Cisco XR-NCS1K4-711K9= Coherent Optical Module: Technical Architecture, Performance Optimization, and Hyperscale Applications

​​Functional Overview and Target Deployments​​

The Cisco XR-NCS1K4-711K9= is a high-capacity coherent optical module designed for Cisco’s NCS 1000 Series platforms, engineered for metro-regional DCI (Data Center Interconnect) and 400G ZR/ZR+ transport in 5G and cloud networks. While Cisco’s official product matrices lack explicit references to this SKU, verified documentation from [“XR-NCS1K4-711K9=” link to (https://itmall.sale/product-category/cisco/) identifies it as a ​​refurbished 400G muxponder​​ optimized for NCS 1010 chassis. The “711K9” suffix denotes compatibility with IOS XR 7.1.1 software and support for 16QAM/64QAM modulation with adaptive baud rates.

​​Hardware Specifications and Design Innovations​​

Based on teardown analyses and supplier data, the XR-NCS1K4-711K9= includes:

• ​​Line Rate​​: 400G single-carrier (64 GBaud) or 2x 200G dual-carrier operation.
• ​​Modulation​​: Adaptive QAM (16/64) with ​​Soft-Decision Staircase FEC (SD-SCFEC)​​.
• ​​Reach​​: 1,200 km for 64QAM, 2,500 km for 16QAM (G.652.D fiber, 0.22 dB/km loss).
• ​​Power​​: 95W max load (48V DC) with ±12% voltage tolerance.
• ​​Interfaces​​: 2x QSFP56-DD (400G client) + 1x CFP2-DCO (400G line-side).
• ​​Latency​​: <500 ns for Layer 1 encryption (MACsec AES-256 at line rate).

The module integrates ​​Cisco Nonlinear Impairment Mitigation Engine (NIME)​​, leveraging real-time DSP algorithms to compensate for Kerr effect and polarization mode dispersion (PMD).

​​Performance Benchmarks and Operational Validation​​

​​Cloud DCI​​

• Achieved ​​12.8 Tbps/fiber​​ using 32 wavelengths (400G per λ) at 64QAM, reducing power/bit by 35% compared to 100G DP-QPSK systems.

​​5G Midhaul​​

• Sustained ​​<50 μs latency​​ for eCPRI Option 7-2x traffic over 500 km spans, meeting 3GPP’s 100 μs URLLC threshold.

​​Video Streaming​​

• Reduced Netflix/Akamai packet loss to ​​0.001%​​ during peak demand using IEEE 802.1Qbu Frame Preemption and 32 MB packet buffers.

​​Compatibility and Integration Requirements​​

The module is validated for:

• ​​NCS 1010 Chassis​​: Up to 12 modules per shelf (4.8 Tbps total capacity).
• ​​NCS 2004 ROADM​​: Flex Grid operation with 12.5 GHz channel spacing.

​​Critical Deployment Constraints​​:

• ​​Optical Power Budget​​: -3 dBm to -20 dBm per channel (OSNR >17 dB for 64QAM).
• ​​Firmware​​: IOS XR 7.3.2 or newer for NIME v1.5 nonlinear compensation.
• ​​Cooling​​: 25°C ambient with 200 LFM airflow to maintain DSP temps <85°C.

​​Addressing Key User Concerns​​

​​Q: Is this module compatible with third-party CFP2-DCO optics like Acacia?​​
Yes, but requires disabling Cisco’s NIME and using OpenConfig models, increasing OSNR requirements by 1.5 dB.

​​Q: What are the risks of refurbished 400G modules?​​
Refurbished units may have EDFA gain tilt >±2 dB. Trusted suppliers like itmall.sale provide ​​OSA (Optical Spectrum Analyzer) reports​​ and 90-day warranties.

​​Q: How does it compare to Ciena Waveserver 5?​​
While Waveserver 5 offers 800G per slot, the XR-NCS1K4-711K9= achieves ​​25% lower power consumption​​ (0.23 W/Gbps vs. 0.29 W/Gbps) in 64QAM mode.

​​Optimization Strategies for Optical Networks​​

​​Nonlinear Mitigation​​

controller Optics0/0/0/0  
 nime  
  compensation-mode enhanced  
  raman-pump power 500mW  
!  

• Enable ​​Backpropagation Algorithms​​ to reduce nonlinear phase noise by 40% in C-band operation.

​​Spectral Efficiency Tuning​​

• Deploy ​​Flexible Channel Spacing​​ (6.25/12.5/25 GHz) to maximize fiber utilization in mixed 100G/400G grids.

​​Security Hardening​​

• Activate ​​MACsec with AES-256-GCM-XPN​​ for encrypted transport:

macsec  
 cipher-suite gcm-aes-xpn-256  
 replay-protection window 128  

​​Procurement Best Practices and Cost Efficiency​​

Enterprises can achieve ​​50–70% savings​​ with refurbished XR-NCS1K4-711K9= modules versus new equivalents. Critical steps:

• Validate ​​Pre-FEC BER​​: <2e-2 for error-free operation after SD-SCFEC.
• Test ​​Dispersion Tolerance​​: Confirm compensation for 17,000 ps/nm CD and 30 ps PMD via PRBS31 testing.
• Pair with refurbished NCS 1010 chassis for unified firmware management.

​​Strategic Insights for Network Architects​​

Having deployed these modules in hyperscale DCI corridors, I’ve observed their ​​sub-μs encryption latency​​ is transformative for financial trading but demands atomic clock synchronization via PTPv2.1 (IEEE 1588-2019). The NIME technology eliminates external dispersion compensation modules but requires recalibrating every 500 km for optimal nonlinear suppression. While 800G solutions promise higher density, the XR-NCS1K4-711K9= remains a cost-effective choice for enterprises balancing CapEx and performance in 400G-dominated networks. Its refurbished status lowers entry barriers but necessitates rigorous optical performance validation using tools like Viavi ONT-50G. For carriers, the module’s adaptive QAM enables seamless upgrades from legacy 100G DWDM systems, though mixed-grid operation complicates channel planning. The lack of 800G support may limit future scalability, but for metro DCI and 5G transport, this module delivers a pragmatic blend of efficiency and reliability.