Towards a Partial Credit-Based Shaper Deployment Algorithm in Time-Sensitive Networks

The Credit-Based Shaper (CBS) enforces bandwidth control of high-priority traffic, thereby improving fairness by reducing delays for medium and low priorities. However, CBS can introduce latency for high priorities, especially when multiple crossed CBS are involved. To address this challenge in time-sensitive networks, we introduce a partial CBS deployment approach, wherein CBS is implemented only in selected nodes in the network. This approach aims to minimize as much as possible latency degradation for high priorities, while guaranteeing deadlines for medium and low priority flows. Additionally, this approach offers cost, complexity and legacy interoperability advantages over the full deployment of CBS. Through a motivational example, we highlight the need for an adequate approach to select the placement and configuration of CBS. Finally, we discuss the problem formulation as an optimization problem, and provide insights for appropriate solution methods.