Cisco QSFP-DD Module – 400GBASE Quad Small Form-Factor Pluggable Double Density

The Cisco QSFP-DD Module family defines the pinnacle of bandwidth density for modern data centers, offering a scalable path to 400G networking while preserving backward compatibility with established lower-speed QSFP pluggable modules and cables. Built for high-performance fabrics and dense rack layouts, these modules enable data centers to scale throughput without sacrificing port density, power efficiency, or manageability. Designed to integrate seamlessly with Cisco networking platforms, the QSFP-DD portfolio supports flexible deployment models—from cloud-scale deployments to enterprise campuses—each configured to maximize performance, reduce latency, and simplify cable management. Whether you are modernizing a greenfield data center or upgrading an existing infrastructure, Cisco QSFP-DD modules provide the foundation for a future-ready network that can grow with your organization’s evolving bandwidth needs.

• Maximum bandwidth density: Enables 400G networking in a compact, hot-swappable form factor, delivering unprecedented throughput per port to meet the demands of data-intensive applications, AI workloads, and high-frequency trading environments.
• Backward compatibility: Maintains a seamless upgrade path by supporting interoperability with legacy lower-speed QSFP pluggable modules and cables, allowing gradual migration without overhauling existing infrastructure.
• Flexible cabling and reach: Supports a variety of cabling options, including Direct Attach Copper (DAC) and fiber optic cables, with module variants tailored for SR4, LR4, and other standards to optimize reach and cost per bit.
• Hot-swappable design for minimal downtime: The modular, hot-swappable nature of QSFP-DD components reduces maintenance windows and service disruptions, enabling quick field swaps and upgrades while the network remains online where possible.
• Cisco-ecosystem optimization: Engineered to work in harmony with Cisco switches, routers, and network management tools, enabling streamlined provisioning, monitoring, and lifecycle management through Cisco DNA Center and compatible OS environments.

Technical Details of Cisco QSFP-DD Module

• Data rate: 400GBASE QSFP-DD per port, supporting high-bandwidth applications and scalable data center fabrics.
• Form factor: QSFP-DD (Quad Small Form-Factor Pluggable Double Density) designed for high port density and efficient rack utilization.
• Lane configuration: 4x100 Gbps lanes, enabling flexible mode configurations and compatibility with multi-lane optical signaling standards.
• Compatibility: Backward compatible with select lower-speed QSFP pluggable modules and cables to facilitate smooth upgrades within existing infrastructures.
• Supported cabling options: Supports Direct Attach Copper (DAC) and fiber optic cabling using appropriate transceiver types (e.g., SR4, LR4) depending on the specific module variant.

How to Install Cisco QSFP-DD Module

• Prepare the system: Power down the device or disable the port as recommended by Cisco maintenance procedures to minimize risk during replacement or upgrade.
• Inspect the port and module: Verify that the QSFP-DD port and the module are clean and free of debris; handle the module by the edges to avoid contamination.
• Align and insert: Align the module with the port, ensuring the connector pins are properly seated. Press firmly until the latching mechanism engages and you hear an audible click.
• Attach the cabling: Connect the appropriate DAC or fiber optic cable to the module’s transceiver ports, securing cables to prevent disconnection during operation.
• Verify operation: Power on the device (if applicable) and check the port status in the management interface. Confirm link status, port speed, and error counters to ensure a healthy connection.
• Document and monitor: Record the installation details (module type, serial number, port, and cabling) and monitor performance metrics over time to ensure sustained throughput and reliability.

Frequently Asked Questions

• Q: What is a QSFP-DD module?
  A: A high-density, quad small form-factor pluggable transceiver designed to deliver 400GBASE data rates in a compact, modular package, using four high-speed lanes for scalable network throughput.
• Q: Is the Cisco QSFP-DD module backward compatible with older QSFP modules?
  A: Yes. The Cisco QSFP-DD family is designed to maintain backward compatibility with select lower-speed QSFP pluggables and cables, enabling a phased upgrade path without large-scale overhauls to existing infrastructure.
• Q: What kinds of cables can be used with QSFP-DD?
  A: Depending on the module variant, you can use Direct Attach Copper (DAC) cables or fiber optic cables (such as SR4, LR4) to connect to other devices in the network, optimizing for cost, distance, and power efficiency.
• Q: How do I determine compatibility with Cisco gear?
  A: Refer to Cisco compatibility matrices and the product’s official documentation for supported transceiver types, port speeds, and firmware requirements. In many cases, you can upgrade in place if the port and chassis support 400GBASE QSFP-DD modules.
• Q: What should I consider when planning a 400G deployment with QSFP-DD?
  A: Assess current and projected traffic, select appropriate module variants (SR4/LR4 or DAC), verify cabling quality and length, ensure power and cooling are adequate for higher-density transceivers, and align with your network’s management and monitoring capabilities for optimal performance.
• Q: What is the warranty and support for Cisco QSFP-DD modules?
  A: Warranty and support terms vary by region and product line; consult Cisco’s regional policy and your authorized reseller for precise coverage and service options.