C9120AXI-E: How Does Cisco’s Indoor Wi-Fi 6
Architecture and Key Hardware Features The ...
Product Overview and Design Objectives
The Cisco NXA-QDD-2Q-CU1M= is a QSFP-DD (Quad Small Form-Factor Pluggable Double Density) passive direct-attach copper (DAC) cable designed for high-density 400G/800G interconnects in modern data centers. Optimized for Nexus 9000 Series switches like the 9336C-FX2 and 93600CD-GX, this 1-meter cable enables cost-effective, low-latency connectivity between leaf-spine tiers or adjacent racks. Key design goals include:
- Density Maximization: Supports 36x400G ports per 1RU in Nexus 9336C-FX2 chassis via QSFP-DD-to-QSFP-DD configurations.
- Power Efficiency: Consumes 0.1W per port (vs. 1.5W for active optical cables), reducing annual cooling costs by $120/rack.
- Backward Compatibility: Works with QSFP28 (100G) and QSFP56 (200G) ports using breakout adapters, preserving legacy infrastructure investments.
The cable complies with IEEE 802.3bs and QSFP-DD MSA standards, ensuring interoperability in multi-vendor environments.
Technical Specifications and Performance Validation
Cisco’s 2024 Data Center Cabling Guide confirms the following metrics:
- Data Rate: 2x200G (400G aggregate) via PAM4 modulation and 50 Gbaud signaling.
- Insertion Loss: <16 dB at 26.56 GHz, verified through TDR (Time-Domain Reflectometry) testing.
- Crosstalk Isolation: >40 dB between adjacent pairs, minimizing BER (Bit Error Rate) to <1E-15.
- Durability: Rated for 10,000 insertion cycles with reinforced connectors and strain relief boots.
In lab tests, the cable sustained 400Gbps line rate with <0.5 ns/m latency across 10,000 hours of continuous operation.
Key Use Cases and Deployment Scenarios
1. AI/ML Cluster Interconnects
A hyperscaler deployed 5,000 cables in Nexus 93600CD-GX switches to connect NVIDIA DGX A100 systems, achieving 3.2 Tbps bisectional bandwidth per rack. The passive design eliminated optical transceiver costs, saving $2.1M per 10-rack cluster.
2. High-Frequency Trading (HFT) Backbones
A Tokyo stock exchange used the cables to link Arista 7800R3 and Cisco Nexus 9336C-FX2 switches, achieving 98 ns end-to-end latency for market data distribution—40% lower than active optical solutions.
3. Cloud Storage Fabrics
A European MSP reduced SAN replication times by 70% using 400G SRv6-based storage over IP, leveraging the cable’s lossless Ethernet capabilities with Cisco Nexus Dashboard flow analytics.
Addressing Critical Deployment Concerns
Q: How does it compare to active optical cables (AOCs) for 400G?
While AOCs support longer distances (up to 100m), the NXA-QDD-2Q-CU1M= offers:
- Cost Savings: 80% lower upfront cost per port.
- Power Efficiency: 0.1W vs. 1.5W per port.
- Latency: 0.5 ns/m vs. 3 ns/m for AOCs.
Q: What’s the maximum operational temperature?
The cable operates at 0°C to 70°C with 85% non-condensing humidity. For hotter environments, Cisco recommends NXA-QDD-2Q-AOC3M= active optical cables.
Q: Can it be used with non-Cisco switches?
Yes, but full Forward Error Correction (FEC) requires switches supporting IEEE 802.3bj Clause 91. Compatibility with Arista 7060X2 and Juniper QFX5220 has been validated.
Installation and Maintenance Best Practices
- Bend Radius Management: Maintain ≥30 mm bend radius to prevent signal degradation.
- Connector Care: Use Cisco CMP-2Q-CLEANER every 6 months to remove dust from QSFP-DD receptacles.
- Labeling: Apply Cisco CAB-LBL-400G flags to identify breakout configurations (e.g., 8x50G vs. 4x100G).
- Testing: Validate link integrity with Cisco NX-OS CLI commands:
show interface ethernet 1/1 transceiver details show interface ethernet 1/1 counters errors
For enterprises migrating from QSFP28 DACs, Cisco offers trade-in credits covering 20% of costs under its Cabling Modernization Program.
Why Enterprises Choose This Solution
- Density: Enables 144x400G ports in a 4RU Nexus 93600CD-GX chassis—3x the density of QSFP-56 solutions.
- Compliance: Meets RoHS 3, REACH SVHC, and TAA standards for global deployments.
- Future-Proofing: Supports 800G upgrades via firmware-enabled PAM4-to-NRZ retimer modes.
For pricing and bulk orders, visit the Cisco NXA-QDD-2Q-CU1M= product page at ITMall.sale.
Lessons from Hyperscale Deployments
Analyzing field data from 15+ hyperscalers reveals two operational truths:
- Cable Management Is Critical: A cloud provider reduced unplanned outages by 60% after implementing Cisco’s Vertical Exhaust Rack (VER) design, which eliminated cable stress in overhead trays.
- Heat Kills Predictably: A blockchain firm experienced BER spikes in cables routed near hot aisle containment barriers. Relocating cables ≥6 inches from heat sources restored signal integrity.
While optical evangelists tout fiber’s supremacy, the NXA-QDD-2Q-CU1M= proves copper’s relevance in the 400G/800G era. For enterprises prioritizing cost, latency, and sustainability, this cable isn’t just a component—it’s the connective tissue of next-gen AI and cloud architectures. In an industry where every picosecond and watt counts, its value proposition remains unmatched.