高速イーサネットAI

Ultra Ethernet Stack 1.0: A Game Changer, But Proper Assurance is Key

By :

Ultra-Ethernet-Stack-A-Game-Changer-blog-hero-1240x600

The UEC Stack will mark a major evolution in Ethernet, integrating scalability, low latency, and congestion control for AI and HPC data centers. However, traditional testing won’t be enough. Learn why new assurance models, multi-KPI validation, and real-world traffic modeling will be essential for success—and what effective testing strategies involve.

Significant leap forward in networking

The Ultra Ethernet Consortium (UEC) is a leading industry group comprising over 80 member companies and more than 800 active participants. Its primary objective is to evolve Ethernet and associated technologies into a coherent, efficient standard tailored for AI and HPC data centers.

Classic Ethernet is enhanced with additional protocols such as RoCEv2 and DCQCN, incorporating congestion control algorithms to achieve lossless transport and low-latency performance—critical for HPC and, more specifically, AI fabrics.

However, classic Ethernet does not inherently provide these guarantees, necessitating the use of auxiliary stacks and algorithms. The UEC aims to integrate and evolve these capabilities into Ethernet itself, representing a significant leap forward in networking.

The first tangible deliverable from the UEC is the Ultra Ethernet Stack 1.0 specification, which significantly enhances traditional Ethernet by offering:

  • Scalability to 1M+ endpoints

  • Improved network utilization and multipathing

  • Lower tail latency

  • Flexible packet ordering

  • Faster congestion control response times

  • Modernized and optimized RDMA

  • Security at the foundation

  • Compute offload for in-network collectives

  • End-to-end telemetry for enhanced visibility

The UEC Stack is both ambitious and revolutionary, representing a paradigm shift in networking and network operations. It can be a game changer for Ethernet in East West network.

Need for a new assurance model

With such a fundamental evolution in Ethernet, traditional testing and assurance methodologies must also evolve. Relying on legacy testing approaches will lead to under-testing and an increased risk of false positives.

For example, in classic Ethernet, performance evaluation focuses on packet loss, bandwidth, and latency using accumulated counter metrics. However, in the UEC model, we must also incorporate:

  • Connection attributes (e.g., multipath and flexible sequencing)

  • Per-service QoS policies

In traditional Ethernet performance testing, the primary pass/fail metric is typically throughput. However, as AI fabrics require lossless transmission, strict sequencing, and ultra-low latency, the definition of pass/fail must evolve. A more effective approach is to establish a multi-KPI framework where failure in any individual metric results in a failed test iteration. Consequently, to pass, all performance metrics must meet their respective thresholds concurrently, ensuring a comprehensive measure of test success.

The future of traffic generation and benchmarking

Traffic generation methodologies must also adapt. If test traffic does not accurately replicate real-world RDMA streams, including interleaving patterns and microbursts, the likelihood of test failure increases.

Moreover, traditional benchmarking standards such as RFC 2544, RFC 2889, and Y.1564 will become increasingly obsolete. These benchmarks are too primitive to effectively evaluate UEC Stack-based networks. In fact, the very concept of standardized benchmarks may lead to misleading results, as no generic benchmark can accurately reflect the unique characteristics of real-world networks.

A far more effective strategy involves:

  1. Understanding the specific characteristics of your network

  2. Modeling real-world traffic patterns accurately

  3. Measuring performance based on real-use conditions

UEC Stack and future technologies

The UEC Stack will also drive the next generation of Ethernet technologies, such as 1.6T Ethernet. AI and HPC workloads leveraging UEC Stack support will likely become the primary drivers for faster Ethernet advancements.

Scalability is another key design goal. However, true scalability is impossible without robust QoS mechanisms. To ensure scalability, we must:

  • Define clear per-service QoS policies as pass/fail criteria

  • Accurately model interleaved transmission patterns

  • Ensure predictability and survivability under peak loads

  • Verify protocol correctness at every packet level

The UEC Stack 1.0 is an exciting and bold evolution of Ethernet. However, realizing its full potential requires a shift in testing methodologies. By implementing multi-KPI pass/fail policies, considering real-world traffic patterns, and moving beyond outdated benchmarking standards, we can effectively validate the UEC Stack and unlock its transformative power in modern networking.

Explore innovative testing approaches for validating the AI Ethernet fabric.

For more information, watch thought leader perspectives captured at the Ethernet Alliance’s recent TEF “Ethernet in the Age of AI” Forum on the evolution needed in Ethernet to support AI/ML workloads.

コンテンツはいかがでしたか?

こちらで当社のブログをご購読ください。

ブログニュースレターの購読

Chris Chapman

Senior Methodologist, Spirent

With over 20 years in Telecommunications and 11+ years of network performance theory, Chris has extensive knowledge in testing and deployment of L1-7 network systems. His expertise includes performance analysis of QoS, QoE, TCP, IP (v4 and v6), UDP, QoE, HTTP(S), FTP, WAN acceleration, BGP, OSPF, IS-IS. MPLS, LDP, RSVP, VPLS, firewalls and load balancers. His specialties are centered on testing L1-7.