Calnex Solutions Achieves PFC Transparent 400G Network Emulation for Validation Testing of Lossless Ethernet AI Clusters

EDINBURGH, Scotland, April 15, 2026 /PRNewswire/ -- Calnex Solutions plc (LON: CLX) today announced a significant advancement in network emulation for AI infrastructure, demonstrating 400G Ethernet validation at full line rate with 100 percent throughput while allowing Priority Flow Control (PFC) frames to pass through transparently. The capability enables engineers to test and optimize lossless Ethernet fabrics, including long-haul DCI links using PFC, under controlled and repeatable impairment conditions in the lab. By introducing congestion and delay without intercepting control traffic, the solution preserves the behavior and semantics of lossless Ethernet.

Network behavior is a critical determinant of efficiency in large scale AI clusters. Microbursts, congestion and PFC interactions introduce bottlenecks that increase tail latency, directly impacting GPU utilization and job completion time. These conditions are difficult to reproduce consistently in lab environments, making it challenging for engineering teams to validate how lossless Ethernet fabrics will perform under real production workloads. Calnex addresses this by enabling controlled, repeatable validation of these behaviors, bringing real-world network conditions into the lab.

"AI infrastructure investment is accelerating rapidly, but return on that investment still depends heavily on the network," said Tommy Cook, CEO & Founder at Calnex Solutions. "In large-scale distributed compute environments such as training clusters, network inefficiencies can leave a significant share of GPU capacity underutilized. Our breakthrough is the ability to recreate these conditions at full throughput while preserving the native behavior of lossless Ethernet, helping engineering teams test performance and reduce deployment risk."

This milestone reinforces Calnex's growing role in AI validation, supporting customers across inference, AI-RAN and data center networking. As AI deployments expand across different environments, Calnex is focused on enabling testing and assurance solutions that help teams deliver predictable performance.

For more information, please contact Lee Noble at Lee.Noble@calnexsol.com 

Calnex designs, produces and markets test instrumentation and solutions for network synchronization and network emulation, enabling its customers to validate the performance of the critical infrastructure associated with telecoms networks.

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