POSTER: FlexUP Breaking Up the CU-UP to Speed Up the RAN

The Centralized Unit User Plane (CU-UP) in 5G networks works as an aggregation point of the RAN, facing increasing performance demands yet commonly limited by general-purpose processors. In this work, we present FlexUP, an architecture that offloads CU-UP functions to programmable switches and SmartNICs via a three-path abstraction: fast, medium, and slow. By matching function complexity to the appropriate hardware, FlexUP can improve latency, throughput, and resource efficiency while aligning with the modular and disaggregated principles of Open RAN (O-RAN).