Cisco QDD-4ZQ100-CU2.5M Compatible 400G QSFP-DD 8 x 50G PAM4 to 4 x 100G QSFP56 2 x 50G PAM4 Passive Copper Breakout Cable, 2.5m (8ft)

Product Highlights

• Compatible alternative to Cisco QDD-4ZQ100-CU2.5M
• 400G connectivity at 400Gbps
• Interface configuration: QSFP-DD to 4x QSFP56
• Fixed length and part number: 2.5m (8ft), QDD-4ZQ100-CU2.5M
• 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.

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

The 2.5m (8ft) version is useful when a two-metre run would leave insufficient working slack. Before installation, check the complete horizontal and vertical path so that QDD-4ZQ100-CU2.5M reaches both ports without tension at either connector.

Position Within the Length Range

QDD-4ZQ100-CU2.5M occupies the middle of this family between QDD-4ZQ100-CU2M at 2m (7ft) and QDD-4ZQ100-CU3M at 3m (10ft). It adds 0.5m over the shorter option for extra routing clearance, while the next longer version adds another 0.5m. Measure the managed path and choose this version when its reach is sufficient without creating the slack associated with the longer assembly.

Mixed-Vendor Network Operation

A mixed-vendor link should be documented at both ends, not treated as one generic connection. Confirm which OEM identity each host expects and whether the two ends use the same compatibility requirement. The related brand links below help locate equivalent-length assemblies, while the physical form factor and lane arrangement must still agree across the complete path. 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.

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.

Cisco Compatibility and Factory Testing

Testing addresses the brand-specific identification as well as the operating link and available diagnostics. The same physical cable family can require a different host identity for another equipment vendor, so the intended platform should be supplied when a deployment combines multiple brands or unusual hardware revisions. Both connectors are examined before the operating test, which includes link stability and diagnostic indications.

Ordering Information

For mixed-vendor projects, identify the equipment at both ends along with the OEM reference, length and quantity. Order each compatibility version under its own part number. If spare assemblies are required, list them separately so labels and test records remain unambiguous. Quantity and any labeling instructions should be attached specifically to QDD-4ZQ100-CU2.5M.

Quality Assurance and Packaging

Both ends are inspected and the complete assembly is powered up for a functional check before packing. Connectors are protected individually and the cable is secured without tight bends. Optional labels can distinguish host brand, OEM reference and length for easier spares management. Volume orders can include customer references on the labels and carton list.

Frequently Asked Questions

Shipping and Lead Time

Standard configurations normally ship within one to three working days, while production quantities are confirmed with the order. 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.