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.

Interoperability and Configuration Checks

Check three layers before deployment: the host must accept the cable identification, the port must support the stated aggregate rate, and the lane configuration must match the attached interfaces. On breakout hardware, also confirm channelization and the mapping of every branch. These checks are particularly important when similar-looking ports operate at different speeds or under different firmware settings. 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).

Ordering Information

Specify the OEM part number and fixed length, then provide the intended host configuration if the link uses channelized or breakout ports. Separate part numbers should be used for separate lengths. This gives the compatibility review enough information to check both the physical assembly and the intended operating mode. Quantity and any labeling instructions should be attached specifically to CAB-Q-4S-100G-5M.

Arista Networks Compatibility and Factory Testing

The verification process combines digital identification with a live link test and diagnostic observation. Host model, hardware revision and software release are useful inputs because qualification behavior can change between platform generations; those details allow platform-specific requirements to be reviewed before the cable is packed. Where supported by the host, link stability and diagnostic indications are reviewed together with the established link.

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. 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.

Quality Assurance and Packaging

Functional inspection covers identification, link establishment and the condition of both connector assemblies. The cable is then protected against dust and connector damage and packed without sharp bends. Labels can include the customer reference and host-platform note when requested for a controlled deployment. Volume orders can include customer references on the labels and carton list.

Frequently Asked Questions