QDD-400-CU3M – 400G QSFP-DD DAC – 3m Passive Copper – Direct Link
Why Layer23-Switch
Stocked, Shipped and Supported by One Team
Ships in 1 Business Day
In-stock orders leave our Hong Kong or U.S. warehouse within 1 business day after payment, with tracking by email.
LSCare Warranty
3years on enterprise equipment
Free CCIE Support
Certified engineers help before and after you buy. Reply within 1 business day by email or live chat.
Verify Before You Pay
100%factory-sealed
Get label and serial photos before shipment, and check every serial number with Cisco.
QDD-400-CU3M Description
The QDD-400-CU3M is a Cisco 400G QSFP-DD passive copper direct-attach cable for 3 m links inside a rack or between adjacent racks. The cable has a QSFP-DD connector at each end, no optical interface, a 1.5W maximum draw per end and a 0 to 70°C operating range. The cable carries 400 Gigabit Ethernet with forward error correction performed on the host platform.
Quick Specs
|
Parameter |
Specification |
|---|---|
|
Product ID |
QDD-400-CU3M |
|
Product type |
400G QSFP-DD passive copper cable |
|
Cable assembly type |
Passive copper direct-attach cable assembly |
|
Connector form |
QSFP-DD to QSFP-DD |
|
Data rate |
400 Gigabit Ethernet |
|
Cable length |
3 meters |
|
Pull tab color |
Orange |
|
Maximum power consumption |
1.5W per end |
|
Module weight |
600 g maximum |
|
Operating temperature class |
Copper cable operation 0 to 70°C |
|
Compatibility reference |
Cisco Transceiver Module Group Compatibility Matrix |
Application Scenarios
In an AI or data center fabric, the cable joins QSFP-DD 400G ports on neighboring racks over a 3 m passive copper run that adds only 1.5W per end.
On a Catalyst 9600 Series core, the cable connects C9600X-LC-32CD line-card ports to nearby 400G QSFP-DD ports, a use listed in the Cisco IOS XE 17.13.x release notes.
Product Comparison
|
Parameter |
QDD-400-CU3M |
QDD-400-CU2.5M |
QDD-4ZQ100-CU3M |
QDD-400-AOC3M |
|---|---|---|---|---|
|
Cable assembly type |
Passive copper cable assembly |
Passive copper cable assembly |
Passive copper breakout cable assembly |
Active optical cable assembly |
|
Connector form |
QSFP-DD to QSFP-DD |
QSFP-DD to QSFP-DD |
QSFP-DD to 4x QSFP56 |
QSFP-DD to QSFP-DD |
|
Link length |
3 meters |
2.5 meters |
3 meters |
3 meters |
|
Maximum power consumption |
1.5W per end |
1.5W per end |
1.5W per end |
12W per end |
|
Module weight |
600 g maximum |
550 g maximum |
800 g maximum |
190 g maximum |
|
Operating temperature |
0 to 70°C |
0 to 70°C |
0 to 70°C |
0 to 70°C |
QDD-400-CU3M is the 3 m direct QSFP-DD to QSFP-DD passive copper cable of this group at 1.5 W per end, while QDD-400-CU2.5M is the same cable class at 2.5 m, so a rack path that needs the extra half meter stays on QDD-400-CU3M. A port that must split into four 100G endpoints needs QDD-4ZQ100-CU3M, a 3 m passive breakout cable to four QSFP56 100GBASE-CR2 ends. Where the same 3 m run needs active optical media, QDD-400-AOC3M carries 400G at 12 W per end and 190 g, against 1.5 W and 600 g for the copper cable.
Ordering Checklist
- Catalyst 9600 hosts: Use the cable with the C9600X-LC-32CD line card, which lists QDD-400-CU3M alongside QDD-400-CU1M, QDD-400-CU2M and QDD-400-CU2.5M. The cable is listed for this Catalyst 9600 line card.
- UCS hosts: Use the cable on Cisco UCS 6652 Fabric Interconnect QSFP-DD ports. It is listed as uplink-only 400GbE media on the UCS 6652.
Specifications
| Parameter | Specification | Parameter | Specification |
|---|---|---|---|
| Product ID | QDD-400-CU3M | Product type | 400G QSFP-DD passive copper cable |
| Cisco ordering description | 400G QSFP-DD Transceiver, Passive Copper Cable, 3 meters | Cable assembly type | Passive copper cable assembly |
| Connector form | QSFP-DD to QSFP-DD | Optical connector | No optical connector for passive copper cable |
| Data rate | 400 Gigabit Ethernet | Nominal data rate | 425 Gbps |
| High-speed electrical interface | 400GAUI-8 C2M and OIF CEI-56G-VSR-PAM4 | Link length | 3 meters |
| Maximum power consumption | 1.5W per end | Pull tab color | Orange |
| Module weight | 600 g maximum | Module dimension with pull tab | 8.5 x 18.4 x 78.3/93.3 mm |
| Copper cable operation temperature | 0 to 70°C | Storage temperature | -40 to 85°C |
| FEC location | Performed on the host platform | Catalyst support example | C9600X-LC-32CD line card in Cisco IOS XE 17.13.x release notes |
| UCS media listing | Cisco UCS 6652 QSFP-DD uplink-only 400GbE media list | Compatibility reference | Cisco Transceiver Module Group Compatibility Matrix |
Quality Certifications
Customer Reviews
Questions & Answers
-
What link length does QDD-400-CU3M support?
-
What operating temperature range does QDD-400-CU3M support?
-
Is QDD-400-CU3M listed for the NCS 1004 client ports?
-
What electrical interface and data rate does QDD-400-CU3M use?
-
What storage temperature range applies to QDD-400-CU3M?
-
What are the module dimensions of QDD-400-CU3M with pull tab?
Warranty
Layer23-Switch.com offers genuine, high-quality ICT products at competitive wholesale prices—ensuring exceptional value without compromising quality.
All items are brand new, original, and factory-sealed.
Upon request, each unit can be fully tested and verified by a Cisco CCIE-certified engineer to ensure perfect working condition before shipment.
Our Cisco CCIE-certified experts provide free professional support via phone, email, online chat, or remote login—helping you deploy and troubleshoot with confidence.
If you are not satisfied with your purchase, you may request an exchange or full refund. Our customer service team will guide you through the return process quickly and smoothly. Visit Return Policy page for more information.
We support multiple secure payment and logistics options, backed by industry-leading verification:
Visit How to Pay page for more information
Extended, Worry-Free Warranty Coverage Factory New Sealed Enterprise Hardware:
· 3 Years Factory New Sealed
Visit Warranty Policy page for more information
Verify, plan, and comparewith confidence
Use practical tools to check device details, review lifecyclemilestones, and compare hardware before you buy.
Our experience with Layer23 has been universally positive across multiple orders.
Returned for our second order within weeks. No regrets.
Will be doing business with Layer23 again soon. They’ve earned it.