6GUPF: A DPU-based Programmable User Plane Function for Enhanced Flow-based QoS

Traditional 5G user plane function (UPF) architectures are software-based implementations that struggle to maintain performance. To meet the stringent quality of service (QoS) and scalability requirements of 5G under high session and data plane loads, a highly efficient next-generation UPF is required. In this paper, we present a next-generation 6GUPF that fully leverages the hardware acceleration of SmartNICs/DPUs. The 6GUPF is developed using DOCA Flow API, which enables fast, programmable packet processing directly in the data path, specifically for the N3 gNB network and N6 interfaces of datanet. The architecture integrates flow-based acceleration for stateful flow tracking and symmetric Receive Side Scaling (RSS) to utilize cores and manage non-blocking states efficiently. This will help minimize latency and avoid contention in multi-core environments. Our experiments show that hardware-offloaded UPF achieves an aggregate line rate of 400 Gbit/s, supports 1 million concurrent data streams, and scales up to 500,000 active User Equipment (UE) instances while maintaining QoS and session isolation. It also enables 40% lower latency compared to traditional software UPFs. Unlike Tofino-based P4 switch UPF designs, which are limited by SRAM and TCAM constraints when storing large-scale data streams, our DPU-based solution is ideal for high-density Protocol Data Unit (PDU) deployments without sacrificing programmability and performance. It creates a path for cloud-native, 6G UPF deployments that can scale to a wide range of workloads, from ultra-low-latency applications to large-scale IoT backhaul.