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.

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.

Rack Layout and Service Access

Plan the managed route before removing the connector protection. The cable should reach both ports without tension while leaving enough space to release the latches and service adjacent interfaces. Support the run through the intended managers, keep the connector boots clear of sharp edges and avoid storing excess length in a tight coil behind warm exhaust air. 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.

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.

Quality Assurance and Packaging

The completed cable is inspected at both ends, functionally tested and coiled with bend-safe slack. Protective packaging keeps the latches and boots from taking impact, while optional project labels can identify the two endpoint locations for easier field service. Standard protective packing is used by default, with project documentation arranged when requested.

Cisco Compatibility and Factory Testing

Compatibility is verified as part of a complete installation check: connector inspection, host identification and an operating link. The physical cable is evaluated together with the expected OEM identity, because a connector that fits is not sufficient evidence that the host will accept and operate the assembly correctly. The check includes link stability and diagnostic indications, followed by a final inspection of both ends.

Frequently Asked Questions

Ordering Information

When requesting this assembly, include the exact part number and length together with the destination port types. For a rack installation, a simple port-to-port list helps us keep different lengths separate and allows any requested labels to correspond with the actual installation sequence. Keep QDD-4ZQ100-CU2.5M associated with 2.5m (8ft) throughout the order and receiving record.

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.