CAB-Q-4S-100G-0.5MArista 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 densely populated equipment, the fixed 0.5m (2ft) version of Arista Networks CAB-Q-4S-100G-0.5M offers a clearly defined 100G link without separate optical modules or patch cords. The DAC assembly uses QSFP28 to SFP28; its power, mechanical and diagnostic details are listed where supplied so port density and cable management can be assessed together.
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.
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.
High-Density Rack Integration
In a densely populated rack, connector access and airflow are part of the link design. Choose the shortest length that follows the managed path comfortably, avoid tight bundles around the connector housings and preserve room for latch operation. Where power consumption is listed, include every populated interface in the host thermal budget rather than assessing a single cable in isolation. 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).
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.
Quality Assurance and Packaging
Each assembly receives a visual connector inspection and functional link check before it is coiled and protected. Packaging is selected to avoid compressing the cable into a tight bundle, and optional rack-based labels help maintain an orderly installation when many identical interfaces are populated together. Neutral packaging and customer-specific packing documentation are available on request.
Ordering Information
Provide the exact part number, length, quantity and target interface density. For multi-rack projects, list each length separately and identify any preferred carton grouping. Host model and software information can be included for a compatibility review before production or dispatch. Keep CAB-Q-4S-100G-0.5M associated with 0.5m (2ft) throughout the order and receiving record.
Arista Networks Compatibility and Factory Testing
The assembly is evaluated for host recognition and stable link operation, with diagnostics checked where the interface provides them. This approach verifies more than electrical or optical continuity. Exact platform and firmware information remains valuable in high-density deployments because port mode and qualification policy can differ within the same connector family. 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.
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-Q-4S-100G-0.5M refers here to 0.5m (2ft). 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
Standard configurations normally ship within one to three working days, with production quantities confirmed at order stage. Worldwide courier services are available, with air or sea freight for consolidated shipments; freight-collect delivery and coordination with a customer’s logistics provider can be arranged.
