DAC cable CBO QSFP28 to 4×SFP28 direct-attach copper, 3 m length

CBO DAC cable QSFP28 to 4×SFP28, 3 m length, is a direct-attach copper assembly designed for short-reach 100GbE or 4×25GbE connections. The cable integrates a single QSFP28 plug on one end and four SFP28 connectors on the other, enabling direct interconnection between QSFP28 ports and multiple SFP28 ports without separate transceivers. It is intended for data center top-of-rack wiring, switch-to-switch links and server uplinks where low latency, low power consumption and simplified cabling are priorities.

Advantages

The direct-attach copper design delivers low latency and stable signal integrity for short distances while avoiding the cost and power draw of optical transceivers. A pre-terminated QSFP28 to 4×SFP28 configuration allows flexible break-out connections in dense rack environments, reducing the need for additional adapters and simplifying port management. The 3 m length provides sufficient reach for common rack and adjacent-rack layouts while keeping insertion loss and crosstalk low.

Suitable for

• Top-of-rack switch to server uplinks
• Switch-to-switch 100GbE or 4×25GbE connections
• High-density patching and break-out scenarios in data centers
• Short-reach, low-latency connections inside racks or between adjacent racks

Key specifications

• Connector type: QSFP28 to 4×SFP28 copper direct-attach
• Supported data rates: 100GbE or 4×25GbE
• Cable length: 3 meters
• Transmission medium: twinax copper with shielded connectors
• Topology: break-out (1×QSFP28 to 4×SFP28)
• Typical use range: short-reach data center interconnects

How to use

Insert the QSFP28 plug into the source port (for example a 100GbE switch port) and insert the SFP28 plugs into the destination ports (for example four 25GbE server or switch ports). Ensure both ends are fully seated and latches are engaged. Verify link status and speed on connected devices and configure port breakout or lane mapping if required by the switch or host. No transceivers or separate optics are required; the cable provides an integrated electrical connection.

Recommendations

Use the cable for short, direct connections inside racks or between adjacent racks. Avoid routing through sharp bends or subjecting the cable to excessive mechanical stress. Verify compatibility with equipment vendor guidance for QSFP28 break-out and SFP28 port support, and check switch firmware or configuration for required breakout settings.