Arista Networks CAB-Q-4S-100G-3.5M Compatible 100G QSFP28 4 x 25G NRZ to 4 x 25G SFP28 NRZ Passive Copper Breakout Cable, 3.5m (11ft)

Use the CAB-Q-4S-100G-3.5M compatible assembly where a 100G connection is required between compatible ports. This page covers the 3.5m (11ft) version only, with its own HT part number, specifications and compatibility verification.

OEM Part Number: CAB-Q-4S-100G-3.5MHT Part Number: CAB-Q-4S-100G-3.5M

Product Highlights

• Compatible alternative to Arista Networks CAB-Q-4S-100G-3.5M
• 100G connectivity at 100Gbps
• Interface configuration: QSFP28 to SFP28
• Fixed length and part number: 3.5m (11ft), CAB-Q-4S-100G-3.5M
• Cable construction: Passive Twinax
• Conductor specification: 26AWG
• Maximum power consumption: ≤0.125W
• Minimum bend radius: 70mm

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.

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.

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.

The 3.5m (11ft) length gives CAB-Q-4S-100G-3.5M 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.

CAB-Q-4S-100G-3.5M occupies the middle of this family between CAB-Q-4S-100G-3M at 3m (10ft) and CAB-Q-4S-100G-5M at 5m (16ft). It adds 0.5m over the shorter option for extra routing clearance, while the next longer version adds another 1.5m. Measure the managed path and choose this version when its reach is sufficient without creating the slack associated with the longer assembly.

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.

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.

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.

Each CAB-Q-4S-100G-3.5M compatible cable is powered up on a suitable test interface rather than checked only for continuity. We confirm the expected identification and observe electrical continuity, link stability and diagnostic readouts. Because operating systems can apply different qualification rules by hardware revision, the intended Arista Networks platform should be included with the order.

This product is ordered as CAB-Q-4S-100G-3.5M in 3.5m (11ft). Include the equipment model and software release if you would like a pre-order compatibility review. Other lengths use different part numbers and should not be substituted into the same order line.

HT inspects and tests every completed cable before it enters finished stock. Protective caps or covers are fitted where applicable, followed by anti-static or tray packaging and an outer carton. Custom labels can cross-reference the customer part number, CAB-Q-4S-100G-3.5M and the 3.5m (11ft) length for easier inventory control.

Stock items are generally dispatched within one to three working days after order confirmation. DHL, UPS, FedEx, TNT and EMS are available for international delivery; larger consolidated orders can move by air or sea freight. Customer courier accounts and nominated forwarders are accepted.