Cisco QDD-4ZQ100-CU3M Compatible 400G QSFP-DD 8 x 50G PAM4 to 4 x 100G QSFP56 2 x 50G PAM4 Passive Copper Breakout Cable, 3m (10ft)

Product Highlights

• Compatible alternative to Cisco QDD-4ZQ100-CU3M
• 400G connectivity at 400Gbps
• Interface configuration: QSFP-DD to 4x QSFP56
• Fixed length and part number: 3m (10ft), QDD-4ZQ100-CU3M
• Conductor specification: 28AWG
• Maximum power consumption: 0.1W (QSFP-DD End)0.1W (QSFP56 Per End)
• Minimum bend radius: 41mm
• Operating temperature: 0 to 70°C (32 to 158°F)

Specifications

Signal and Lane Configuration

The listed modulation format is QSFP-DD-8x 50G-PAM4QSFP56-2x 50G-PAM4. Both host interfaces must be configured for the same aggregate rate and lane arrangement. A connector that fits mechanically does not by itself guarantee that the remote port supports this encoding or breakout mode.

Power and Thermal Planning

The rated power consumption is 0.1W (QSFP-DD End)0.1W (QSFP56 Per End). Include this load in the host-port power and thermal budget, especially in densely populated switches. Maintain front-panel clearance and do not bundle the cable so tightly that it obstructs airflow around the connectors.

Cable Construction and Routing

This assembly uses 28AWG conductors, PVC jacket, minimum bend radius 41mm. These mechanical characteristics affect how the cable should be dressed behind the equipment. Avoid sharp edges, excessive ties and repeated tight bends close to the connector boots.

Network and Protocol Considerations

The intended application is 400G Ethernet. Listed interface and protocol references include SFF-8665, QSFP-DD MSA, IEEE802.3bj, IEEE802.3 cd. Confirm that the host firmware and port configuration support the same operating mode.

Breakout Port Mapping

The QSFP-DD to 4x QSFP56 configuration divides the high-speed interface into multiple lower-speed connections. Verify the upstream lane assignment, downstream port speeds and breakout setting on the host before connecting the assembly. Each branch must attach to the correct remote interface.

Passive Copper Operation

A passive DAC has no separate optical conversion stage. Its low-power, low-latency operation is useful for short equipment links, but the assembly must remain within the length and signaling mode accepted by both hosts.

Length Selection and Installation Planning

At 3m (10ft), this assembly can bridge non-aligned ports or adjacent racks while remaining a single direct-attach link. Support longer horizontal runs with suitable cable management and preserve space for cooling and future maintenance.

Position Within the Length Range

QDD-4ZQ100-CU3M is the longest of 6 verified length options in this family. Compared with QDD-4ZQ100-CU2.5M at 2.5m (8ft), it provides 0.5m of additional reach for a longer vertical drop, a wider rack or an adjacent-cabinet route. Confirm that the complete path requires this length, because unused slack still needs supported, bend-safe storage.

Interoperability and Configuration Checks

Check three layers before deployment: the host must accept the cable identification, the port must support the stated aggregate rate, and the lane configuration must match the attached interfaces. On breakout hardware, also confirm channelization and the mapping of every branch. These checks are particularly important when similar-looking ports operate at different speeds or under different firmware settings. For this assembly, the listed conductor specification is 28AWG; the minimum bend radius is 41mm; the stated power consumption is 0.1W (QSFP-DD End)0.1W (QSFP56 Per End); the jacket material is PVC.

Ordering Information

Specify the OEM part number and fixed length, then provide the intended host configuration if the link uses channelized or breakout ports. Separate part numbers should be used for separate lengths. This gives the compatibility review enough information to check both the physical assembly and the intended operating mode. This page’s fixed configuration is 3m (10ft); another length must be quoted under its corresponding part number.

Cisco Compatibility and Factory Testing

The verification process combines digital identification with a live link test and diagnostic observation. Host model, hardware revision and software release are useful inputs because qualification behavior can change between platform generations; those details allow platform-specific requirements to be reviewed before the cable is packed. Where supported by the host, link stability and diagnostic indications are reviewed together with the established link.

Shipping and Lead Time

Available stock is generally dispatched within one to three working days after order confirmation, with production lead times advised for larger quantities. Worldwide courier services are available, with air or sea freight for consolidated shipments; freight-collect delivery and coordination with a customer’s logistics provider can be arranged.

Quality Assurance and Packaging

Functional inspection covers identification, link establishment and the condition of both connector assemblies. The cable is then protected against dust and connector damage and packed without sharp bends. Labels can include the customer reference and host-platform note when requested for a controlled deployment. Volume orders can include customer references on the labels and carton list.

Frequently Asked Questions