DAC cable CBO QSFP28 to 4×SFP28 3 m (QSFP28-4SFP28-DAC-3M)

Passive direct-attach copper (DAC) cable CBO QSFP28 to 4×SFP28, 3 m is a fixed-rate electrical interconnect designed for short-reach, high-bandwidth links. The cable converts a single QSFP28 port into four SFP28 ports, enabling 100GbE split to 4×25GbE or other compatible configurations. It is intended for use in data centers, top-of-rack and end-of-row switch deployments, and server-to-switch connections where low latency and reliable 25 Gbit/s lanes are required.

Advantages

This DAC cable provides a cost-effective and power-efficient way to implement high-density 100GbE to 4×25GbE connectivity without the need for active transceivers or fibre optics. The passive copper construction reduces heat and power consumption compared with active optical solutions and simplifies rack-level cabling by delivering a single physical link that splits into four lanes. Its pre-terminated design minimizes installation time and ensures consistent electrical performance for short-distance interconnects.

Suitable for

• Splitting a QSFP28 100GbE port into four SFP28 25GbE ports in switches and routers
• Server to top-of-rack switch connections in data centers
• Short-reach high-speed links inside racks or between adjacent racks
• Environments requiring low latency and fixed-rate 25 Gbit/s lanes

Key specifications

• Cable type: Passive direct-attach copper (DAC)
• Connector configuration: QSFP28 to 4×SFP28
• Supported lane rate: 25 Gbit/s per SFP28 lane (4 lanes aggregated to 100 Gbit/s)
• Length: 3 meters
• Use case: Short-reach, rack-level interconnects
• Typical environments: Data centers, server rooms, network racks

How to use

Insert the QSFP28 end into the QSFP28 port on the source device and insert each SFP28 connector into the corresponding SFP28 ports on the target device. Ensure both devices support QSFP28 breakout to 4×SFP28 and are powered down or have ports in a safe state if required by the vendor during installation. After seating the connectors, verify link status and lane speeds via device management interfaces or LEDs; the link should operate as four independent 25 Gbit/s lanes or as a combined 100 Gbit/s channel according to equipment capabilities.

Recommendations

Best results are achieved in short-reach interconnects up to the specified 3 m length in controlled data center environments. Confirm compatibility with switch and server vendors for QSFP28-to-4×SFP28 passive DAC use, and avoid exceeding rated bend radius or mechanical stress on connectors and cable assembly to maintain signal integrity.