DAC cable CBO QSFP28-DAC-3M 3 m passive copper for QSFP28 ports

CBO QSFP28-DAC-3M is a 3-metre passive copper Direct Attach Cable engineered for QSFP28 ports to support short-reach 100GbE links. The fixed-attached twin-ended design provides a simple, low-latency physical connection between compatible switches, routers and network adapters without the need for separate transceivers. Intended for data centre top-of-rack and server interconnects, this cable delivers a compact, low-power alternative to active optical modules for distances up to 3 metres.

Advantages

The passive copper construction offers minimal latency and consistent signal integrity for short-distance connections. Being a Direct Attach Cable means easy installation with no additional optics or transceivers required, reducing component count and simplifying inventory. The 3 m length balances reach and cable management needs in rack environments while consuming no additional power compared with active solutions, making it suitable for dense deployments where energy efficiency and predictable performance are important.

Suitable for

• Top-of-rack switch-to-switch 100GbE connections
• Server-to-switch interconnects in data centres
• High-performance computing clusters requiring short low-latency links
• Patch panels or direct port-to-port connections within the same rack or adjacent racks

Key specifications

• Interface type: QSFP28 to QSFP28
• Cable type: Passive copper Direct Attach Cable (DAC)
• Data rate support: 100 Gigabit Ethernet (100GbE)
• Length: 3 metres
• Latency: very low, cable-implemented direct connection
• Typical use environment: short-reach, rack-level data centre links

How to use

Insert each QSFP28 connector into the corresponding QSFP28 port on the network devices until the latch engages. Confirm that both devices recognize the link through their management interfaces or LED indicators. For reliable operation, route the cable to avoid sharp bends and mechanical strain and secure it according to rack management practices. If necessary, power-cycle or reconfigure port settings to ensure link negotiation completes successfully.

Usage recommendations

Use this passive 3 m DAC for short, direct 100GbE connections inside racks or between adjacent racks. Avoid exceeding the recommended bend radius and protect connectors from dust when not in use. For longer distances or when optical isolation is required, consider active optical transceivers instead.