Arista CAB-O-4Q-400G-2M Compatible 400G OSFP IHS/Finned Top to 4 x 100G QSFP56 2 x 50G PAM4 Passive Copper Breakout Cable, 2m (7ft)

This page gives procurement and network teams a precise reference for Arista CAB-O-4Q-400G-2M: a 400G DAC assembly in a fixed 2m (7ft) configuration. The OSFP (IHS/Finned Top) to 4x QSFP56 interface, HT ordering identity and verified specifications are presented together so the required cable can be matched to the bill of materials without confusing it with another length.
OEM Part Number: CAB-O-4Q-400G-2MHT Part Number: CAB-O-4Q-400G-2M
Product Highlights
- Compatible alternative to Arista CAB-O-4Q-400G-2M
- 400G connectivity at 400Gbps
- Interface configuration: OSFP (IHS/Finned Top) to 4x QSFP56
- Fixed length and part number: 2m (7ft), CAB-O-4Q-400G-2M
- Cable construction: Passive Twinax
- Conductor specification: 28AWG
- Maximum power consumption: 0.1W (OSFP End) 0.1W (QSFP56 Per End)
- Minimum bend radius: 30mm
Specifications
| HT Part Number | CAB-O-4Q-400G-2M |
|---|---|
| Arista Networks Compatible | CAB-O-4Q-400G-2M |
| Manufacturer | HT |
| Form Factor | OSFP (IHS/Finned Top) to 4x QSFP56 |
| Max. Data Rate | 400Gbps |
| Cable Length | 2m (7ft) |
| Wire AWG | 28AWG |
| Minimum Bend Radius | 30mm |
| Max. Power Consumption | 0.1W (OSFP End) 0.1W (QSFP56 Per End) |
| Media | Copper |
| Cable Type | Passive Twinax |
| Modulation Format | 8x 50G-PAM4 to Quad 2x 50G-PAM4 |
| Jacket Material | PVC (OFNR) |
| Temperature Range | 0 to 70°C (32 to 158°F) |
| Protocols | OSFP MSA, IEEE 802.3cd, CMIS v4.0 |
Signal and Lane Configuration
The listed modulation format is 8x 50G-PAM4 to Quad 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.
Network and Protocol Considerations
The intended application is determined by the host interface and protocol support. Listed interface and protocol references include OSFP MSA, IEEE 802.3cd, CMIS v4.0. Confirm that the host firmware and port configuration support the same operating mode.
Breakout Port Mapping
The OSFP (IHS/Finned Top) 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.
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
CAB-O-4Q-400G-2M 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
CAB-O-4Q-400G-2M occupies the middle of this family between CAB-O-4Q-400G-1M at 1m (3ft) and CAB-O-4Q-400G-3M at 3m (10ft). It adds 1m over the shorter option for extra routing clearance, while the next longer version adds another 1m. Measure the managed path and choose this version when its reach is sufficient without creating the slack associated with the longer assembly.
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 assembly, the listed conductor specification is 28AWG; the minimum bend radius is 30mm; the stated power consumption is 0.1W (OSFP End) 0.1W (QSFP56 Per End); the jacket material is PVC (OFNR).
Power and Thermal Planning
The rated power consumption is 0.1W (OSFP 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.
Cable Construction and Routing
This assembly uses 28AWG conductors, PVC (OFNR) jacket, minimum bend radius 30mm. 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.
Arista 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. Both connectors are examined before the operating test, which includes link stability and diagnostic indications.
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. This page’s fixed configuration is 2m (7ft); another length must be quoted under its corresponding part number.
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. Volume orders can include customer references on the labels and carton list.
Frequently Asked Questions
Is this an original Arista cable?
No. It is an HT-manufactured compatible alternative for equipment that specifies Arista CAB-O-4Q-400G-2M.
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-O-4Q-400G-2M refers here to 2m (7ft). Every other verified length has a separate part number and page in the length list.
Are separate transceivers or patch leads required?
No. This is one complete direct-attach assembly. The ends are not detachable modules and should not be separated from the cable.
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. Delivery can be arranged by courier, air freight or sea freight, and goods may instead be handed to an appointed forwarder or shipped on the customer’s courier account.