Arista Networks CAB-D-8S-400G-2.5M Compatible 400G QSFP-DD 8 x 50G PAM4 to 8 x 50G SFP56 50G PAM4 Passive Copper Breakout Cable, 2.5m (8ft)

The HT-manufactured CAB-D-8S-400G-2.5M compatible cable provides 400G connectivity for Arista Networks equipment. This 2.5m (8ft) version is a factory-terminated passive copper link without separate optical modules or patch cords, with an exact part number and length that can be matched directly to the equipment requirement.

OEM Part Number: CAB-D-8S-400G-2.5MHT Part Number: CAB-D-8S-400G-2.5M

Product Highlights

• Compatible alternative to Arista Networks CAB-D-8S-400G-2.5M
• 400G connectivity at 400Gbps
• Interface configuration: QSFP-DD to 8x SFP56
• Fixed length and part number: 2.5m (8ft), CAB-D-8S-400G-2.5M
• Cable construction: Passive Breakout DAC
• Conductor specification: 28AWG
• Maximum power consumption: 0.1W (QSFP-DD End)0.1W (SFP56 Per End)
• Minimum bend radius: 39.5mm

The listed modulation format is QSFP-DD-8x 50G-PAM4SFP56-50G-PAM4. 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.

CAB-D-8S-400G-2.5M occupies the middle of this family between CAB-D-8S-400G-2M at 2m (7ft) and CAB-D-8S-400G-3M at 3m (10ft). It adds 0.5m over the shorter option for extra routing clearance, while the next longer version adds another 0.5m. 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 0.1W (QSFP-DD End)0.1W (SFP56 Per End). 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 28AWG conductors, PVC (OFNR) jacket, minimum bend radius 39.5mm. 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 determined by the host interface and protocol support. Listed interface and protocol references include QSFP-DD MSA, SFF-8432, IEEE 802.3bs-400GAUI-8, IEEE802.3cd-50GAUI-1, CMIS 4.0, SFF-8472. Confirm that the host firmware and port configuration support the same operating mode.

The QSFP-DD to 8x SFP56 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 2.5m (8ft) version is useful when a two-metre run would leave insufficient working slack. Before installation, check the complete horizontal and vertical path so that CAB-D-8S-400G-2.5M reaches both ports without tension at either connector.

The assembly is configured for equipment that recognizes CAB-D-8S-400G-2.5M. Before shipment, we inspect both connectors and verify identification, link establishment and electrical continuity, link stability and diagnostic readouts. Host hardware and firmware revisions can affect third-party cable acceptance, so customers can provide the equipment model and software release for a pre-order compatibility review.

This product is ordered as CAB-D-8S-400G-2.5M in 2.5m (8ft). 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.

Before packing, our team checks the cable jacket, connector boots, latches and identification of each assembly. The cable is then secured in a loose coil and protected against dust and connector impact. Neutral packaging, customer part-number labels and project-specific carton lists can be supplied on request.

Standard configurations normally ship within one to three working days. Worldwide courier, air freight and sea freight options are available, and shipments can also be sent on your own courier account or delivered to an appointed forwarder.