QSFP Direct Attach Cable BlueOptics LSWM1QSTK0 40GBASE-CR4, 1 m, passive

BlueOptics QSFP Direct Attach Cable LSWM1QSTK0 40GBASE-CR4 is a 1 m passive copper DAC designed for 40 Gbps four-lane Ethernet connections. The cable uses a QSFP form-factor to provide a direct attach link between switches, servers or routers supporting 40GBASE-CR4, enabling short-reach, low-latency interconnects in data center racks and network closets. It is intended for environments that require cost-efficient and power-conscious 40 Gb/s point-to-point links without the need for additional optical transceivers.

Advantages

The passive copper design delivers low latency and low power consumption compared with active modules, while maintaining full four-lane 40 Gbps bandwidth. The QSFP form-factor ensures compatibility with QSFP ports commonly found on networking equipment, allowing plug-and-play installation without complex configuration. At 1 meter length the cable is suited for short interconnects inside racks or between adjacent racks, offering a reliable and cost-effective alternative to optical links for short distances.

Suitable for

• Short-reach interconnects between switches within a rack
• Direct connections from servers to top-of-rack switches
• High-density aggregation links in data center environments
• Low-latency links for clustering or storage networks

Key specifications

• Interface: QSFP (quad small form-factor pluggable) direct attach cable
• Data rate: 40 Gbps (4 lanes, 10 Gbps per lane)
• Standard: 40GBASE-CR4
• Length: 1 meter
• Cable type: Passive copper DAC
• Typical use case: Short-reach, within-rack or adjacent-rack connections

How to use

Insert each QSFP connector into the corresponding QSFP port on the two devices to be connected, ensuring proper orientation and a secure seating. No special configuration or external power is required for passive operation; the devices will negotiate link parameters according to the 40GBASE-CR4 standard. Verify link status on both devices after insertion and route the cable to avoid sharp bends or excessive tension.

Usage recommendations

For reliable performance, use the cable for distances up to its specified length in within-rack or adjacent-rack deployments. Avoid tight cable bends (respect the minimum bend radius), keep the cable away from sources of electromagnetic interference, and confirm QSFP port compatibility and firmware support on network equipment prior to installation.