QSFP28 packs four 25G lanes into one pluggable module to deliver 100G in the QSFP footprint. It is the module class documented on the FF-1102E, the GRT 100G adapter built on the self-developed G810-2Q controller — and the class behind the spine ports of current switch generations.
Within the family, the practical split is reach: multimode variants for in-hall spine-leaf wiring, single-mode variants for campus and metro distances. A second split matters in high-density designs: a QSFP28 port can also break out into four independent 25G SFP28 links, which is how many fabrics stage a 100G-to-25G migration. Ask our team which variant your fabric design assumes.
Pairing with GRT adapters
QSFP28 is the documented module connection on the FF-1102E, the GRT 100G adapter on the self-developed G810-2Q controller. The F1102EBPLR bypass card ships with two 100G single-mode 10 km modules, but its archive does not name their form factor, and the standard E810 model likewise follows its current datasheet — our team will confirm module details for both when you inquire. Card and optics can be evaluated together before a fleet order — loaner units are available under our free testing service.
What fiber does QSFP28 use?
Depending on variant: duplex single-mode (LC) for reach, or parallel multimode (MPO) for short high-density runs. Match the variant to your plant.
Can QSFP28 break out to 4×25G?
Yes, with breakout-capable variants and the right cable assemblies. This is a common migration pattern from 100G spines to 25G servers.