400G QSFP-DD

400G QSFP-DD transceivers double the QSFP28 lane count from 4 to 8 lanes and run at 50G PAM4, fitting in a backward-compatible cage that accepts QSFP28 / QSFP+ modules at lower rates. This makes it the migration-friendly choice over OSFP for installed fleets. Optiunik supplies the full QSFP-DD reach ladder: DR4 (500 m / SMF via MPO-12 single-fiber), DR4+ (2 km), FR4 (2 km / duplex LC), LR4 (10 km), ER8 (40 km), and ZR / ZR+ coherent (80–120 km). 2× FR4 breakout to 2× 200G is also available. Modules are programmed for Cisco IOS XR / NX-OS, Arista EOS, Nvidia Spectrum / Quantum, Juniper Junos, and Mellanox MLNX-OS coding. Max power 12 W with built-in DDM / I²C diagnostics and CMIS-compliant firmware.