The QSFP-DD modules are our new generation of 400G transceiver modules based on a QSFP-DD form factor. Cisco has expanded the range of 400G digital coherent QSFP-DD transceivers with the 400G QSFP-DD. Abstract: This specification defines: the electrical and optical connectors, electrical signals and power supplies, mechanical and thermal requirements of the pluggable QSFP Double Density (QSFP-DD) module, connector and cage system. This document provides a common specification for systems. Quad Small Form-factor Pluggable Double Density (QSFP-DD) solution that fits into high-density switch and router client ports for optical interconnect links Powered by Greylock and Delphi DSP ASICs, and silicon photonic integrated circuits (PICs) for an optimized co-packaged design with 3D. 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. The wide variety of modules gives you flexible and cost-effective options for all types of interfaces. Cisco offers a range of GBIC, SFP, XFP, SFP+, CXP, CFP, Cisco CPAK, and QSFP+ pluggable modules.