DAC cable CBO QSFP28-DAC-0.5M 0.5m passive copper QSFP28 to QSFP28

CBO QSFP28-DAC-0.5M is a 0.5 m passive copper direct-attach cable with QSFP28 connectors at both ends. It provides a short-reach, high-bandwidth physical link between QSFP28 ports in switches, routers and servers without requiring separate optical transceivers. The cable is intended for dense data centre top-of-rack, server-to-switch and switch-to-switch connections where minimal latency and low power use are important. Its fixed-length, compact design simplifies cabling in rack environments while supporting 100 Gigabit Ethernet and other QSFP28-compatible interfaces.

Advantages

The passive copper construction delivers low latency and avoids the need for powered transceivers, reducing overall link power consumption. A 0.5 m length minimizes signal loss and crosstalk on very short interconnects while keeping cable slack to a minimum in congested racks. QSFP28 connectors at both ends ensure direct compatibility with devices that support QSFP28 ports and standard DAC operation, enabling plug-and-play installation without additional modules. The compact profile helps maintain airflow and cable management in dense installations.

Suitable for

• Top-of-rack connections between switches and server leafs in data centres
• Short-range interconnects in server racks and network closets
• High-speed links where low latency and low power are required
• Direct connections between QSFP28 ports for 100 Gigabit Ethernet or compatible high-speed fabrics

Key specifications

• Connector type: QSFP28 to QSFP28
• Cable type: Passive copper direct-attach cable (DAC)
• Length: 0.5 m
• Supported data rates: QSFP28-class speeds (100 Gb/s and compatible lane configurations)
• Typical use: Short-reach rack-level and chassis-level interconnects
• Power: Passive (no active electronics in the cable)

How to use

Install the QSFP28-DAC-0.5M by inserting each QSFP28 connector into the corresponding QSFP28 port on the devices to be connected. Ensure both devices are powered down or follow the vendor’s hot-plug guidance when connecting live equipment. Verify link status and configuration on the connected devices; the cable functions as a direct electrical link and does not require separate transceivers or additional configuration beyond standard port settings. Route the cable to avoid sharp bends and reduce mechanical strain at the connectors.

Recommendations

Use this 0.5 m passive DAC for intra-rack and adjacent-rack connections where port-to-port distances are short. Avoid using passive DACs for runs beyond the tested short-reach distance; for longer links, consider active DACs or optical transceivers and fibre cables. Follow equipment vendor compatibility lists and ensure QSFP28 port settings match the required speed and lane configuration.