Network Cable BlueOptics Q28-4S28-DAC-2M-PS-BL QSFP28 4 x SFP28 InfiniBand 2m Black

The BlueOptics Q28-4S28-DAC-2M-PS-BL is a 2 meter passive direct attach cable (DAC) with a QSFP28 connector on one end and four SFP28 connectors on the other, designed for short-distance high-speed connections in racks and between adjacent racks. This twinax copper breakout cable supports 100GBase-CR4 and 4x25GBASE-CR electrical transmission formats and is suitable for InfiniBand, Ethernet and Fibre Channel/FCoE environments when used with hardware that supports passive DACs. The cable is supplied in black and has a compact, male-to-male form factor for secure rack-mounted connections.

Advantages

The cable provides a cost-efficient, low-latency physical link for high-throughput server, switch and storage interconnects. As a passive twinax solution, it consumes minimal power and requires no active electronics, which reduces potential points of failure and simplifies compatibility with systems that support MSA-compliant QSFP28 breakout DACs. Constructed from quality components and meeting MSA electrical and mechanical definitions, it offers predictable performance for short-range links and an expected long service life when used within specified environments.

Suitable for

• Short-range rack-to-rack and within-rack connections in data centers
• 100GBase-CR4 and 4x25GBASE-CR breakout links between QSFP28 ports and SFP28 ports
• High-throughput server, switch and storage interconnects supporting InfiniBand, Ethernet or FCoE/Fibre Channel over DAC
• Environments that require low-latency, low-power physical connectivity

Key specifications

• Cable type: Passive twinax copper direct attach cable (DAC)
• Connector A: QSFP28 (breakout end)
• Connector B: 4 × SFP28 (individual breakout connectors)
• Supported protocols: 100GBase-CR4; 4×25GBASE-CR; compatible with InfiniBand, Ethernet, FCoE/Fibre Channel when supported by host hardware
• Length: 2 m
• Wire gauge: 26 AWG
• Colour: Black
• Weight: approximately 0.25 kg
• Compliance: MSA-compatible QSFP28 breakout DAC electrical and mechanical definitions

How to use

Install the BlueOptics QSFP28 to 4×SFP28 DAC by aligning and inserting the QSFP28 end into a compatible QSFP28 port and the four SFP28 ends into the corresponding SFP28 ports on the target devices. Ensure both devices officially support passive DAC breakout cables and the selected transmission mode (100GBase-CR4 or 4×25G). Handle the cable by the connectors and avoid sharp bends; maintain the minimum bend radius specified by the device vendors. After physical installation, verify link status through the host equipment management interface and check that the negotiated link speeds match the intended protocol.

Recommendations

Use this passive DAC for short, direct connections inside racks or between adjacent racks where 2 m reach is sufficient. Confirm compatibility with your switch, router or storage vendor for passive QSFP28 breakout cables and, if available, request a test sample to validate interoperability before deploying at scale.