An SFP network card carries an empty optical cage instead of a fixed port. The transceiver module you insert decides the medium: multimode for in-rack runs, single-mode for campus distances, a copper module for a legacy RJ45 drop. That separation is why cage-based adapters dominate data-centre design — the server fleet standardises on one card while each rack wires optics to its own geography.
GRT builds cage-based adapters at every tier: gigabit SFP for access and management, 10G SFP+ as the volume standard, 25G SFP28 for current servers and QSFP28 at 100G. And because the same company manufactures the modules, card and optics come from one documented range — loaner units are available under our free testing service so a combination can be proven on your own server before a fleet order.
Can one card serve both single-mode and multimode?
Yes — the cage is media-agnostic. Insert the module that matches your fiber; the card electronics work with either.
Do you code modules for specific switch brands?
Module identity data is prepared for platform compatibility across the industry, and hosts differ in how strictly they check it. Mention your switch models when ordering optics, and prove a pairing with a loaner unit before committing to a fleet order.