Routing-Aware Shaping for Feasible Multi-Domain Determinism
Andrea Francini, Raymond Miller, Bruce Cilli, Catello Di Martino · 2024
Use cases for network determinism may involve the traversal of multiple network domains. A typical example is the edge-cloud virtualization of the controllers for industrial automation, where the end-to-end data path may include a private mobile network and a wired local-area network within the factory premises, a public transport network between the factory and the edge-cloud data center, and a switching fabric within the same data center. Maintaining deterministic guarantees throughout these domains, likely operated by different providers, is a daunting task when each domain relies on its own control and data-plane technologies for satisfaction of its allocated portion of the end-to-end requirements. We propose a universal model for determinism in wired packet networks that simplifies the realization of deterministic services over chains of network domains. The model builds on a novel traffic shaper where routing information constrains the packet scheduling decisions. The shaper, and therefore the provisioning of resources for every deterministic service, is only needed at the ingress edge of each wired domain. We conjecture perdomain latency bounds enforced by the shaper and corroborate them with experimental evidence. The bounds are easy to combine for multi-domain network paths.