Arista Networks CAB-D-D-400G-2.5M Compatible 400G QSFP-DD 8 x 50G PAM4 Passive Copper Twinax Cable, 2.5m (8ft)
This 2.5m (8ft) DAC assembly is made for installations that call for Arista Networks CAB-D-D-400G-2.5M at 400G. The QSFP-DD to QSFP-DD connectors and cable arrive as one complete product, ready for a direct link between suitable ports. Field-handling guidance, exact specifications and pre-packing functional checks apply to the part number shown here.
OEM Part Number: CAB-D-D-400G-2.5MHT Part Number: CAB-D-D-400G-2.5M
Product Highlights
- Compatible alternative to Arista Networks CAB-D-D-400G-2.5M
- 400G connectivity at 400Gbps
- Interface configuration: QSFP-DD to QSFP-DD
- Fixed length and part number: 2.5m (8ft), CAB-D-D-400G-2.5M
- Cable construction: Passive Twinax
- Conductor specification: 26AWG
- Maximum power consumption: 0.1W Per End
- Minimum bend radius: 57mm
Specifications
| HT Part Number | CAB-D-D-400G-2.5M |
|---|---|
| Arista Networks Compatible | CAB-D-D-400G-2.5M |
| Manufacturer | HT |
| Form Factor | QSFP-DD to QSFP-DD |
| Max. Data Rate | 400Gbps |
| Media | Copper |
| Cable Type | Passive Twinax |
| Cable Length | 2.5m (8ft) |
| Wire AWG | 26AWG |
| Minimum Bend Radius | 57mm |
| Max. Power Consumption | 0.1W Per End |
| Jacket Material | PET |
| Commercial Temperature Range | 0 to 70°C (32 to 158°F) |
| Modulation Format | 8x 50Gbps PAM4 |
| Application | 400G Ethernet |
| Protocols | IEEE 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.
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 CAB-D-D-400G-2.5M reaches both ports without tension at either connector.
Position Within the Length Range
CAB-D-D-400G-2.5M occupies the middle of this family between CAB-D-D-400G-2M at 2m (7ft) and CAB-D-D-400G-3M 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.
Field Installation and Maintenance
Inspect the route and both connectors before installation, then support the cable without pulling on either connector housing. During maintenance, release the latch properly rather than using the cable as a handle. Keep protection on unused ends, and if the assembly is removed for later use, coil it loosely and record its part number so the same length can be returned to service. For this assembly, the listed conductor specification is 26AWG; the minimum bend radius is 57mm; the stated power consumption is 0.1W Per End; the jacket material is PET.
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.
Cable Construction and Routing
This assembly uses 26AWG conductors, PET jacket, minimum bend radius 57mm. 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.
Quality Assurance and Packaging
The cable and both connectors are inspected before a functional link test. Connector protection and bend-safe packing reduce handling damage during transport and storage. Customer or site labels can be added for field inventories, with different lengths separated to simplify issue and return of spare assemblies. Volume orders can include customer references on the labels and carton list.
Arista Networks Compatibility and Factory Testing
A field-ready cable needs both correct identification and a stable operating link. Our pre-packing check therefore includes the connectors, host recognition and link behavior. For equipment with uncertain revision history, providing the host model and software release helps identify compatibility requirements before the assembly reaches the installation site. The check includes link stability and diagnostic indications, followed by a final inspection of both ends.
Frequently Asked Questions
Is this an original Arista Networks cable?
No. It is an HT-manufactured compatible alternative for equipment that specifies Arista Networks CAB-D-D-400G-2.5M.
How should an unused assembly be stored?
Protect both connector ends, keep the cable in a loose bend-safe coil and retain its part-number label so the length and compatibility identity remain traceable.
Can different brands be connected with the same assembly?
Only where both hosts explicitly support the complete interface and compatibility arrangement. Document each end and select the appropriate brand-specific product when required.
Does this order code cover multiple lengths?
No. CAB-D-D-400G-2.5M refers here to 2.5m (8ft). Every other verified length has a separate part number and page in the length list.
Ordering Information
Request the cable by its exact part number and length, and state the equipment model if compatibility confirmation is needed. Site orders can list quantities by rack or installation team. Any requested label should retain the part number so a removed or spare cable can still be identified accurately. This page’s fixed configuration is 2.5m (8ft); another length must be quoted under its corresponding part number.
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. International express, air cargo and sea freight can be selected according to destination and carton volume; customer courier accounts and nominated forwarders are also accepted.
