HiP4-UPF: Towards High-Performance Comprehensive 5G User Plane Function on P4 Programmable Switches

Due to better cost benefits, P4 programmable switches have been considered in a few recent works to implement 5G User Plane Function (UPF). To circumvent limited resources on P4 programmable switches, they either ignore some essential UPF features or resort to a hybrid deployment approach which requires extra resources. This work is aimed to improve the performance of UPFs with comprehensive features which, except packet buffering, are deployable entirely on commodity P4 programmable switches. We build a baseline UPF based on prior work and analyze its key performance bottlenecks. We propose a three-tiered approach to optimize rule storage on the switch ASICs. We also develop a novel scheme that combines pendulum table access and selective usage pulling to reduce the operational latency of the UPF. Using a commodity P4 programmable switch, the experimental results show that our UPF implementation can support twice as many mobile devices as the baseline UPF and 1.9 times more than SD-Fabric. Our work also improves the throughputs in three common types of 5G call flows by 9-619% over the UPF solutions in two open-source 5G network emulators.