Experimental Evaluation of DetNet PREOF Mechanisms on Programmable Data Planes
5G and 6G systems increasingly rely on ultra-lowlatency and highly reliable communications to support timecritical applications at the network edge. While deterministic communication has emerged as a key requirement in domains such as industrial automation, smart grids, and automotive systems, yet remains challenging over packet-switched networks. Determinism entails delivering packets either at precise time instants (in-time) or within strict bounded delays (on-time), imposing stringent constraints on latency, jitter, and reliability. The Deterministic Networking (DetNet) architecture, standardized by the IETF, seeks to provide such guarantees at Layer 3; however, fully open, end-to-end implementations of its core mechanisms are still lacking. The main contributions of the paper are: (1) a new opensource implementation of DetNet, (2) validation of its functionality, (3) experimental evaluation aimed at analyzing the benefits and challenges of the technology, and (4) all the aforementioned contributions developed in compliance with current standardization efforts. Our design leverages P4-programmable Tofino switches in combination with CPU-based packet processing using the DPDK to assess the feasibility and effectiveness of implementing DetNet PREOF mechanisms in programmable data planes (PDP). Results show near-zero packet loss below the MTU, and zero out-of-order delivery across all configurations, underscoring the value of programmable data planes for validating deterministic networking mechanisms.