1 65.95 75.00 70.00 -5.00 0.00 High Alarm High Warn Low Alarm Low Warn Voltage Threshold Threshold Threshold Threshold Port (Volts) (Volts) (Volts) (Volts) (Volts) ------- ------------ ---------- ---------- ---------- ---------- Et22/1 3.31 3.60 3.47 3.00 3.14 High Alarm High Warn Low Alarm Low Warn Current Threshold Threshold Threshold Threshold Port (mA) (mA) (mA) (mA) (mA) ------- ------------ ---------- ---------- ---------- ---------- Et22/1 100.00 120.00 110.00 80.00 90.00 High Alarm High Warn Low Alarm Low Warn Tx Power Threshold Threshold Threshold Threshold Port (dBm) (dBm) (dBm) (dBm) (dBm) ------- ------------ ---------- ---------- ---------- ---------- Et22/1 -8.99 -4.00 -5.00 -16.00 -15.00 High Alarm High Warn Low Alarm Low Warn Rx Power Threshold Threshold Threshold Threshold Port (dBm) (dBm) (dBm) (dBm) (dBm) ------- ------------ ---------- ---------- ---------- ---------- Et22/1 -8.95 4.00 3.00 -23.01 -22.01 Analysis Approach: Typical Power Consumption Comparison of 400G Coherent Optical Modules Product Type QSFPDD-ZR-400G QSFPDD-ZRP-400G QDD-ZRP-400G-HT Power Consumption 18W 22.5W 22.5W Due to the unique DSP chips, highly integrated silicon photonics components, and tunable lasers, 400G coherent optical modules typically have relatively high overall power consumption (≥18W), generating significant heat during operation. In contrast, data center 400G QSFP-DD switch ports are generally designed to support conventional QSFP-DD 400G modules (such as QDD-SR8-400G, QDD-DR4-400G, QDD-LR4-400G), which usually consume between 8W and 12W—much lower than QDD-ZR-400G coherent modules. If the device’s cooling capability is insufficient or the ambient environment has limited heat dissipation, the temperature of the coherent module will rise rapidly during operation. Optical modules are temperature-sensitive devices, and especially under high-temperature conditions, rapid temperature increases degrade module performance and shorten device lifespan. If the rising heat is not effectively mitigated, the resulting performance degradation of the module and the overall device will lead to an increase in port error counts, causing port jitter and ultimately resulting in complete loss of port connectivity. Solution: If the module’s operating temperature remains within the allowable threshold range and is about 10°C below the high-temperature alarm threshold, there is no cause for concern. This temperature rise is a normal characteristic of high-power modules during operation. However, if the module’s temperature approaches the high alarm threshold or critical limit, cooling measures should be taken. Common steps include: Reclean the end faces of the optical module and fiber jumpers to ensure they are clean and free from wear. If the device supports adjustable fan speeds, increase the fan speed level to enhance cooling capacity. Enable a higher power budget for the port if supported by the device. Use external cooling solutions such as air conditioning or exhaust fans. Depending on actual business requirements, consider reducing the optical module density on ports to decrease device load. 5.4 Function configuration error 5.4.1 FEC mismatch cannot be connected Issue Description: When using the QSFP-DD-ZR-400G series modules on different high-speed switches, devices fail to interoperate properly due to mismatched FEC types. Affected Devices: N9K-C9316D-GX N9K-C9332D-GX2B Arista 7280DR3K-24 Dell Z9332F-ON Juniper 5220-32CD Related Products: QSFPDD-ZR-400G QSFPDD-ZRP-400G QDD-ZRP-400G-HT Log: Cisco N9K-C9332D-GX2B设备FEC类型为unknown n# show interface ethernet 1/13 transceiver details Ethernet1/13 transceiver is present type is QSFP-DD-400G-ZR name is FS part number is QDD-ZR-400G revision is 10 serial number is A2310220131 nominal bitrate is 425000 MBit/sec per channel cisco id is 0x18 cisco extended id number is 0 firmware version is 2.11 Link length SMF is 16 km Nominal transmitter wavelength is 1547.70 nm Wavelength tolerance is 0.015 nm host lane count is 8 media lane count is 1 max module temperature is 70 deg C min module temperature is 0 deg C min operational voltage is 3.14 V vendor OUI is 0x000000 date code is 231026 power class is 8 (>14 W maximum) max power is 16.50 W near-end lanes used none far-end lane code for 8 lanes Undefined media interface is unknown value 0x10 Advertising code is Optical Interfaces: SMF Host electrical interface code is 400GAUI-8 C2M (Annex 120E) FEC State: FEC unknown Optics Status Optics Type: QSFP-DD-400G-ZR-S DWDM carrier Info: Frequency: 0.00 THz Lane Number:1 Network Lane ---------------------------------------------------------------------------- Current Alarms Warnings Measurement High Low High Low ---------------------------------------------------------------------------- Temperature 71.50 C + 75.00 C -5.00 C 70.00 C 0.00 C Voltage 3.33 V 3.60 V 3.00 V 3.46 V 3.13 V Current 100.00 mA 120.00 mA 80.00 mA 110.00 mA 90.00 mA Tx Power -8.99 dBm -4.00 dBm -16.02 dBm -5.00 dBm -15.08 dBm Rx Power N/A 3.99 dBm -23.01 dBm 2.99 dBm -22.21 dBm Transmit Fault Count = 0 ---------------------------------------------------------------------------- Note: ++ high-alarm; + high-warning; -- low-alarm; - low-warning Arista 7280DR3K-24配置为C-FEC localhost#show interfaces ethernet 22/1 status Port Name Status Vlan Duplex Speed Type Flags Encapsulation Et22/1 connected 1 full 400G 400GBASE-ZR localhost# localhost# localhost#show interfaces ethernet 22/1 hardware * = Requires speed group setting change Ethernet22/1 Model: DCS-7280DR3K-24 Type: 400GBASE-ZR Speed/duplex: 400G-8/full(default) Flowcontrol: rx-(off,on),tx-(off) Modulation: 16QAM Error correction: C-FEC(16QAM(default)) localhost# localhost# localhost#show interfaces ethernet 22/1 transceiver hardware Name: Ethernet22/1 Media type: 400GBASE-ZR Module presence: detected Maximum module power (W): 16.5 Maximum slot power (W): 20.0 Analysis Approach: To ensure reliable data transmission, 400G coherent modules require FEC (Forward Error Correction) to be enabled on the host ports. When devices are interconnected, the FEC types must be consistent between both ends. Different QSFP-DD-ZR-400G modules support different FEC types, as detailed below: Product Type QSFPDD-ZR-400G QSFPDD-ZRP-400G QDD-ZRP-400G-HT FEC Type CFEC CFEC/OFEC CFEC/OFEC For example, on Cisco devices, the host port may have no FEC type configured, while on Arista switches, CFEC is configured. This mismatch in FEC types causes interoperability issues, preventing successful link establishment. Solution: Enable the CFEC configuration on the Cisco N9K-C9332D-GX2B switch as follows: n(config)# interface ethernet 1/13 n(config-if)# zr-optics fec cFEC muxponder 1x400 modulation 16QAM dac-rate 1x1 n(config-if)# no shutdown Log: n# show interface ethernet 1/1 transceiver details Ethernet1/1 transceiver is present type is QSFP-DD-400G-ZR-S name is FS part number is QDD-ZR-400G revision is A serial number is A2310220126 nominal bitrate is 425000 MBit/sec per channel cisco id is 24 cisco extended id number is 21 firmware version is 2.11 Link length SMF is 8 km Nominal transmitter wavelength is 1547.70 nm Wavelength tolerance is 0.015 nm host lane count is 8 media lane count is 1 max module temperature is 70 deg C min module temperature is 0 deg C min operational voltage is 3.14 V vendor OUI is 0x7cb25c date code is 240507 clei code is INUIANYEAA power class is 8 (>14 W maximum) max power is 23.75 W near-end lanes used none far-end lane code for 8 lanes Undefined media interface is unknown value 0x10 Advertising code is Optical Interfaces: SMF Host electrical interface code is 400GAUI-8 C2M (Annex 120E) FEC State: FEC cFEC Optics Status Optics Type: QSFP-DD-400G-ZR-S DWDM carrier Info: Frequency: 192.10 THz Alarm Status ------------ DAC Rate: 1x1 THRESHOLD VALUES ---------------- Configured Tx Power: 0 dBm Modulation Type: 16QAM Muxponder Type: 1x400 Configured CD-MIN: -1430864206 ps/nm CD-MAX: 530644985 ps/nm 5.4.2 Coherent module channel configuration error Issue Description: When a 400G coherent optical module is installed on an Arista 400G switch, the switch’s CLI reports a configuration error, the port fails to establish a link, and the DDM information shows no transmit or receive optical power. Affected Devices: Arista DSA7280CR3K-36A-F Arista 7280CR3K-32D4A Related Products: QSFPDD-ZR-400G QSFPDD-ZRP-400G QDD-ZRP-400G-HT Log: %TRANSCEIVER-4-FREQUENCY_MISCONFIGURED: Transceiver for interface Ethernet36 has an unconfigured or misconfigured frequency or channel. PN-TX-Peer-RTR1#show interfaces Ethernet36/1 transceiver detail mA: milliamperes, dBm: decibels (milliwatts), NA or N/A: not applicable. A2D readouts (if they differ), are reported in parentheses. The threshold values are calibrated. High Alarm High Warn Low Alarm Low Warn Temperature Threshold Threshold Threshold Threshold Port (Celsius) (Celsius) (Celsius) (Celsius) (Celsius) ------- ------------ ---------- ---------- ---------- ---------- Et36/1 23.27 75.00 70.00 -5.00 0.00 High Alarm High Warn Low Alarm Low Warn Voltage Threshold Threshold Threshold Threshold Port (Volts) (Volts) (Volts) (Volts) (Volts) ------- ------------ ---------- ---------- ---------- ---------- Et36/1 3.31 3.60 3.47 3.00 3.14 High Alarm High Warn Low Alarm Low Warn Current Threshold Threshold Threshold Threshold Port (mA) (mA) (mA) (mA) (mA) ------- ------------ ---------- ---------- ---------- ---------- Et36/1 0.00 120.00 110.00 80.00 90.00 High Alarm High Warn Low Alarm Low Warn Tx Power Threshold Threshold Threshold Threshold Port (dBm) (dBm) (dBm) (dBm) (dBm) ------- ------------ ---------- ---------- ---------- ---------- Et36/1 -30.00 -4.00 -5.00 -16.00 -15.00 High Alarm High Warn Low Alarm Low Warn Rx Power Threshold Threshold Threshold Threshold Port (dBm) (dBm) (dBm) (dBm) (dBm) ------- ------------ ---------- ---------- ---------- ---------- Et36/1 -30.00 4.00 3.00 -23.01 -22.01 Analysis Approach: The device log reports that the module on a specific port is unable to provide channel information because an incorrect frequency or channel configuration has been detected or set. As a result, the device cannot operate normally. The error message is explicit, so simply follow the device’s instructions to correctly configure the channel or frequency. Solution: Configure specific frequencies: localhost#configure localhost(config)#interface ethernet 1/1 localhost(config-if-Et1/1)#transceiver frequency 196100 localhost(config-if-Et1/1)#exit localhost(config)#write Copy completed successfully. localhost(config)# The problem was solved after the frequency was configured. 5.5 High-speed product compatibility after-sales service 5.5.1 Arista Compatibility Failure Issue Description: When a 400G coherent optical module is installed on an Arista 400G switch, the switch CLI reports a non-Arista product error, causing the switch port to enter an errdisable state and the port LED to show an amber orange light. Affected Devices: Arista 7280DR3K-24 Related Products: QSFPDD-ZR-400G QSFPDD-ZRP-400G QDD-ZRP-400G-HT Log: Jun 14 06:54:23 localhost XcvrAgent: %TRANSCEIVER-3-DISABLED: The transceiver for interface Ethernet4 has been disabled because it is not qualified. (manufacturer FS model OSFP-800G-SR8 serial number C202405162201) Analysis Approach: Arista devices require that installed products have EEPROM information compliant with Arista’s official certification. Using non-certified products will trigger compatibility error alarms and prevent the product from functioning properly. Solution: Use genuine Arista products or those officially certified by Arista. Modify the module’s EEPROM information to match Arista-supported and certified values. 5.5.2 Juniper compatibility failure Issue Description: When a 400G coherent optical module is inserted into a Juniper 400G switch, the switch fails to display the port’s part number and shows a compatibility warning “NON-JUPR,” unable to recognize the product’s Type field. In most cases, the port can still link and the LED remains green. Affected Devices: Juniper 5220-32CD Related Products: QSFPDD-ZR-400G QSFPDD-ZRP-400G QDD-ZRP-400G-HT Log: root@re0> show chassis hardware Hardware inventory: Item Version Part number Serial number Description Chassis XC0220080002 QFX5220-32CD PSM 0 REV 04 740-085431 1ED79400082 JPSU-1600W-AC-AFO Routing Engine 0 BUILTIN BUILTIN RE-QFX5220-32CD CB 0 REV 07 650-086244 XC0220080002 QFX5220-32CD FPC 0 BUILTIN BUILTIN QFX5220-32CD PIC 0 BUILTIN BUILTIN 32X400G-QSFP-DD Xcvr 24 xxxx NON-JNPR A2310220126 UNKNOWN Fan Tray 0 QFX5220-32CD Fan Tray, Front to Back Airflow - AFO Fan Tray 1 QFX5220-32CD Fan Tray, Front to Back Airflow - AFO Fan Tray 2 QFX5220-32CD Fan Tray, Front to Back Airflow - AFO Fan Tray 3 QFX5220-32CD Fan Tray, Front to Back Airflow - AFO Fan Tray 4 QFX5220-32CD Fan Tray, Front to Back Airflow - AFO Fan Tray 5 QFX5220-32CD Fan Tray, Front to Back Airflow - AFO Analysis Approach: Juniper devices require that installed products have EEPROM information compliant with Juniper’s official certification. If non-certified products are used, a compatibility error warning will be triggered, and the part number will not be displayed. However, in most cases, some information can still be recognized, and the port can usually establish a link. Solution: Use genuine Juniper products or those officially certified by Juniper. Modify the module’s EEPROM information to match the values supported and certified by Juniper. 5.5.3 Dell compatibility failure When the 400G coherent optical module is inserted into the Dell 400G switch, the device interface will report an uncertified error as soon as it is inserted into the port of the device. Output the port media information, and the port shows false. Affected Devices: Dell Z9332F-ON Related Products: QSFPDD-ZR-400G QSFPDD-ZRP-400G QDD-ZRP-400G-HT Log: <165>1 2022-03-30T17:10:12.365074+00:00 0S10 dn_alm 1020 Node. 1-Unit. 1:PRI [event], Dell EMC (OS10) %EQM_MEDIA_PRESENT: Media inserted Media QSFP56-DD 400GBASE-ZR in sllot:1 port:1 serial number:C202405162201 is not qualified OS10# show inventory media System Inventory Media Node/Slot/Port Form-Factor Media Serial-Number Qualified 1/1/1 QSFP56-DD 400GBASE-ZR C202405162201 false 1/1/2 Not Present 1/1/3 Not Present 1/1/4 QSFP56-DD 400GBASE-SR8 CS29000000005 true Analysis Approach: When a 400G coherent optical module is inserted into a Dell 400G switch, a non-certified product error is immediately reported on the port interface. When checking the port's media information, the media status is displayed as "false." Dell devices require that the EEPROM information of the installed module complies with Dell’s official certification. If a non-certified product is used, a compatibility error warning will appear. However, in most cases, as long as the product conforms to standard protocols, some module information can still be recognized, and the port is typically able to establish a link. Solution: Use genuine Dell products or those officially certified by Dell. Modify the module’s EEPROM information to match the values supported and certified by Dell.

Cisco N9K-C9332D-GX2B Configuration Guide

Jun 30, 2025 - Cisco N9K-C9332D-GX2B Configuration Guide Pre-Configuration Preparation 1.1 Hardware Compatibility Check Optical Module Selection: Ensure that the 400G optical module uses a QSFP-DD form factor compatible with the switch port. Coherent applications: For long-haul transmission (typically ≥80 km), select single-mode QSFP-DD modules with duplex LC connectors. Multimode applications: For short-reach scenarios such as intra–data center connections, prioritize 400G SR8 modules with MPO-16 connectors (16-fiber multimode). Single-mode applications: For longer-reach scenarios such as inter–data hall links, use 400G XDR4 (MPO-16 connector, single-mode fiber, up to 2 km) or 400G LR4 (duplex LC connector). High-Speed Cable Selection: DAC (Direct Attach Copper): Suitable for short-reach connections within the same rack (≤3 meters); ensure both ends support 400G line rate. AOC (Active Optical Cable): Offers better EMI resistance; suitable for medium-reach connections (≤100 meters). 1.2 Software Environment Check Check whether the switch system version supports 400G port splitting, FEC error correction, and CMIS 4.0 protocol. The version should be NX-OS 10.4(1) or higher. Port Speed Configuration 2.1 Entering Interface Configuration Mode n# configure terminal Enter configuration commands, one per line. End with CNTL/Z. n(config)# interface ethernet 1/18 n(config-if)# speed ? 10 10Mb/s 100 100Mb/s 1000 1Gb/s 10000 10Gb/s 100000 100Gb/s 200000 200Gb/s 2500 2.5Gb/s 25000 25Gb/s 40000 40Gb/s 400000 400Gb/s 5000 5Gb/s 50000 50Gb/s 800000 800Gb/s auto Auto negotiate speed n(config-if)# speed 400000 2.2 Configure Interface Speed n(config)# interface ethernet 1/18 n(config-if)# speed auto n(config-if)# FEC Configuration n(config)# configure terminal n(config)# interface ethernet 1/18 n(config-if)# fec ? auto FEC auto fc-fec CL74(25/50G) off Turn FEC off rs-cons16 RS FEC Consortium 1.6 (25G) rs-fec CL91(100G) or Consortium 1.5 (25/50G) rs-ieee RS FEC IEEE (25G) n(config-if)# fec auto Wavelength Alignment Configuration 4.1 Enter Port Configuration Mode n# configure terminal Enter configuration commands, one per line. End with CNTL/Z. n(config)# interface ethernet 1/18 n(config-if)# zr-optics ? cd-min Cd-min input dwdm-carrier Dwdm-carrier input mode fec Fec input transmit-power Optics transmit-power 4.2 Set the Target Wavelength n(config-if)# zr-optics dwdm-carrier ? 100GHz-grid Optics dwdm carrier mode 100GHz 100MHz-grid Optics dwdm carrier mode 100MHz 50GHz-grid Optics dwdm carrier mode 50GHz n(config-if)# zr-optics dwdm-carrier 100GHz-grid ? frequency Frequency 100GHz input n(config-if)# zr-optics dwdm-carrier 100GHz-grid frequency ? <19130-19610> Optics frequency 100GHz value n(config-if)# zr-optics dwdm-carrier 100GHz-grid frequency 19130 Error: configure mandatory params first: fec,muxponder,modulation,dac-rate (Need to configure n(config-if)# zr-optics fec... first) n(config-if)# zr-optics dwdm-carrier 100GHz-grid frequency 19130 n(config-if)# commit Command supported only in dual-stage mode 4.3 Save and Verify the Configuration n# show interface ethernet1/18 transceiver details | include wavelength Nominal transmitter wavelength is 1547.70 nm OSNR Threshold Configuration Unable to set Configuration Verification 6.1 Port Status Check # show interface status Port Name Status Vlan Duplex Speed Type mgmt0 -- notconnec routed auto auto -- Port Name Status Vlan Duplex Speed Type Eth1/1 -- xcvrAbsen 1 car car -- Eth1/2 -- xcvrAbsen 1 car car -- Eth1/3 -- xcvrAbsen 1 car car -- Eth1/4 -- xcvrAbsen 1 car car -- Eth1/5 -- xcvrAbsen 1 car car -- Eth1/6 -- xcvrAbsen 1 car -- Eth1/7 -- xcvrAbsen 1 car car -- Eth1/8 -- xcvrAbsen 1 car car -- Eth1/9 -- xcvrAbsen 1 car -- Eth1/10 -- xcvrAbsen 1 car -- Eth1/11 -- xcvrAbsen 1 car -- Eth1/12 -- xcvrAbsen 1 car -- Eth1/13 -- xcvrAbsen 1 auto 400G -- Eth1/14 -- xcvrAbsen 1 auto 400G -- Eth1/15 -- xcvrAbsen 1 auto 400G -- Eth1/16 -- xcvrAbsen 1 auto 400G -- Eth1/17 -- xcvrAbsen 1 auto 400G -- Eth1/18 -- notconnec 1 auto auto QSFP-DD-400G-ZR-S Eth1/19 -- xcvrAbsen 1 auto 400G -- Eth1/20 -- xcvrAbsen 1 auto 400G -- Eth1/21 -- xcvrAbsen 1 auto 400G -- Eth1/22 -- xcvrAbsen 1 auto 100G -- Eth1/23 -- xcvrAbsen 1 car -- Eth1/24 -- xcvrAbsen 1 car -- Eth1/25 -- xcvrAbsen 1 car -- Eth1/26 -- xcvrAbsen 1 car -- Eth1/27 -- xcvrAbsen 1 car -- Eth1/28 -- xcvrAbsen 1 car -- Eth1/29 -- xcvrAbsen 1 car -- Eth1/30 -- xcvrAbsen 1 car -- Eth1/31 -- xcvrAbsen 1 car -- Eth1/32 -- xcvrAbsen 1 car -- Eth1/33 -- xcvrAbsen 1 car -- Eth1/34 -- xcvrAbsen 1 car -- 6.2 FEC Status Verification View FEC configuration: n(config)# show interface ethernet 1/18 Ethernet1/18 is up admin state is up, Dedicated Interface Hardware: 10000/25000/40000/50000/100000/200000/400000 Ethernet, address: 5049 .219b.6594 (bia 5049.219b.6594) MTU 1500 bytes, BW 400000000 Kbit , DLY 10 usec reliability 255/255, txload 1/255, rxload 1/255 Encapsulation ARPA, medium is broadcast Port mode is access full-duplex, 400 Gb/s, media type is 400G Beacon is turned off Auto-Negotiation is turned off FEC mode is Auto Input flow-control is off, output flow-control is off Auto-mdix is turned off Rate mode is dedicated Switchport monitor is off EtherType is 0x8100 EEE (efficient-ethernet) : n/a admin fec state is auto, oper fec state is Kp-fec Last link flapped 00:18:29 Last clearing of "show interface" counters never 3 interface resets Load-Interval #1: 30 seconds 30 seconds input rate 16 bits/sec, 0 packets/sec 30 seconds output rate 16 bits/sec, 0 packets/sec input rate 16 bps, 0 pps; output rate 16 bps, 0 pps Load-Interval #2: 5 minute (300 seconds) 300 seconds input rate 56 bits/sec, 0 packets/sec 300 seconds output rate 56 bits/sec, 0 packets/sec input rate 56 bps, 0 pps; output rate 56 bps, 0 pps RX 0 unicast packets 89 multicast packets 0 broadcast packets 93 input packets 11984 bytes 0 jumbo packets 0 storm suppression bytes 0 runts 0 giants 0 CRC 0 no buffer 0 input error 0 short frame 0 overrun 0 underrun 0 ignored 0 watchdog 0 bad etype drop 0 bad proto drop 0 if down drop 0 input with dribble 0 input discard 0 Rx pause 0 Stomped CRC TX 0 unicast packets 89 multicast packets 0 broadcast packets 93 output packets 11984 bytes 0 jumbo packets 0 output error 0 collision 0 deferred 0 late collision 0 lost carrier 0 no carrier 0 babble 0 output discard 0 Tx pause 6.3 DDM Information View basic information of optical module: n(config)# show interface ethernet 1/18 transceiver Ethernet1/18 transceiver is present type is QSFP-DD-400G-ZR-S name is CISCO-ACACIA part number is DP04QSDD-E30-190 revision is A serial number is ACA281900BX nominal bitrate is 425000 MBit/sec per channel cisco id is 24 cisco extended id number is 21 firmware version is 2.11 Link length SMF is 8 km Nominal transmitter wavelength is 1547.70 nm Wavelength tolerance is 0.015 nm host lane count is 8 media lane count is 1 max module temperature is 70 deg C min module temperature is 0 deg C min operational voltage is 3.14 V vendor OUI is 0x7cb25c date code is 240507 clei code is INUIANYEAA power class is 8 (>14 W maximum) max power is 23.75 W near-end lanes used none far-end lane code for 8 lanes Undefined media interface is unknown value 0x10 Advertising code is Optical Interfaces: SMF Host electrical interface code is 400GAUI-8 C2M (Annex 120E) n(config)# show interface ethernet 1/18 transceiver sprom Ethernet1/18 transceiver is present type is QSFP-DD-400G-ZR-S name is CISCO-ACACIA part number is DP04QSDD-E30-190 revision is A serial number is ACA281900BX nominal bitrate is 425000 MBit/sec per channel cisco id is 24 cisco extended id number is 21 firmware version is 2.11 Link length SMF is 8 km Nominal transmitter wavelength is 1547.70 nm Wavelength tolerance is 0.015 nm host lane count is 8 media lane count is 1 max module temperature is 70 deg C min module temperature is 0 deg C min operational voltage is 3.14 V vendor OUI is 0x7cb25c date code is 240507 clei code is INUIANYEAA power class is 8 (>14 W maximum) max power is 23.75 W near-end lanes used none far-end lane code for 8 lanes Undefined media interface is unknown value 0x10 Advertising code is Optical Interfaces: SMF Host electrical interface code is 400GAUI-8 C2M (Annex 120E) Identifier : 0x18 (QSFP-DD) Connector : 0x07 (LC) Vendor Name : CISCO-ACACIA Vendor OUI : 0x7cb25c Vendor Part No : DP04QSDD-E30-190 Vendor Revision : A Vendor Serial No : ACA281900BX Date Code : 240507 Real-time monitoring of DDM diagnostic data : n(config)# show interface ethernet 1/18 transceiver details Ethernet1/18 transceiver is present type is QSFP-DD-400G-ZR-S name is CISCO-ACACIA part number is DP04QSDD-E30-190 revision is A serial number is ACA281900BX nominal bitrate is 425000 MBit/sec per channel cisco id is 24 cisco extended id number is 21 firmware version is 2.11 Link length SMF is 8 km Nominal transmitter wavelength is 1547.70 nm Wavelength tolerance is 0.015 nm host lane count is 8 media lane count is 1 max module temperature is 70 deg C min module temperature is 0 deg C min operational voltage is 3.14 V vendor OUI is 0x7cb25c date code is 240507 clei code is INUIANYEAA power class is 8 (>14 W maximum) max power is 23.75 W near-end lanes used none far-end lane code for 8 lanes Undefined media interface is unknown value 0x10 Advertising code is Optical Interfaces: SMF Host electrical interface code is 400GAUI-8 C2M (Annex 120E) FEC State: FEC cFEC Optics Status Optics Type: QSFP-DD-400G-ZR-S DWDM carrier Info: Frequency: 193.70 THz Alarm Status ------------ DAC Rate: 1x1 THRESHOLD VALUES ---------------- Configured Tx Power: 0 dBm Modulation Type: 16QAM Muxponder Type: 1x400 Configured CD-MIN: -1430864206 ps/nm CD-MAX: 530644985 ps/nm Lane Number:1 Network Lane ---------------------------------------------------------------------------- Current Alarms Warnings Measurement High Low High Low ---------------------------------------------------------------------------- Temperature 64.38 C 75.00 C -5.00 C 70.00 C 0.00 C Voltage 3.31 V 3.60 V 3.00 V 3.46 V 3.13 V Current N/A N/A N/A N/A N/A Tx Power N/A N/A N/A N/A N/A Rx Power N/A 7.99 dBm -23.01 dBm 7.99 dBm -22.21 dBm Transmit Fault Count = 0 ---------------------------------------------------------------------------- Note: ++ high-alarm; + high-warning; -- low-alarm; - low-warning *** This QSFP support partial diagnostic data! ***