Keep high-speed fabric links simple, short, and predictable with this Cisco to NVIDIA Mellanox compatible 400G DAC. Designed for environments where latency, power draw, and cable management matter, it connects a QSFP-DD host port to two QSFP56 endpoints in a 3 m passive copper assembly. That makes it a practical fit for top-of-rack to adjacent-rack connections, aggregation layers, and tightly packed compute clusters. This cable is built around 400GBASE-CR4 signaling and a 2 x 200G QSFP56 breakout architecture, giving infrastructure teams a clean way to map one high-density port into two downstream links without adding optics, patch panels, or extra transceivers. For procurement teams, the TAA-compliant designation helps support regulated purchasing requirements. For operations teams, the direct attach design reduces component count and simplifies troubleshooting compared with multi-part optical paths. Choose this model when you need a cost-conscious interconnect that still respects the realities of production networks: limited rack depth, high port density, and the need to keep airflow and power budgets under control. It is a straightforward answer for short-reach 400G deployments where reliability and compatibility matter more than marketing claims.