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. 25G SFP28 is the new access/server baseline; deploy it for port density and long-term value. 100G QSFP28 is the mainstream spine/aggregation choice; design for 25G→100G migration. Selection is driven by power, thermal limits, cabling, and O&M risk —not speed alone. SFP-family and QSFP-family. In March 2025, her team ordered 500 QSFP28 SR4 transceivers for a new data center build in Frankfurt. 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. In today's rapidly developing network communication field, the QSFP28 100G optical module is vital. 1 Amphenol's 100G QSFP28 optical modules include SR4, AOC, AOC break out, CWDM4, LR4, ER4 Lite, ER4 and ZR4 series, which adopt LC or MPO optical ports and are compatible with IEEE802. With the increasing demand for network bandwidth and the development of technology, the 100G QSFP28 module is becoming a. The new 100G ZR QSFP28-DCO stands apart as the market's only high-power coherent transceiver in the compact QSFP28 form factor, significantly reducing both power dissipation and network footprint.