Arista Networks CAB-Q-S-3M Compatible 40G QSFP+ to 4 x 10G SFP+ Passive Copper Breakout Cable, 3m (10ft)

Product Highlights

• Compatible alternative to Arista Networks CAB-Q-S-3M
• 40G connectivity at 40Gbps
• Interface configuration: QSFP+ to 4 SFP+
• Fixed length and part number: 3m (10ft), CAB-Q-S-3M
• Conductor specification: 30AWG
• Minimum bend radius: 21mm

Specifications

Cable Construction and Routing

This assembly uses 30AWG conductors, PVC (OFNR) jacket, minimum bend radius 21mm. 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.

Position Within the Length Range

CAB-Q-S-3M occupies the middle of this family between CAB-Q-S-2M at 2m (7ft) and CAB-Q-S-4M at 4m (13ft). 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.

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 21mm; the jacket material is PVC (OFNR).

Network and Protocol Considerations

The intended application is determined by the host interface and protocol support. Listed interface and protocol references include SFF-8436, SFF-8431 and QSFP+ MSA. Confirm that the host firmware and port configuration support the same operating mode.

Breakout Port Mapping

The QSFP+ to 4 SFP+ 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

At 3m (10ft), this assembly can bridge non-aligned ports or adjacent racks while remaining a single direct-attach link. Support longer horizontal runs with suitable cable management and preserve space for cooling and future maintenance.

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 3m (10ft); 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. The check includes link stability and diagnostic indications, followed by a final inspection of both ends.

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.