Application Scenarios and End Customers of 400G Optical Modules

🚀 Introduction

Internet companies and cloud service providers (CSPs) are upgrading their data center network infrastructure from 100G to 400G to meet higher bandwidth demands and lower latency requirements.

400G optical modules are being deployed to power next-generation high-performance networks across cloud, AI, 5G, and enterprise use cases.

🏢 1. Core Switching & Data Center Interconnect (DCI)

  • Primary application of 400G modules is in core data center switching.
  • Enables high-speed, low-latency communication across racks and between data centers.
  • Critical for spine-leaf architectures and multi-site data center interconnects.

☁️ 2. Cloud Computing and AI Clusters

  • AI/ML training workloads require high-speed interconnects, especially for GPU-to-GPU communication.
  • Examples include NVIDIA DGX and Google TPU clusters.
  • 400G supports massive bandwidth needs and ultra-low latency in AI training environments.
  • Drives scalable, efficient AI cluster deployment.

📡 3. 5G Transport Networks

  • 400G optical modules are being used in both front-haul and back-haul of 5G networks.
  • Supports high-density traffic aggregation and low-latency delivery across metro and core transport layers.
  • Ensures smooth 5G experience in urban and dense-use environments.

💻 4. High-Performance Computing (HPC)

  • Supercomputing centers require ultra-fast, low-latency interconnects for:
    • Scientific research
    • Financial modeling (e.g., HFT)
    • Genomic sequencing & analysis
  • 400G modules power high-throughput HPC clusters to handle massive computational loads.

🏢 5. Enterprise Data Centers and Cloud Switching

  • Enterprises are modernizing network infrastructure to support:
    • Cloud storage access
    • Remote/hybrid work connectivity
    • Big data & analytics platforms
  • 400G ensures scalable bandwidth and future-proof performance.

🧑‍💻 6. Who’s Using 400G? – End Customers

☁️ Cloud & Internet Companies

  • AWS (Amazon Web Services)
  • Microsoft Azure
  • Google Cloud
  • Meta (Facebook)
  • Tencent Cloud, Alibaba Cloud, Huawei Cloud, Baidu Cloud

📡 Telecom Operators

  • AT&T, Verizon, Orange, BT
  • China Mobile, China Unicom, China Telecom
  • NTT Docomo, KDDI, SoftBank (Japan)
  • SK Telecom, KT (South Korea), and more

🧠 AI Computing Companies

  • NVIDIA (GPU clusters)
  • Google (TPU clusters)
  • OpenAI, Meta AI, and other research institutions

💼 Financial & Research Institutions

  • Goldman Sachs, Morgan Stanley
  • Harvard, MIT, BGI Genomics
  • Supercomputing centers (e.g., Tianhe, Oak Ridge National Lab)

🛠 Network Equipment Vendors

  • Cisco, Arista, Juniper Networks
  • Huawei, ZTE, Nokia, and others

🔮 7. Looking Ahead: Toward 800G and Beyond

  • 400G optical modules are primarily used in high-speed, low-latency, and high-throughput networking environments.
  • As the industry evolves toward 800G and 1.6T, 400G adoption is expected to continue growing steadily.
  • Ideal as a bridge technology for scalable, next-gen infrastructure.