Open Source Summit Korea 2026

Running the 5G User Plane Function (UPF) as a Kubernetes pod using open-source stacks like free5GC often hits a wall: kernel networking overhead destroys packet throughput. eBPF can bypass this bottleneck, but the concept remains intimidating to network engineers who don’t do kernel programming.

This lightning talk provides a zero-to-understanding educational journey. The speaker will first illustrate, with simple diagrams, the kernel’s slow path versus the eBPF XDP/AF_XDP fast path for GTP-U packets. Then, using a live (or pre-recorded) demo on a Minikube cluster, they will show an open-source UPF accelerated by a small eBPF program—demonstrating how GTP encapsulation/decapsulation is handled in the driver, with line-rate forwarding. The entire code, including a ready-to-run Docker image and Helm chart, will be shared on GitHub. Attendees will leave with a mental model of exactly where eBPF sits, which hooks to use, and how to evaluate eBPF acceleration for their own 5G cloud-native network functions. No prior eBPF or 5G core knowledge is required ,only curiosity about high-performance networking.