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Cisco QDD-400-CU2M Compatible 400G QSFP-DD 8 x 50G PAM4 Passive Copper Twinax Cable, 2m (7ft)

Cisco QDD-400-CU2M Compatible 400G QSFP-DD 8 x 50G PAM4 Passive Copper Twinax Cable, 2m (7ft)

For short, high-density connections, this DAC cable combines 400G performance with a fixed 2m (7ft) cable run. It corresponds to Cisco QDD-400-CU2M and uses a factory-terminated passive copper link without separate optical modules or patch cords.

OEM Part Number: QDD-400-CU2MHT Part Number: QDD-400-CU2M

Product Highlights

  • Compatible alternative to Cisco QDD-400-CU2M
  • 400G connectivity at 400Gbps
  • Interface configuration: QSFP-DD to QSFP-DD
  • Fixed length and part number: 2m (7ft), QDD-400-CU2M
  • Cable construction: Passive Twinax
  • Conductor specification: 28AWG
  • Maximum power consumption: 0.1W Per End
  • Minimum bend radius: 39.5mm

Specifications

HT Part NumberQDD-400-CU2M
Cisco CompatibleQDD-400-CU2M
ManufacturerHT
Form FactorQSFP-DD to QSFP-DD
Max. Data Rate400Gbps
MediaCopper
Cable TypePassive Twinax
Cable Length2m (7ft)
Wire AWG28AWG
Minimum Bend Radius39.5mm
Max. Power Consumption0.1W Per End
Jacket MaterialPET (OFNR)
Commercial Temperature Range0 to 70°C (32 to 158°F)
Modulation Format8x 50Gbps PAM4
Application400G Ethernet
ProtocolsIEEE 802.3cd, QSFP-DD MSA, CMIS 4.0

Signal and Lane Configuration

The listed modulation format is 8x 50Gbps 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, PET (OFNR) jacket, minimum bend radius 39.5mm. 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 IEEE 802.3cd, QSFP-DD MSA, CMIS 4.0. Confirm that the host firmware and port configuration support the same operating mode.

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

QDD-400-CU2M provides 2m (7ft) for connections between separated rack units or nearby equipment positions. Plan the route around cable managers and power cords, keeping the assembly free from connector strain while avoiding a large obstruction in the airflow path.

Position Within the Length Range

QDD-400-CU2M occupies the middle of this family between QDD-400-CU1.5M at 1.5m (5ft) and QDD-400-CU2.5M at 2.5m (8ft). 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.

Power and Thermal Planning

The rated power consumption is 0.1W 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

For this Cisco application, testing combines digital identification with actual traffic-link verification and electrical continuity, link stability and diagnostic readouts. Both ends are inspected for latch, boot and connector damage. If the project uses a specific hardware revision or a channelized port, send those details so that the intended configuration can be reviewed before shipment.

Ordering Information

Use part number QDD-400-CU2M for the 2m (7ft) 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.

Frequently Asked Questions

Is this an original Cisco cable?

No. It is an HT-manufactured compatible alternative for equipment that specifies Cisco QDD-400-CU2M.

Can I use it between different speeds or interface types?

Only when both hosts explicitly support the same data rate, lane mapping and breakout configuration. Mechanical fit alone is not proof of interoperability.

What information should I provide for a compatibility check?

Provide the host manufacturer, equipment model, port type, hardware revision and software release, together with the OEM part number and required quantity.

Does this page include more than one cable length?

No. This page is dedicated to 2m (7ft) and part number QDD-400-CU2M. Other lengths have their own part numbers and product pages.

Quality Assurance and Packaging

HT inspects and tests every completed cable before it enters finished stock. Protective caps or covers are fitted where applicable, followed by anti-static or tray packaging and an outer carton. Custom labels can cross-reference the customer part number, QDD-400-CU2M and the 2m (7ft) length for easier inventory control.

Shipping and Lead Time

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.

 

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