This guide provides a systematic selection process to help you choose the right QSFP28 module every time. You will learn how to verify form factor compatibility, match fiber and distance requirements, validate switch compatibility, consider thermal constraints, and avoid. Marcus examined the six QSFP28 LR4 modules arranged on his workbench. He had processed $12,000 worth of RMA'd optics in just two weeks. His 100G spine links kept dropping with CRC errors, and the system showed a frustrating mix of interface flapping and unexplained downtime. He had verified all. 100G QSFP28 is a hot-pluggable optical transceiver form factor designed to deliver 100-gigabit Ethernet connectivity using four parallel 25-gigabit lanes. The modules arrived on time, passed visual inspection, and seated perfectly in the switch ports. It was only then that they discovered the cabling contractor had installed OS2 single-mode fiber. FS offers a growing portfolio of 100G QSFP28 modules. Click to get your 100GBE transceiver modules from nearby. The term QSFP28 stands for Quad Small Form-factor Pluggable 28. 3 standard for 100G transmissions.