New Scale-Up Networking Collaboration Announced at OCP Global Summit
October 13, 2025 – Today, the Open Compute Project Foundation (OCP), a nonprofit international organization that brings at-scale innovations and hyperscale best practices to all, announced plans for a new OCP Networking Project workstream: Ethernet for Scale-Up Networking (ESUN). This effort is launching after the OCP Global Summit 2025, themed “Leading the future of AI” where the OCP Community comes together to share the work in designing high-performance, large-scale data center infrastructure with a continued focus on Open Systems for AI.
With the initiation of this workstream by AMD, Arista, ARM, Broadcom, Cisco, HPE Networking, Marvell, Meta, Microsoft, NVIDIA, OpenAI and Oracle, the OCP Community now has the opportunity to work on areas that address scale-up connectivity across accelerated AI infrastructure. The scale-up domain in XPU-based systems can be viewed in two primary areas: 1) network functionality, and 2) XPU-endpoint functionality.
First, the network aspect of scale-up focuses on how traffic is sent out across the network switches themselves, including protocol headers, error handling, and lossless data transfer. This is what ESUN intends to address and what the planned OCP workstream by the same name will focus on. The workstream itself is planned to kick off shortly after the OCP Global Summit.
Second, in the XPU-endpoint domain, the design depends on factors such as workload partitioning, memory ordering, and load balancing, and it is often tightly co-designed with the XPU architecture itself. OCP has previously launched an effort to advance the endpoint functionality for scale-up networking through the SUE-Transport (Scale-up Ethernet Transport) workstream (originally named SUE, it has been renamed and clarified as SUE-T in contrast to ESUN). SUE-T will carry forward some of the SUE work which was seeded with the Broadcom contribution of the version 1.0 specification.
What is ESUN?
ESUN is a new workstream collaboration designed as an open technical forum to advance Ethernet in the rapidly growing scale-up domain for AI systems. This initiative brings together operators and leading vendors to collaborate on leveraging and adapting Ethernet for the unique demands of scale-up networking.
Key Focus Areas:
- Technical Collaboration: ESUN serves as an open forum where operators, equipment and component manufacturers can jointly advance Ethernet solutions optimized for scale-up networking.
- Interoperability: The initiative emphasizes development and interoperability of XPU network interfaces and Ethernet switch ASICs for scale-up.
- Technical Focus: Initial focus will be on L2/L3 Ethernet framing and switching, enabling robust, lossless, and error-resilient single-hop and multi-hop topologies.
- Standards Alignment: ESUN will actively engage with organizations such as UEC (Ultra-Ethernet Consortium) and IEEE 802.3 (Ethernet) to align with open standards, incorporate best practices, and accelerate innovation.
- Ecosystem Enablement: By leveraging Ethernet’s mature hardware and software ecosystem, ESUN will encourage diverse implementations and drive rapid adoption across the industry.
What is out of scope for ESUN?
ESUN focuses solely on open, standards-based Ethernet switching and framing for scale-up networking—excluding host-side stacks, non-Ethernet protocols, application-layer solutions, and proprietary technologies.
Initial Companies
We thank the initial group of OCP members who have started the ESUN effort:
- AMD
- Arista
- ARM
- Broadcom
- Cisco
- HPE Networking
- Marvell
- Meta
- Microsoft
- Nvidia
- OpenAI
- Oracle
We invite all interested parties to join us, helping to shape the future of scale-up networking!
Join the Conversation
As usual at OCP, ESUN’s workstream will host regular, open meetings for all interested parties. Whether you’re representing an operator, vendor, or standards body, your participation is welcome as we shape the future of scale-up networking together.
Look for the official announcement in the OCP Global Summit opening keynote by OCP leadership. Let’s build the next generation of open, scalable, and interoperable networking for AI and beyond!
For more details and to get involved, watch the OCP Networking Project’s mailing list and calendar. In the meantime, please join the upcoming sessions at the OCP Global Summit 2025.