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)

For short, high-density connections, this DAC cable combines 400G performance with a fixed 2.5m (8ft) cable run. It corresponds to Cisco QDD-4ZQ100-CU2.5M and uses a factory-terminated passive copper link without separate optical modules or patch cords.

OEM Part Number: QDD-4ZQ100-CU2.5MHT Part Number: QDD-4ZQ100-CU2.5M

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)

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.

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.

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.

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.

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.

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.

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.

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.

Compatibility is more than matching the QSFP-DD to 4x QSFP56 shape. This assembly is prepared for hosts expecting QDD-4ZQ100-CU2.5M and is checked for identification, stable link behavior and electrical continuity, link stability and diagnostic readouts. We recommend confirming the equipment model and software release for critical deployments or mixed-vendor installations.

Use part number QDD-4ZQ100-CU2.5M for the 2.5m (8ft) assembly. For mixed-length projects, list each required part number and quantity separately so that every cable can be tested and packed according to its intended installation.

Production inspection covers both physical condition and a live link check. Connector ends receive individual protection, and the completed assembly is packed without tight ties or sharp bends. For multi-length projects, cartons can be separated and labelled by OEM part number to simplify installation on site.

Stock items are generally dispatched within one to three working days after order confirmation. DHL, UPS, FedEx, TNT and EMS are available for international delivery; larger consolidated orders can move by air or sea freight. Customer courier accounts and nominated forwarders are accepted.