QSFP-DD 200G / 400G

QSFP-DD, is the smallest form factor for 400G transceivers. It is backward compatible with lower-speed QSFP+, QSFP28 and QSFP56 transceivers and direct attach cables. As demand increases and prices fall it is expected this form factor will become the popular choice for clients, enabling them to reduce the range of form factors they need to manage.

QSDP-DD stands for 'Quad Small Form Factor Pluggable Double Density'. "Double Density” means it supports double the number of high-speed electrical interfaces compared to a standard QSFP28 module. It is fully compliant with IEEE802.3bs and QSFP-DD MSA standards.

To achieve for 200G network transmission, each channel can reach data rates of 25Gb/s through NRZ modulation technology. To achieve 400G network transmission the data rate of each channel can reach 50Gb/s by PAM4 modulation technology. PAM4 is a modulation scheme that combines two bits into a single symbol with four amplitude levels. This effectively doubles a network's data rate, enabling 400G for short-haul transmission.

The QSFP-DD has the same dimensions as the QSFP+, QSFP28, and QSFP56. However, unlike other QSFP modules, the QSFP-DD module has an 8-lane electrical interface instead of a 4-lane, and the ASIC ports of the QSFP-DD are doubled to accommodate existing interfaces such as CAUI-4. To accommodate the extra row of contacts, the mechanical interface of QSFP-DD on the host board is slightly deeper than that of conventional QSFP system transceivers.

Compliant with the following standards & protocols

  • QSFP-DD MSA standards
  • IEEE802.3bs for 400GBASE-DR4, 400GBASE-FR8, 400GBASE-LR8
  • IEEE P802.3cm for 400GBASE-SR8, 400GBASE-SR4.2
  • IEEE P802.3cn for 400GBASE-ER8
  • IEEE P802.3ct for 400GBASE-ZR
  • 100G Lambda MSA for 400GBASE-FR4, 400GBASE-LR4
  • CWDM8 MSA for 400G-CWDM8-2, 400G-CWDM8-10


 Format Reach Media Type Architecture Wavelength
400GBASE-DR4 500m SMF 4x 100G PAM4 1300nm
400GBASE-FR8 2km SMF 8x 50G PAM4 WDM
400GBASE-LR8 10km SMF 8x 50G PAM4 WDM
400GBASE-SR8 100m MMF 8x 50G PAM4 850nm
400GBASE-SR4.2 100m MMF 8x 50G PAM4 BiDi 850/910nm
400GBASE-ER8 40km SMF 8x 50G PAM4 WDM
400GBASE-ZR 80km SMF Coherent DWDM
400GBASE-FR4 2km SMF 4X 100G PAM4 CWDM
400GBASE-LR4 10km SMF 4X 100G PAM4 CWDM
400G-CWDM8-2 2km SMF 8X 50G CWDM
400G-CWDM8-10 10km SMF 8X 50G CWDM
  • Application 400GBASE Data Centre
  • Backward compatible with QSFP+, QSFP28 and QSFP56 transceivers
  • Low Power Consumption <10W
  • LC, MPO, MPO-12 connector depending on product type
  • Single 3.3V Power Supply
  • Hot-Pluggable
  • Commercial Temperature Range 0~70°C
  • RoHS-6 compliant