DAC cable CBO QSFP28-DAC-2M 2m passive copper QSFP28 to QSFP28

The BlueOptics DAC cable CBO QSFP28-DAC-2M is a 2 metre passive copper direct attach cable that connects two QSFP28 ports for short-reach interconnects. Designed for use in data centre racks and network equipment, this QSFP28-to-QSFP28 cable supports 100 Gigabit Ethernet links without active signal conversion. The passive construction provides low latency and predictable electrical performance for QSFP28-capable switches, routers and servers where a short, cost-effective copper connection is suitable.

Advantages

This passive QSFP28 DAC cable delivers a compact, energy-efficient link with minimal insertion loss and low propagation delay. The fixed 2 m length simplifies cable management in dense rack environments and eliminates the need for transceivers, reducing both power consumption and total hardware cost. Compatibility with standard QSFP28 ports ensures straightforward installation and reliable operation for short-distance connections.

Suitable for

• Short-reach interconnects between QSFP28 ports in data centre racks
• Direct connections between switches, routers and servers supporting QSFP28
• Top-of-rack and end-of-row patching where passive copper is acceptable
• High-density deployments requiring compact, low-latency cabling

Key specifications

• Connector type: QSFP28 to QSFP28
• Cable type: Passive twinax copper
• Nominal length: 2 metres
• Supported data rate: 100 Gbps (QSFP28)
• Form factor: Direct attach cable (DAC)
• Typical use: Short-reach intra-rack and adjacent-rack links

How to use

Plug the QSFP28 connectors into the corresponding QSFP28 ports on each device until the latch engages. Ensure devices are powered down or that hot‑plugging is supported by your equipment before insertion or removal to prevent port damage. Verify link status on connected devices and confirm negotiation to the expected 100 Gbps mode. For best signal integrity, avoid sharp bends and keep the cable routed to minimise stress on the connectors.

Recommendations

Use this 2 m passive QSFP28 DAC for intra-rack and short adjacent-rack links where a low-cost, low-latency copper connection is acceptable; for longer distances or when optical isolation is required, choose active cables or optical transceivers and fibre cabling instead.