DAC cable CBO QSFP28-DAC-3M 3 m passive copper QSFP28 direct attach

The BlueOptics DAC cable CBO QSFP28-DAC-3M is a 3 metre passive copper direct-attach cable engineered for QSFP28 ports. Designed for short-reach connections, this QSFP28 DAC assembly provides a low-latency, cost-effective link between switches, routers and servers that support QSFP28 interfaces. Its passive copper construction eliminates the need for optical transceivers or additional power, simplifying rack-level cabling and enabling high-density connectivity in data centre top-of-rack and aggregation environments.

Advantages

The passive design delivers low power consumption and minimal latency compared with active optical or transceiver-based solutions. A fixed 3 m length reduces signal reflections and insertion loss for short links while offering plug-and-play compatibility with standard QSFP28 ports. The cable assembly is space-efficient for dense installations and lowers total cost of ownership by removing separate transceivers or external power requirements.

Suitable for

• Top-of-rack switch-to-switch connections in data centres
• Server-to-switch short-reach interconnects
• Aggregation or spine links within network racks
• High-density deployments requiring low-latency copper connectivity

Key specifications

• Connector type: QSFP28 to QSFP28 direct-attach copper
• Cable length: 3 m
• Passive construction (no active electronics or external power)
• Suitable for 100 Gbps QSFP28 interfaces (short-reach applications)
• Form factor: twinax cable with QSFP28 module assemblies
• Designed for rack-level, short-distance links

How to use

Install the DAC cable by inserting each QSFP28 plug into the corresponding QSFP28 port on your networking equipment until the latch engages. Ensure both devices are powered off or follow hot-plug procedures recommended by the equipment vendor before insertion or removal. The passive DAC is recognized by QSFP28-compliant ports and requires no firmware or driver configuration beyond standard port setup in your switch or server management interface.

Recommendations

Use this 3 m passive QSFP28 DAC for short, rack-level connections where 100 Gbps performance and low latency are required. Avoid routing the cable tightly around sharp edges or kinking the twinax bundle; maintain gentle bend radii and secure the cable to prevent strain on the QSFP28 plugs. Verify compatibility with your switch or server vendor’s QSFP28 port guidance and operate within the recommended ambient temperature range for your equipment.