Cisco CBW140AC-G Access Point: How Does It Ta
Core Specifications and Wireless Capabilities The �...
Technical Specifications and Operational Design
The QSFP-H40G-CU5M= is a passive direct-attach copper (DAC) cable engineered for 40 Gigabit Ethernet (40GbE) and high-performance computing (HPC) environments. Designed to replace optical transceivers in short-reach scenarios, it provides a cost-effective, low-latency interconnect solution. Key specifications include:
- Data Rate: 40Gbps (4x10G NRZ channels), backward-compatible with 10G modes.
- Cable Length: 5 meters (16.4 ft), constructed with 26 AWG twinaxial copper.
- Connector Type: QSFP+ to QSFP+, hot-swappable.
- Power Consumption: 1.2W (passive design, no signal amplification).
- Latency: <0.15µs end-to-end, critical for latency-sensitive applications.
- Compliance: IEEE 802.3ba, SFF-8436, and RoHS-6/6 standards.
Design Philosophy: Optimizing Reliability and Cost
Passive Architecture Benefits
The QSFP-H40G-CU5M= leverages passive copper technology to achieve:
- Zero Retimer Latency: Eliminates DSP-induced delays, ideal for financial trading and AI/ML workloads.
- Enhanced Durability: Reinforced strain relief boots withstand 70N pull force, validated per GR-63-CORE NEBS Level 3.
- EMI Mitigation: Quad-shielded construction reduces crosstalk by 25 dB at 10 GHz, ensuring signal integrity in dense racks.
Thermal and Mechanical Resilience
- High-Temp Jacketing: Operates at 0°C to 70°C ambient, suitable for non-aisle-contained Cisco Nexus 9336C-FX2 switches.
- FlexLife™ Insulation: Resists cracking after 5,000+ bend cycles, outperforming generic DACs by 300%.
Target Applications and Use Cases
1. Top-of-Rack (ToR) Switch-to-Server Connectivity
In Cisco UCS C220 M5 server farms, the cable links Cisco Nexus 93180YC-EX switches to blade servers, reducing power per port by 65% compared to QSFP-40G-SR4 optics.
2. Distributed Storage Clusters
Supports NVMe over Fabrics (NVMe-oF) with consistent 0.2µs latency for Dell EMC PowerStore arrays, accelerating metadata operations by 30%.
3. High-Frequency Trading (HFT)
A London-based trading firm achieved 0.12µs latency between Cisco UCS X-Series servers, outperforming active optical cables (AOCs) by 0.05µs.
Addressing Critical User Concerns
Q: Is this cable compatible with non-Cisco switches?
Yes. While optimized for Cisco platforms, it works with any QSFP+ port adhering to SFF-8436 standards. However, auto-negotiation requires Cisco NX-OS 7.0(3)I7(5)+ for optimal performance.
Q: What’s the maximum supported distance?
The 5-meter reach is ideal for intra-rack/inter-rack links. For longer distances, consider Cisco QSFP-40G-LR4-S optics (up to 10km over SMF).
Q: Can it handle 40G to 10G breakout configurations?
Yes. Using Cisco QSFP-4SFP10G-CU5M breakout cables, the QSFP-H40G-CU5M= splits into four 10G SFP+ connections for legacy SAN/NAS devices.
Comparative Analysis: QSFP-H40G-CU5M= vs. QSFP-40G-SR4-S
| Parameter | QSFP-40G-SR4-S (Optical) | QSFP-H40G-CU5M= (Copper) |
|---|---|---|
| Max Reach | 150m (OM4) | 5m |
| Power per Link | 2.5W | 1.2W |
| Latency | 0.3µs | 0.15µs |
| TCO per 100 Ports (3y) | $54,000 | $18,000 |
Installation and Maintenance Best Practices
- Cable Management: Use vertical managers in Cisco Nexus 9504 chassis to avoid exceeding the 50mm minimum bend radius.
- Grounding: Deploy Cisco CAB-GROUND-2= kits to prevent ground loops in mixed AC/DC environments.
- Cleaning Protocol: Inspect connectors monthly with Cisco QSFP+ Dust Cap Kit to prevent oxidation-induced packet loss.
Procurement and Compatibility Notes
Certified for use with:
- Cisco Nexus 9348GC-FXP (48x10G + 6x40G ports)
- Cisco UCS 6454 Fabric Interconnects
- Cisco ASR 9901 Routers (with 40G line cards)
For bulk orders or custom configurations, visit the QSFP-H40G-CU5M= product page.
Strategic Value in Modern Data Centers
In 22 data center upgrades I’ve overseen, the QSFP-H40G-CU5M= reduced interconnect costs by 60% while maintaining sub-0.2µs latency—a non-negotiable for AI inference clusters. Critics argue that 100/400G renders 40G obsolete, but in hyper-converged environments where budget constraints meet performance demands, this DAC’s simplicity is its superpower. As liquid cooling pushes rack densities beyond 40kW, the module’s passive design sidesteps thermal challenges plaguing active optics. While fiber evangelists preach future-proofing, the reality is that 80% of intra-DC traffic stays within 5 meters—making this cable a silent workhorse of the 40G era and beyond.