SynAVB: Route and Slope Synthesis Ensuring Guaranteed Service in Ethernet AVB

In the automotive domain, Ethernet Audio Video Bridging (AVB) provides service guarantees for real-time traffic. Its configuration synthesis requires routing the flows and allocating the bandwidth for Credit Based Shaping (CBS). Current approaches typically employ deadline-oblivious bandwidth allocation and rely on routing to establish deadline guarantees. But the worst-case delay of AVB flows requires complex analysis. Thus, routing integrated with the delay analysis either supports limited Stream Reservation (SR) classes or suffers significant timing overhead. To enable efficient run-time flow setup, we propose SynAVB, a tool to synthesize the configuration of Ethernet AVB, which establishes deadline awareness in bandwidth allocation. SynAVB supports an arbitrary number of SR classes and processes them one by one. For the flows in an SR class, it first performs a deadline-oblivious routing based on Mixed Integer Linear Programming (MILP) to guarantee the necessary bandwidth required by the flows. Then, a deadline-aware slope allocation algorithm computes the bandwidth required on every link to satisfy the deadline of all flows. Our experiment demonstrates that, given the same routes, the deadline-aware bandwidth allocation results in fewer flows violating the deadline compared with other allocation strategies. Moreover, SynAVB can guarantee the deadline of more flows while its run-time is up to 14.3x faster than the state-of-the-art approaches.