Form factors
Per-form-factor technical reference, MSA refs, electrical interface, power draw, FEC requirements, supported reach classes, switch platforms in production, and example SKUs.
Connectivity Planner
Not sure which form factor your link calls for?
The Connectivity Planner picks it for you from speed and reach (400G LR4 → QSFP-DD; 800G SR8 → OSFP; 400G coherent 80 km → QSFP-DD ZR). Skip the per-form-factor research.
SFP
The Gigabit workhorse. Campus access, branch uplinks, legacy refreshes.
SFP+
The 10G workhorse, server access, building backbones, branch core.
SFP28
25G server access, the current default for new server NICs.
QSFP+
40G aggregation, four parallel 10G lanes in one cage.
QSFP28
The current 100G data-center fabric standard.
QSFP56
200G PAM4, four lanes at 50G each, mostly seen in HPC and storage.
QSFP112
400G in a QSFP envelope — four lanes of 100G PAM4.
QSFP-DD
400G in a double-density QSFP envelope — eight lanes of 50G PAM4.
OSFP
The 800G workhorse, eight lanes of 100G PAM4 for AI/ML and hyperscale.