DAC cable CBO CBL-QSFP-40GE-PASS-2M 2m Passive QSFP+ to QSFP+ 40GbE direct-attach

CBO CBL-QSFP-40GE-PASS-2M is a 2‑metre passive DAC (direct-attach copper) cable with QSFP+ connectors that supports 40GbE links. It is intended for short-reach connections between servers, switches and storage devices where a direct copper connection minimizes latency and power consumption. The cable is a factory-terminated solution that eliminates the need for separate optical transceivers, simplifying rack-level cabling for top-of-rack and aggregation deployments.

Advantages

The passive QSFP+ to QSFP+ assembly offers low electrical latency and minimal power draw compared with active optics or transceiver-based links. Its 2 m length provides a predictable signal path suitable for intra-rack and short inter-rack connections. As a direct-attach copper solution it reduces component count and total cost of ownership for high-density 40GbE environments, while maintaining compatibility with standard QSFP+ ports and link speeds.

Suitable for

• Short-range server-to-switch connections within racks
• Top-of-rack and aggregation switch interconnects
• High-density switch-to-switch links in data centres
• Storage array connections requiring 40GbE bandwidth

Key specifications

• Cable type: passive direct-attach copper (DAC)
• Connector type: QSFP+ to QSFP+
• Nominal data rate: 40 Gigabit Ethernet (40GbE)
• Length: 2 metres
• Typical use range: short-reach, intra-rack and close inter-rack
• Power profile: passive (no active electronics in cable)

How to use

Insert each QSFP+ plug into the corresponding QSFP+ port on the two devices to be connected, ensuring the latch engages and the module is fully seated. Verify link negotiation on both endpoints and confirm 40GbE operation via device management interfaces. Handle the cable by its connectors and avoid sharp bends; maintain the specified bend radius and secure excess cable to prevent strain on the plugs. If the link does not come up, check port configuration and compatibility with passive DAC modules on the equipment.

Recommendations

Use this 2 m passive DAC for short-distance connections where low latency and low power consumption are priorities. Avoid using passive copper assemblies for distances beyond the recommended intra-rack and nearby inter-rack ranges; for longer runs, consider active DACs or optical transceivers with fiber cabling. Ensure device port compatibility with passive QSFP+ cables and consult switch vendor documentation for any required settings or supported cable lists.