Direct Attach Copper (DAC) cable CBO DAC-QSFP-4SFP28-25G 3m QSFP28 to 4× SFP28, 25Gbps per lane

Passive Direct Attach Copper (DAC) cable CBO DAC-QSFP-4SFP28-25G 3m is a 3-metre copper interconnect that links a QSFP28 port to four SFP28 ports and supports 25 Gbps per lane. Designed for short-reach connections in data centers and server racks, this DAC cable provides a compact, low-latency physical link ideal for high-density environments where multiple 25 GbE lanes must be broken out from a single QSFP28 interface.

Advantages

The cable delivers deterministic, low-latency performance with minimal power consumption because it is a passive copper assembly. Its breakout configuration enables flexible port mapping from one QSFP28 to four SFP28 connectors, reducing the need for additional active transceivers or patching. The 3 m length allows convenient rack-level connections while preserving signal integrity for short-reach links.

Suitable for

• Connecting a QSFP28 port to multiple SFP28 ports in top-of-rack switches
• High-density server interconnects requiring multiple 25 Gbps lanes
• Short-reach links between switches, storage arrays and network interface cards
• Environments prioritizing low latency and reduced power consumption

Key specifications

• Connector type: QSFP28 to 4 × SFP28 breakout
• Data rate: 25 Gbps per lane
• Length: 3 metres
• Cable type: Passive copper direct-attach
• Use case: Short-reach, rack-level interconnects

How to use

Insert the QSFP28 end into the source device port and connect each SFP28 plug to the target device ports. Ensure connectors are fully seated and that both ends are compatible with the host hardware. No external power or configuration is required for passive operation; link parameters are negotiated by the connected devices. Verify network interface settings and lane mapping in switch or host firmware if necessary.

Recommendations

For optimal performance, use this passive DAC for short-distance connections within the same rack or adjacent racks. Avoid tight bends or kinks in the cable and maintain proper airflow around equipment. Confirm compatibility with device vendor hardware before deployment and keep firmware updated to ensure correct lane mapping and link stability.