400G OSFP to QSFP-DD Direct Attach Copper Cable (DAC)

• Supports aggregate data rates up to 400Gbps
• OSFP to QSFP-DD connector configuration
• Supports 56G PAM4 electrical data rates per channel
• Compliant with CMIS 4.0, OSFP MSA, and QSFP-DD MSA
• Ethernet compliant with IEEE 802.3cd
• Low crosstalk for improved high-speed signal integrity
• Low power consumption for efficient data center operation
• Supports hot-plugging for convenient installation and maintenance
• Integrated I2C two-wire interface for device monitoring and control
• Maximum link length up to 3 meters
• Designed for short-distance 400G interconnects
• RoHS compliant

• 400G OSFP-to-QSFP-DD switch interconnection
• Data center switch-to-switch connectivity
• Spine-and-leaf network architectures
• High-performance computing (HPC) networks
• AI and GPU cluster networking
• 400G Ethernet server connectivity
• Network equipment interoperability testing
• Short-distance rack and equipment interconnects

OEM and ODM services are available for the 400G OSFP to QSFP-DD DAC Series. Customization options can include cable length, cable labeling, EEPROM configuration, connector identification, and other cable assembly requirements according to the customer’s networking equipment and deployment specifications.

For volume projects, the cable can also be supplied with customized cable assemblies and identification information to support specific system integration and network deployment requirements.

Why use an OSFP-to-QSFP-DD DAC instead of a standard 400G DAC?

The primary advantage is interoperability between equipment using different 400G form factors. An OSFP port on one device can be directly connected to a QSFP-DD port on another device without requiring separate optical modules and fiber cabling.

Can the cable be used for connections between different equipment manufacturers?

Yes, provided that both host devices support the relevant 400G electrical interface, management requirements, and applicable standards. CMIS and MSA compliance helps provide a standardized interface, while equipment-specific compatibility should still be verified before deployment.

What is the role of the I2C interface in the cable?

The I2C two-wire interface allows the host equipment to access management and identification information associated with the cable assembly. This enables functions such as cable identification, monitoring, and host-side management.

Is the cable suitable for high-density data center environments?

Yes. Its low-power electrical architecture and maximum length of up to 3 meters make it particularly suitable for short-distance connections within racks or between closely positioned networking devices. The direct copper design also eliminates the need for separate optical components.

What does 56G PAM4 per channel mean for a 400G connection?

A 400G connection uses multiple high-speed electrical channels operating with PAM4 signaling. A 56G PAM4 electrical rate per channel provides the lane bandwidth required to achieve the overall 400G-class interface while maintaining a practical number of electrical lanes.

What should be considered when selecting the cable length?

The cable should be long enough to accommodate the physical routing between the two devices without excessive slack. Since this is a short-reach copper solution, keeping the cable as short as practical can help simplify cable management and maintain efficient rack airflow. The series supports lengths up to 3 meters.