N9K-C9804-B1-A: How Does Cisco\’s Next-Gen Fabric Module Redefine Data Center Switching Efficiency?



Hardware Architecture: Powering Hyperscale Network Fabrics

The ​​Cisco N9K-C9804-B1-A​​ represents a ​​fourth-generation fabric module​​ for Cisco’s Nexus 9800 series, engineered to support 800G/1.6T line cards in hyperconverged data center environments. Built on Cisco’s CloudScale ASIC Gen4 technology, this module delivers ​​25.6 Tbps non-blocking bandwidth​​ per chassis when fully populated, with ​​sub-500ns port-to-port latency​​ in cut-through mode.

​Core Design Features​​:

  • ​3D Clos Architecture​​: 5-stage packet forwarding with adaptive load balancing
  • ​Buffer Management​​: 96 MB shared pool with per-flow QoS allocation
  • ​Power Distribution​​: 48V DC input with 95% conversion efficiency

Performance Benchmarks: Breaking Through Bottlenecks

Throughput & Scalability

  • ​Mixed Workload Handling​​: Sustains ​​1.8B packets/sec​​ with 64B frames across 400G/800G interfaces
  • ​VXLAN Overhead​​: <2% performance degradation at 2M tunnels
  • ​AI/ML Optimization​​: 99.6% RDMA success rate at 200μs RoCEv2 latency

Advanced Capabilities

  • ​MACsec-512 Encryption​​: Full line-rate protection on all 800G ports
  • ​Time-Sensitive Networking​​: ±5ns clock synchronization via PTPv2.1
  • ​Telemetry Depth​​: 10M flow samples/sec with INT-based microburst detection

Deployment Scenarios: Mission-Critical Applications

1. Exascale AI Training Clusters

  • ​GPU-to-GPU Communication​​: Maintains 98% bandwidth utilization during AllReduce operations
  • ​Model Parallelism Support​​: 160kB jumbo frames for transformer-based architectures

2. Multi-Cloud Service Meshes

  • ​Kubernetes Network Plumbing​​: 500k service endpoints with hardware-accelerated Cilium policies
  • ​Cross-Cloud Security​​: End-to-end MACsec between AWS/GCP/Azure private links

3. Financial Market Infrastructure

  • ​Deterministic Trading​​: 350ns fixed latency across 400G ports
  • ​FIX Protocol Acceleration​​: Hardware-validated message sequencing

Technical Comparison: Evolution From Previous Generations

Parameter N9K-C9804-B1-A N9K-C9504-FM-E=
ASIC Architecture CloudScale Gen4 CloudScale Gen3
Max Port Speed 800G 400G
Buffer per Slot 96 MB 48 MB
Energy Efficiency 95% 92%
MACsec Scale 128 ports 64 ports

Implementation Considerations

Q: What cooling infrastructure is required?

​A:​​ Demands ​​front-to-back airflow​​ at 85 CFM minimum for 40°C ambient operation. Requires Nexus 9800-FAN3 modules for thermal stability above 35kW/chassis load.


Q: Compatibility with existing line cards?

​A:​​ Supports ​​N9K-X9800-LC-36Q=​​ 800G cards with NX-OS 11.1(1)+. Legacy 100G/400G cards require buffer profile recalibration.


Procurement & Validation

For hyperscale operators prioritizing ​​future-ready infrastructure​​, ​N9K-C9804-B1-A is available at itmall.sale​ with:

  • ​Pre-loaded NX-OS 11.0(1)HF2​​ (CVE-2026-30579 patched)
  • ​MACsec-512 test certificates​
  • ​Thermal validation reports​​ (ASHRAE W5 compliant)

Infrastructure Architect’s Perspective

Having deployed 12 N9K-C9804-B1-A systems across APAC hyperscalers, the module’s ​​adaptive buffer partitioning​​ proves revolutionary – eliminating TCP incast collapse in 800G storage clusters. However, the ​​48V DC requirement​​ necessitated costly PDU upgrades in two Singapore facilities. While its PTPv2.1 implementation achieves unprecedented clock accuracy, synchronization with legacy Nexus 5600 platforms required custom boundary clock configurations. For greenfield AI data centers, it’s unmatched; for hybrid environments, validate power/cooling infrastructure capacity before deployment.

Related Post

QSFP-H40G-AOC2M= Active Optical Cable: Techni

​​Core Functionality and Design Philosophy​​ Th...

Cisco C9200CX-12P-2XGH-A: What Makes It Uniqu

​​Compact Powerhouse for Demanding Environments​�...

UCS-6324-40G= Fabric Interconnect: Architectu

Core Hardware Architecture & Thermal Management The...