| 1 | Equipment Compatibility | Confirm the host device supports the selected transceiver type, operating temperature range, power budget, and module identification requirements. | Switches Routers Servers Storage Systems | Module is physically accepted but not recognized or disabled by the host. | Review the host equipment documentation and confirm supported module families, electrical requirements, and software or firmware limitations. |
| 2 | Protocol Compatibility | Match the transceiver with the network protocol and signaling standard required by the application. | Ethernet Fibre Channel SONET/SDH Common Data Rates | The module may use a similar connector but cannot establish a link because the protocol or encoding is different. | Check the protocol name, nominal line rate, lane configuration, and host-port operating mode before purchase. |
| 3 | Form Factor | Ensure the physical module size and interface type match the equipment cage. | SFP SFP+ SFP28 QSFP+ QSFP28 QSFP56 QSFP-DD | A module cannot be inserted, or a mechanically compatible module exceeds the port's electrical capability. | Compare the cage type, port designation, lane count, and supported backward-compatibility rules. Mechanical fit alone is not sufficient. |
| 4 | Fiber and Connector Type | Match the transceiver to the installed fiber category, connector, wavelength, and link architecture. | Single-Mode Fiber Multimode Fiber Duplex LC MPO/MTP Copper RJ45 | The link remains down because the connector, fiber type, polarity, or optical mode is incorrect. | Verify connector geometry, fiber type, polarity, wavelength, and whether the installation uses duplex or parallel optics. |
| 5 | Distance and Optical Budget | Choose a transmission distance that covers the actual cable route while staying within the transmitter and receiver power limits. | Short-Reach: up to about 100 m Campus Links: several hundred meters Long-Reach: several kilometers | Insufficient optical power, excessive attenuation, or receiver overload causes unstable or failed communication. | Calculate cable loss, connector loss, splice loss, and any patch-panel allowance. Compare the result with the module's published optical budget. |
| 6 | Speed and Breakout Support | Confirm the required port speed, lane speed, auto-negotiation behavior, and whether breakout operation is supported. | 1 Gb/s 10 Gb/s 25 Gb/s 40 Gb/s 100 Gb/s 200 Gb/s+ | The module operates at a different rate, uses an unsupported lane mode, or cannot divide into the required lower-speed links. | Check port configuration tables, lane mapping, supported breakout cables, and whether speed changes require manual configuration. |
| 7 | Environment, Power, and Monitoring | Evaluate operating temperature, power consumption, diagnostic monitoring, and installation conditions. | Commercial Temperature Industrial Temperature Digital Diagnostics Low-Power Designs | Excessive heat, inadequate cooling, high power draw, or missing diagnostics reduces reliability and service visibility. | Compare temperature ratings with the enclosure environment, verify cage airflow, review maximum power draw, and confirm monitoring support such as optical power and temperature readings. |