| Optical standard and reach | For example, 10GBASE-LR is commonly specified for single-mode fiber links up to 10 km. | For example, 10GBASE-ER is commonly specified for single-mode fiber links up to 40 km. | Confirm the exact Ethernet rate, optical standard, fiber type, connector, and reach in the module datasheet. Reach depends on the complete link, not the module alone. | 15% |
| Wavelength and fiber compatibility | 10GBASE-LR commonly operates around 1310 nm over single-mode fiber. | 10GBASE-ER commonly operates around 1550 nm over single-mode fiber. | Check transmit and receive wavelengths, fiber type, connector polish, and any wavelength-specific restrictions. Match both ends of the link. | 10% |
| Optical power budget | Review transmitter output, receiver sensitivity, and link loss against the intended 10 km route. | Review the specified optical budget and account for fiber attenuation, connectors, splices, and engineering margin. | Request minimum and maximum transmit power, receiver sensitivity, overload level, and the calculation or assumptions used for the link budget. Verify values against the applicable standard and product specification. | 15% |
| Dispersion and link engineering | Confirm that the selected standard and module support the planned fiber and data rate. | At 40 km, chromatic dispersion and other link impairments may be more significant; verify that the specified module is designed for the required reach and rate. | Ask for the supported reach conditions and any limits on fiber, optical loss, or dispersion. Validate the complete path rather than relying only on a distance label. | 10% |
| Compatibility and host interface | Check the required SFP or SFP+ form factor, data rate, and host-device support. | Check the same host requirements and ensure the longer-reach optic is supported by the intended port and platform. | Request a compatibility list or sample qualification plan for the specific host equipment. Confirm EEPROM identification, digital diagnostics support, and any platform restrictions. | 10% |
| Testing and production quality | Test optical output, receiver performance, function, and link stability at the specified rate. | Include checks appropriate to the longer-reach specification, such as optical performance limits and error-free operation under defined test conditions. | Request a sample test report, test limits, equipment calibration records, lot traceability, and a description of production screening. Confirm that test conditions match the product datasheet. | 15% |
| Digital diagnostics and monitoring | Where supported, check readings for temperature, supply voltage, transmit bias, and optical power. | Check the same diagnostic functions and verify that readings remain within the stated operating limits. | Confirm which digital diagnostic monitoring (DDM/DOM) parameters are implemented, their accuracy limits, and how alarms or warning thresholds are reported. | 5% |
| Environmental and compliance documentation | Verify specified operating temperature range and applicable product documentation. | Verify the same requirements and confirm that the module’s rated conditions suit the deployment environment. | Request the datasheet, operating-temperature range, safety and regulatory declarations relevant to the shipment, and any applicable reliability or environmental test information. | 5% |
| Warranty and failure handling | Assess the warranty terms and process for diagnosing or replacing a failed unit. | Confirm that the same support process covers long-reach modules and provides a way to investigate link-budget or interoperability issues. | Review warranty duration, return authorization steps, failure-analysis process, replacement terms, and the information required for a support case. | 5% |
| Technical support and delivery readiness | Evaluate response quality for compatibility checks, sample testing, and deployment questions. | Evaluate whether support can help review the 40 km link budget and troubleshoot end-to-end performance. | Ask for a named technical contact or support channel, expected response times, sample availability, production lead-time confirmation, and change-notification practices. | 10% |