UltraEthernet: The Future Fabric for AI & HPC Data Centers

Introduction: The New Age of AI & HPC Networking

Modern Data centers power a new era of computing. From Large Language Models (LLMs) to exascale scientific simulations, Artificial Intelligence (AI) and High-Performance Computing (HPC) workloads demand massive scale, ultra-low latency, and lossless communication across thousands of GPUs and accelerators.

Traditional Ethernet and even classic HPC interconnects (InfiniBand) are being stretched beyond their design limits. The result? Network congestion, unpredictable latency, and inefficiencies that throttle cluster performance directly impacting training time, inference responsiveness, and operating costs.

Enter UltraEthernet, a next-generation open Ethernet fabric defined by the Ultra Ethernet Consortium (UEC) designed from the ground up to support AI/HPC-class networks with the openness, interoperability, and scalability that modern Data centers require.

Current Landscape: Challenges with Traditional Networking

Requirements of AI & HPC Workloads

AI clusters and HPC systems are unique in their networking needs:

• Ultra-low latency communication between GPUs and accelerators
• Lossless transport for collective broadcast and AllReduce operations
• Congestion-aware flow control at extreme scales
• Efficient hardware offload to reduce CPU burden

Where Traditional Networks Limits

Traditional Ethernet, while ubiquitous, suffers from:

• Packet loss and unpredictable latency under congestion
• Heavy reliance on PFC (Priority Flow Control) leading to head-of-line blocking and deadlocks
• Limited support for AI-specific collectives and transport semantics
• Poor visibility and tiny telemetry for real-time congestion control

Even InfiniBand, while powerful, is often closed-ecosystem, vendor-centric and expensive, limiting widespread adoption outside elite HPC environments.

UltraEthernet: What It Is & Why It Matters

UltraEthernet is Ethernet reimagined for AI/HPC at scale. At its core is Ultra Ethernet Transport (UET), a layered and optimized transport abstraction engineered for:

• Lossless scaling without PFC
• Flow-aware forwarding
• Built-in congestion feedback and telemetry
• Retry-based loss recovery in hardware

UET introduces a protocol stack comprising layered headers such as UET → SES → PDS → Payload, enabling smarter transport features while maintaining Ethernet compatibility.

UltraEthernet vs. Legacy Fabrics

UltraEthernet bridges the gap between Ethernet’s openness and InfiniBand’s performance. It brings:

• Open, multi-vendor interoperability
• Cost-efficient deployment on standard Data center optics and cabling
• AI-native transport semantics missing in traditional Ethernet
• Competitive performance vs. proprietary fabrics

In essence:

UltraEthernet = Ethernet + AI/HPC Acceleration + Lossless Scaling + Open Ecosystem

This positions UltraEthernet as the future standard interconnect for Cloud providers, Hyperscalers, and Enterprise Data centers adopting AI workloads at scale.

SmartNICs & UET: Offloading Intelligence to the Edge

To unlock UltraEthernet’s potential, the control and transport logic must be offloaded from servers to programmable SmartNICs.

Why SmartNICs Matter

SmartNICs act as programmable offload engines that:

• Parse UET headers at line rate
• Maintain stateful retry logic
• Insert congestion telemetry (ECN/INT)
• Manage session state and reorder buffers
• Perform DMA offload with Libfabric integration
• Facilitate RDMA-like GPU-to-GPU transport over UET

FPGA based SmartNICs: A Perfect Fit

FPGA based SmartNIC’s architecture excels as a UET offload platform because it combines:

• P4-programmable data plane for flexible protocol parsing
• Onboard Arm cores for control-plane logic and stateful engines
• High bandwidth, low jitter, and telemetry capabilities

UET Functionality	FPGA based SmartNICs Feasibility
UET Header Parsing	✅ P4 Pipeline
FlowID/Opcode Handling	✅ Stateful Match/Action
Retry Logic	✅ Stateful + ARM Offload
INT Metadata Insertion	✅ Telemetry Block
Packet Trimming/Reordering	✅ P4 + Deparser
Host RAM + NIC Metadata	Integrated

Benefits of UET Offload on FPGA based SmartNICs

• Reduces CPU overhead by migrating retry, telemetry, and flow logic to the NIC
• Enables lossless training networks without PFC
• Positions FPGA based SmartNICs + VVDN as UET-ready SmartNIC solution
• Differentiates SmartNIC + VVDN stack vs. traditional Broadcom-centric NICs

Business Value: Performance, Cost & Interoperability

UltraEthernet delivers measurable value across three critical dimensions:

Performance

• Microsecond-class latency at scale
• Lossless transports without PFC complexity
• Better collective performance for AI training
• Line-rate forwarding with hardware retry and congestion feedback

Cost

• Uses standard Ethernet optics and cabling
• Avoids expensive proprietary fabrics
• Reduces infrastructure complexity and operating expenses
• Offloads networking work freeing CPU cycles for applications

Interoperability

• Open multi-vendor ecosystem
• Compatibility with existing Ethernet infrastructure
• Roadmap for broad support across NICs, switches and management stacks

Where VVDN Fits In

At VVDN, we understand the architectural evolution of AI Data center fabrics. Our work spans:

• Design and integration of AI/HPC-class networks
• UET offload development for programmable SmartNICs
• Integration of UET with FPGA based SmartNICs and Libfabric ecosystems
• Enabling CUDA/OpenMPI-friendly transports across UET fabrics

VVDN’s deep experience in advanced protocol offloads, silicon integration and Data center networking positions us as an ideal partner for OEMs, Hyperscalers and Data center Services Providers adopting UltraEthernet at scale.

Conclusion: The Road Ahead

UltraEthernet represents a paradigm shift blending Ethernet’s openness with AI/HPC performance requirements. With UET providing lossless, scalable and programmable networking, Data centers can finally host AI workloads with predictable performance, lower operational cost and multi-vendor flexibility.

As UltraEthernet adoption grows, programmable FPGA based SmartNICs will play a central role in driving performance and telemetry into the data plane. With strategic partners like VVDN, organizations can future-proof their infrastructure and unlock the full potential of AI/HPC networking.

Contact us for live demo at info@vvdntech.com