CAB-L240-10-N-R= Cisco Cable: What Does It Do, Compatibility, and Deployment Best Practices

​​Overview of the CAB-L240-10-N-R=​​

The ​​CAB-L240-10-N-R=​​ is a ​​Cisco proprietary cable​​ designed for high-density, high-speed connectivity in enterprise and data center environments. This 10-meter shielded cable supports ​​low-latency, high-bandwidth applications​​, making it ideal for linking switches, routers, and storage systems in demanding setups.

​​Technical Specifications​​

• ​​Cable Type:​​ ​​Direct Attach Copper (DAC)​​ with ruggedized shielding for EMI protection.
• ​​Data Rate:​​ Optimized for ​​40Gbps/100Gbps​​ Ethernet (QSFP28/QSFP+ interfaces).
• ​​Length:​​ 10 meters, balancing reach and signal integrity for mid-range deployments.
• ​​Connectors:​​ ​​Cisco-specific QSFP ends​​ for seamless integration with Nexus and Catalyst series hardware.

​​Key User Concerns Addressed​​

​​Q: Which Cisco devices is this cable compatible with?​​

• ​​Switches:​​ Nexus 9300/9500, Catalyst 9400, and other QSFP28-enabled platforms.
• ​​Routers:​​ ASR 9900 series for high-capacity backbone links.

​​Q: Can it replace optical transceivers?​​
Yes—​​passive DACs like the CAB-L240-10-N-R=​​ offer ​​lower cost​​ and ​​simpler deployment​​ than fiber optics for distances under 15 meters. However, fiber remains superior for longer runs (>100m).

​​Primary Use Cases​​

• ​​Data Center Spine-Leaf Topologies:​​ Connect spine switches to leaf layers within the same rack row.
• ​​Storage Area Networks (SANs):​​ High-throughput links between storage arrays and switches.
• ​​Disaster Recovery Sites:​​ Redundant connections for synchronous data replication.

​​Advantages Over Generic Cables​​

• ​​Reliability:​​ Cisco’s rigorous testing ensures ​​99.999% uptime​​ in mission-critical environments.
• ​​Compliance:​​ Meets ​​IEEE 802.3bj​​ standards for 40G/100G Ethernet.
• ​​Durability:​​ Reinforced jacket resists abrasion in congested cable trays.

For pricing and availability, visit the “CAB-L240-10-N-R=” product listing.

​​Field-Tested Perspective​​

In large-scale data center upgrades, I’ve relied on cables like the CAB-L240-10-N-R= to minimize latency bottlenecks between core switches. While third-party DACs might save initial costs, they often lack Cisco’s end-to-end compatibility guarantees—a critical factor when troubleshooting intermittent link drops. If your budget allows, stick with OEM cables for high-stakes segments. Always validate length requirements to avoid signal degradation.