Direct Attach Copper (DAC) Cable CBO Q28-4S28-DAC-3M-BC-BL, QSFP28, 3 m, BlueLAN

The BlueOptics Direct Attach Copper (DAC) Cable CBO Q28-4S28-DAC-3M-BC-BL is a 3 m QSFP28 passive copper cable designed for short-reach 100 Gigabit Ethernet interconnects. This fixed-link assembly provides a direct electrical connection between QSFP28 ports on switches, routers and servers, offering low latency and deterministic performance for rack-to-rack and intra-rack deployments in data centres. The cable is finished in blue sheathing and terminated with QSFP28 plugs to match standard high-density networking equipment.

Advantages

The DAC cable delivers a cost-efficient and power-saving alternative to active optical transceivers for short distances. Its passive construction eliminates the need for separate transceivers and reduces heat generation and power consumption in dense switch environments. The QSFP28 interface supports 100GbE links while maintaining a reliable electrical transmission with minimal signal processing, simplifying installation and reducing the number of field-replaceable components.

Suitable for

• High-density switch-to-switch 100GbE connections within racks and between adjacent racks
• Server uplinks and top-of-rack (ToR) aggregation in data centres
• Short-reach interconnects in storage and compute clusters requiring low latency

Key specifications

• Connector type: QSFP28 to QSFP28
• Cable length: 3 metres
• Data rate: supports 100 Gigabit Ethernet (100GbE)
• Cable media: direct attach copper (passive copper assembly)
• Colour: blue outer sheath
• Typical use: short-reach, rack-level interconnects

How to use

Install by plugging each QSFP28 connector into the corresponding QSFP28 port on your networking equipment. Ensure both ports are powered down or that hot-plug procedures recommended by the equipment vendor are followed. Verify link status through the switch or server management interface after insertion. For best performance, avoid tight bends and strain near the connectors and retain any built-in locking clips to secure the connection.

Usage recommendations

Use this passive QSFP28 DAC cable for short-distance 100GbE links where power efficiency and low latency are priorities. For runs beyond typical rack-to-rack distances or when optical isolation is required, consider optical transceivers and fibre cabling instead.