Cisco QDD-400G-4QAC Compatible 400G QSFP-DD 8 x 50G PAM4 to 4 x 100G QSFP56 2 x 50G PAM4 Active Copper Breakout Cable
For equipment that specifies Cisco QDD-400G-4QAC, this HT-manufactured ACC family offers 400G direct-attach connectivity with QSFP-DD to 4x QSFP56. Rather than treating different OEM length codes as interchangeable, the available configurations below link to their own product pages. Mechanical details, installation planning and factory checks are included for engineering and purchasing review.
Series Part Number: QDD-400G-4QACHT Part Number: QDD-400G-4QAC
Product Highlights
- HT-manufactured compatible alternative for Cisco QDD-400G-4QAC
- 400G aggregate connectivity at 400Gb/s
- Interface configuration: QSFP-DD to 4x QSFP56
- Active Twinax
- Length configurations covered: 3m (10ft) and 5m (16ft)
- Conductor specification: 30 AWG
- Power consumption: ＜0.1W
Available Lengths and Corresponding Part Numbers
The documented series configuration is 3m (10ft) and 5m (16ft). Use the relevant OEM reference below together with the HT identity and required length when requesting a quotation. If another length carries a different OEM part number, it must be reviewed and ordered as that distinct configuration.
Compatible OEM Part Numbers
- QDD-400G-4QAC03
Specifications
| HT Part Number | QDD-400G-4QAC |
|---|---|
| Manufacturer | HT |
| Form Factor | QSFP-DD to 4x QSFP56 |
| Max Data Rate | 400Gb/s |
| Cable Length Options Covered | 3m (10ft) and 5m (16ft) |
| Cable Type | Active Twinax |
| Minimum Bend Radius | 70mm |
| Wire AWG | 30 AWG |
| Jacket Material | PVC |
| Power Consumption | ＜0.1W |
| Modulation Format | PAM4 |
| Inbuilt FEC | No |
| Operating Temperature Range | 0 to 70°C (32 to 158°F) |
| Inbuilt FEC | QSFP-DD MSASFF-8679SFF-8636 |
Applications and Deployment
Active copper assemblies add signal conditioning while retaining the convenience of a direct-attached cable. They are appropriate where the equipment supports the stated active-cable type and the route exceeds the practical limits of a comparable passive assembly. Per-end power, airflow and host qualification should be assessed before high-density deployment. For this series, the listed interface is QSFP-DD to 4x QSFP56 and the aggregate rate is 400G.
Cable Construction and Routing
For this assembly, the conductor specification is 30 AWG; the jacket material is PVC; the minimum bend radius is 70mm; the power consumption is ＜0.1W. These parameters belong in the installation review rather than being treated as catalogue trivia. Route the cable through its intended managers without tension, avoid pressure close to the connector boots and leave enough space to operate the latches. Any service loop must respect the stated bend limit.
Procurement and Port-Mapping Review
A useful purchase order should identify the host platform, the expected OEM code and the exact cable length as separate pieces of information. This prevents a physically similar assembly from being substituted when the port identification or reach is different. For mixed-length installations, prepare one order line per part number and reconcile each delivered cable with its intended pair of ports. For this series, keep the interface rate, ACC construction and length-specific OEM reference together throughout that review.
Cisco Compatibility and Factory Testing
Our procurement-oriented compatibility check begins with the OEM reference and ends with a live host link. We record the physical length separately from the identification configuration, so the cable supplied for this page remains the stated version rather than a generic length substitute. Series-level inspection is followed by the exact length and OEM configuration selected for dispatch. Functional verification includes link establishment and diagnostic indications where the host exposes them.
Ordering Information
For a clear bill of materials, quote the OEM reference, HT part number, length and quantity on the same line. Add the switch or server model and software release when a pre-order review is required; project labels can repeat those details for receiving and installation teams. For this series, follow the corresponding length link, quote that exact OEM part number and keep different lengths on separate order lines. HT part number QDD-400G-4QAC identifies the product family; the linked page provides the final length-specific identity.
Quality Assurance and Packaging
Before packing, the assembly is checked for connector condition, identification and link operation. Cables for multi-line orders can be labelled and grouped by part number, making it easier to match each length to the procurement record without opening every protective bag. Both connector ends are inspected as part of the complete assembly, and protective packing is selected to avoid tight bends during transport and storage.
Shipping and Lead Time
Standard configurations normally ship within one to three working days, with production lead times confirmed for larger quantities. International courier, air freight and sea freight are available; customer courier accounts and nominated forwarders are accepted.
Frequently Asked Questions
Is this an original Cisco cable?
No. It is an HT-manufactured compatible cable for equipment that specifies QDD-400G-4QAC, not an original Cisco-branded product.
Are different lengths and OEM part numbers separate products?
Yes. Where a length has its own OEM reference, follow the corresponding link above and order that exact part number on its own line. Do not substitute another length only because the connector arrangement is the same.
Does this ACC cable require separate modules at each end?
No. The connector ends and cable form one complete direct-attach assembly. The ends are not detachable standalone transceivers, and the complete product is tested together.
What information helps confirm compatibility?
Provide the equipment manufacturer and model, port type, hardware revision and software release, together with the required OEM reference, length and quantity. Breakout projects should also identify the intended lane configuration.