To advance data plane performance of the open-source SCION border router, we are developing a zero-copy AF_XDP-based underlay. AF_XDP is a Linux technology for high-speed networking applications, available since Linux kernel version 4.18. It will enable our border router to achieve a substantial performance uplift over the existing UDP/IP Linux networking stack-based implementation.

To support this work, we built a dedicated bare-metal 25 Gbit/s testbench workstation for development and benchmarking, with funding provided by the NLnet Foundation. The system combines a workstation-class Intel Xeon W-series platform with three NVIDIA/Mellanox BlueField-2 dual-port 25 Gbit/s network cards.

For a detailed technical breakdown – including hardware selection rationale, configuration, thermal design, pitfalls encountered, and full benchmark results – see the full article on
GitHub.