DAC cable CBO Q28-4S28-DAC-3M 3 m QSFP28 to QSFP28 Twinax Direct Attach Copper

CBO Q28-4S28-DAC-3M is a 3 m Direct Attach Copper (DAC) twinax cable with QSFP28 connectors on both ends, intended for short-reach, high-speed interconnects in data center environments. The cable provides a cost-effective, low-latency way to connect QSFP28 ports for 100 Gigabit Ethernet links where optical transceivers are not required. Its fixed-length twinax design delivers consistent electrical performance and simplified installation for within-rack and adjacent-rack connections.

Advantages

The DAC cable offers low power consumption and minimal latency compared with active optical solutions, while maintaining signal integrity for short distances. As a passive twinax assembly with QSFP28 connectors, it reduces component count and simplifies port provisioning. The robust copper conductors and molded connector housings provide reliable mechanical stability for frequent plug-and-play use in dense rack deployments.

Suitable for

• Switch-to-switch connections in the same rack or adjacent racks
• Switch-to-server links using QSFP28 ports
• High-performance computing clusters requiring short-reach 100GbE interconnects
• Top-of-rack (ToR) and within-rack cabling where optics are not necessary

Key specifications

• Connector type: QSFP28 to QSFP28
• Cable type: Twinax Direct Attach Copper (DAC)
• Length: 3 metres
• Supported data rate: up to 100 Gb/s per link (QSFP28)
• Application: short-reach, within-rack and adjacent-rack interconnects
• Latency: low, passive copper electrical link

How to use

Install the cable by inserting each QSFP28 connector into the corresponding QSFP28 port until the latch engages. Ensure that both devices support passive DAC cables at the intended data rate and that ports are configured for 100GbE operation. Route the cable to avoid sharp bends and mechanical strain; maintain the manufacturer’s minimum bend radius. For removal, disengage the connector latch and pull straight out to avoid damaging the port or cable.

Recommendations

Use this 3 m twinax DAC for short-distance links inside racks or between adjacent racks. Verify compatibility with your network equipment’s QSFP28 ports and firmware, and follow cable routing best practices to preserve signal integrity and mechanical lifespan.