QSFP-DD is a new module and cage/connector system similar to current QSFP, but with an additional row of contacts providing for an eight lane electrical interface. It is being developed by the QSFP-DD MSA as a key part of the industry's effort to enable high-speed solutions. Cisco QSFP-DD and OSFP 800G ZR/ZR+ digital coherent optics modules enable 800G traffic over amplified Dense Wavelength-Division Multiplexing (DWDM) links up to 120 km for 800ZR and over 1000 km for 800G ZR+. In recent times, the advent of 400G DWDM coherent pluggable optical modules has spurred the development of coherent DWDM. At the heart of this leap forward lies QSFP-DD (Quad Small Form Factor Pluggable Double Density) — an enhanced version of the proven QSFP form factor, designed to double the lane density and support data rates up to 400Gbps and beyond.
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