Arista Networks CAB-Q-4S-100G-0.5M Compatible 100G QSFP28 4 x 25G NRZ to 4 x 25G SFP28 NRZ Passive Copper Breakout Cable, 0.5m (2ft)

For project documentation, Arista Networks CAB-Q-4S-100G-0.5M and this cable’s physical length should be recorded together. The product described here is a 0.5m (2ft) DAC assembly for 100G links, using QSFP28 to SFP28. Its OEM cross-reference, HT part number, specification table and packing options support traceable ordering and installation records.
OEM Part Number: CAB-Q-4S-100G-0.5MHT Part Number: CAB-Q-4S-100G-0.5M
Product Highlights
- Compatible alternative to Arista Networks CAB-Q-4S-100G-0.5M
- 100G connectivity at 100Gbps
- Interface configuration: QSFP28 to SFP28
- Fixed length and part number: 0.5m (2ft), CAB-Q-4S-100G-0.5M
- Cable construction: Passive Twinax
- Conductor specification: 30AWG
- Maximum power consumption: ≤0.125W
- Minimum bend radius: 60mm
Specifications
| HT Part Number | CAB-Q-4S-100G-0.5M |
|---|---|
| Arista Networks Compatible | CAB-Q-4S-100G-0.5M |
| Manufacturer | HT |
| Form Factor | QSFP28 to SFP28 |
| Max Data Rate | 100Gbps |
| Cable Type | Passive Twinax |
| Cable Length | 0.5m (2ft) |
| Wire AWG | 30AWG |
| Minimum Bend Radius | 60mm |
| Power Consumption | ≤0.125W |
| Power Supply | 3.3V |
| MTBF | =50 Million Hours |
| Jacket Material | PVC (OFNR) |
| Commercial Temperature Range | 0 to 70°C (32 to 158°F) |
| Modulation Format | QSFP28-4x 25G-NRZ SFP28-1x 25G-NRZ |
| Media | Copper |
| Application | 100G to 4x 25G Ethernet, Data Centers |
| Protocols | IEEE 802.3, QSFP28 MSA, SFF-8665 |
Signal and Lane Configuration
The listed modulation format is QSFP28-4x 25G-NRZ SFP28-1x 25G-NRZ. 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.
Power and Thermal Planning
The rated power consumption is ≤0.125W. 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 30AWG conductors, PVC (OFNR) jacket, minimum bend radius 60mm. 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 100G to 4x 25G Ethernet, Data Centers. Listed interface and protocol references include IEEE 802.3, QSFP28 MSA, SFF-8665. Confirm that the host firmware and port configuration support the same operating mode.
Breakout Port Mapping
The QSFP28 to SFP28 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
The 0.5m (2ft) length is suited to closely aligned ports where excessive slack would obstruct airflow or complicate dressing. Measure the actual port-to-port path before choosing CAB-Q-4S-100G-0.5M; even a short assembly must retain the specified bend radius and should never be pulled tight behind the equipment.
Position Within the Length Range
CAB-Q-4S-100G-0.5M is the shortest of 8 verified length options in this family. It is the preferred choice when the port positions are close and cable slack must be kept to a minimum. The next option is CAB-Q-4S-100G-1M at 1m (3ft), adding 0.5m for a less direct routing path; selecting it unnecessarily would leave more cable to dress.
Project Documentation and Cable Identification
Large deployments are easier to audit when the order code, physical length and endpoint record agree. Keep the OEM reference in the compatibility document and use the HT part number on the packing list. Where several lengths arrive together, labels and carton groups can be arranged by rack or port plan so installers do not have to identify cables by appearance alone. For this assembly, the listed conductor specification is 30AWG; the minimum bend radius is 60mm; the stated power consumption is ≤0.125W; the jacket material is PVC (OFNR).
Arista Networks Compatibility and Factory Testing
Factory verification links the compatibility identity to the exact physical assembly described on this page. Identification, connector condition and live link behavior are checked before packing. Customers can submit equipment and firmware details with the project documentation for a more specific pre-order compatibility review. Where supported by the host, link stability and diagnostic indications are reviewed together with the established link.
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-Q-4S-100G-0.5M.
Will any matching connector operate at the same speed?
Not necessarily. Both hosts must support the stated rate, identification, lane mapping and any required breakout configuration; mechanical compatibility alone is insufficient.
What details assist a compatibility review?
Provide the equipment manufacturer, model, port type, hardware revision and software release, together with the OEM reference, required length and quantity.
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.
Ordering Information
Use the listed HT part number for ordering and retain the OEM reference as the host-compatibility cross-reference. Send quantities by length, along with any rack-based packing or label instructions. If the project has mixed equipment, include the host model for each group rather than relying only on the aggregate cable rate. This page’s fixed configuration is 0.5m (2ft); 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. 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.
Quality Assurance and Packaging
Inspection and link testing are completed before the cable enters its protective packaging. Project orders can be packed and labelled by length, rack or customer reference, with packing documentation that makes received quantities straightforward to reconcile against the installation schedule. Standard protective packing is used by default, with project documentation arranged when requested.
