QSFP28 combines four 25Gb/s electrical lanes in a compact, hot-swappable module and remains one of the most widely deployed 100GbE form factors. Selecting the correct optical interface requires matching reach, fiber plant, connector and switch support.
Common 100G interfaces
SR4 uses parallel multimode fiber and an MPO connector for short data center links. LR4 carries four LAN-WDM wavelengths over a duplex LC single-mode pair for links up to 10km. ER4 extends that model to longer metro or campus links. PSM4 uses parallel single-mode lanes, while CWDM4 multiplexes four wavelengths for cost-effective 2km applications.
Compatibility and diagnostics
The mechanical QSFP28 form factor does not guarantee that every optical mode is supported by a switch. Confirm the hardware platform, operating system and port configuration. DDM/DOM telemetry should be enabled so operations teams can monitor temperature, voltage, bias current and transmit/receive optical power.
Deployment checklist
- Match the optic to fiber type and connector polarity.
- Validate total insertion loss against the link power budget.
- Specify OEM coding for each target switch platform.
- Clean and inspect every connector before commissioning.
OPTONE tests QSFP28 modules on target OEM platforms and provides a three-year warranty.
Need help selecting the right product?
Share your switch platform, link distance and quantity with an OPTONE engineer.
Talk to an Engineer →