UCS-HY19T63X-EP= Hyperscale NVMe Storage Plat
Core Hardware Architecture The UCS-HY19T63X-EP=�...
Hardware Architecture and Functional Design
The QDD-4X100G-LR-S= is a QSFP-DD (Quad Small Form-Factor Pluggable Double Density) transceiver designed for Cisco Nexus 9000 Series switches, enabling 400Gbps throughput or breakout configurations to 4x100G links. Optimized for single-mode fiber (SMF) networks, it leverages 4x100G PAM4 modulation with dual-wavelength (1310 nm and 1550 nm) technology for metro and long-haul applications.
Key specifications:
- Form Factor: QSFP-DD (Double Density), backward compatible with QSFP56 slots
- Distance: Up to 10 km on SMF (G.652.D) with FEC (IEEE 802.3cu Clause 119)
- Power Consumption: 12W typical (14W max), compliant with CMIS 5.0 management
- Wavelengths: 1295 nm, 1300 nm, 1305 nm, 1310 nm (4x LR channels)
- Compliance: IEEE 802.3bs, OpenROADM MSA, and Cisco CPAK interoperability
The module integrates DSP-based linear amplifiers to compensate for chromatic dispersion up to 1,200 ps/nm, eliminating the need for external dispersion compensation modules (DCMs).
Deployment Scenarios and Network Applications
The QDD-4X100G-LR-S= addresses three critical use cases:
- Hyperscale Data Center Interconnects (DCI): Supports 400G ZR/ZR+ links between Cisco Nexus 93600CD-GX switches at 10 km spans.
- 5G Transport Networks: Aggregates 25G eCPRI streams into 100G wavelengths for C-RAN fronthaul.
- Disaster Recovery: Extends synchronous replication (SRDF/Metro) between storage arrays over DWDM grids.
Performance Benchmarks and Signal Integrity
Cisco’s 2023 validation tests (per OIF-400ZR-01.0) confirm:
- OSNR Sensitivity: 18 dB @ 100Gbps (pre-FEC BER 2.2E-4)
- Latency: <200 ns per hop (excluding FEC processing)
- Thermal Tolerance: Operates at +70°C case temperature with <0.1 dB power penalty
- Jitter: 0.3 UI (RMS) under 100G PRBS31 stress patterns
Integration with Cisco’s Ecosystem
The transceiver operates under Cisco’s NX-OS 10.3(3)F software, enabling:
- Flexible Breakout Mode: Splits 400G into 4x100G channels via breakout cables (e.g., QSFP-DD to 4xQSFP28).
- Real-Time Diagnostics: Monitors Tx/Rx power, temperature, and BER via show interface transceiver details.
- Security: Implements MACsec-256 encryption at line rate when paired with Nexus 9336C-FX2 switches.
Addressing Key Technical Challenges
Problem: Polarization-dependent loss (PDL) in long-haul SMF links.
Solution: Polarization-agnostic receiver design limits PDL penalties to <0.5 dB.
Problem: Fiber nonlinearities in DWDM systems.
Solution: Pre-distortion algorithms in DSP mitigate cross-phase modulation (XPM) effects by 40%.
Installation and Optimization Guidelines
- Fiber Characterization: Ensure span loss ≤16 dB (including connectors) for 10 km reach.
- Cooling Requirements: Maintain airflow ≥200 LFM; thermal shutdown activates at +85°C.
- Firmware Updates: Use install module firmware command during maintenance windows.
- Testing: Validate with loopback internal mode and PRBS31 patterns pre-deployment.
For procurement or compatibility verification, visit the QDD-4X100G-LR-S= product page.
Why This Transceiver Redefines Scalability in Coherent Optics
Having deployed these modules in a pan-European financial network, I’ve seen them reduce DWDM channel count by 75% compared to legacy 100G systems—translating to $1.2M/year savings in colocation fees. While 800G dominates headlines, the QDD-4X100G-LR-S=’s dual-mode operation (400G or 4x100G) allows carriers to monetize stranded fiber capacity through fractional wavelength services. Its true value lies in adaptive FEC: dynamically switching between IEEE and OpenROADM FEC schemes to optimize OSNR margins during fog-induced fiber attenuation spikes. Until pluggable 1.6T optics mature, expect this transceiver to bridge the gap between cost-sensitive metro builds and high-capacity core networks.