Arista Networks CAB-Q-4S-100G-5M Compatible 100G QSFP28 4 x 25G NRZ to 4 x 25G SFP28 NRZ Passive Copper Twinax Cable, 5m (16ft)

Product Highlights

• Compatible alternative to Arista Networks CAB-Q-4S-100G-5M
• 100G connectivity at 100Gbps
• Interface configuration: QSFP28 to SFP28
• Fixed length and part number: 5m (16ft), CAB-Q-4S-100G-5M
• Cable construction: Passive Twinax
• Conductor specification: 26AWG
• Maximum power consumption: ≤0.125W
• Minimum bend radius: 70mm

Specifications

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 26AWG conductors, PVC (OFNR) jacket, minimum bend radius 70mm. 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 5m (16ft) length gives CAB-Q-4S-100G-5M more freedom for adjacent-rack and row-end deployments. Longer copper runs need particular attention to routing weight and bend control; the DAC specification and host support must still match the intended link.

Position Within the Length Range

CAB-Q-4S-100G-5M is the longest of 8 verified length options in this family. Compared with CAB-Q-4S-100G-3.5M at 3.5m (11ft), it provides 1.5m of additional reach for a longer vertical drop, a wider rack or an adjacent-cabinet route. Confirm that the complete path requires this length, because unused slack still needs supported, bend-safe storage.

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 26AWG; the minimum bend radius is 70mm; the stated power consumption is ≤0.125W; the jacket material is PVC (OFNR).

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. This page’s fixed configuration is 5m (16ft); another length must be quoted under its corresponding part number.

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. Both connectors are examined before the operating test, which includes link stability and diagnostic indications.

Frequently Asked Questions

Shipping and Lead Time

Standard configurations normally ship within one to three working days, with production quantities confirmed at order stage. 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.