Incremental Routing and Scheduling Using Multipath and Nonzero Jitter Bound for IEEE 802.1 Qbv Time Aware Shaper

Abstract

IEEE 802.1 Qbv time-aware shaper (TAS) has been developed for delivery of time-critical periodic frames of time-triggered (TT) flows over Ethernet under strict end-to-end latency and jitter bounds. Efficient routing and flow scheduling are critical for successful deployments of TAS systems. Although many routing and flow scheduling schemes have been proposed so far, most of them are restricted to single path routing and zero jitter delivery. Although multipath routing and nonzero jitter bound could provide more flexibility in scheduling thus increase scheduling success, they have been rarely studied in TAS scheduling. In this work, online incremental routing and scheduling schemes utilizing multipath routing and nonzero jitter bound are proposed based on no-wait packet switching mechanism for TAS. Two schemes are proposed, i.e., incremental single path routing and scheduling (ISPRS) and incremental multipath routing and scheduling (IMPRS), each with nonzero jitter bound. The proposed schemes are based on resource-centric scheduling approach in which information on feasible free time-slices in the paths for a TT flow is updated according to flow scheduling result and used for scheduling of next flow. Numerical results show that scheduling with nonzero jitter bound or multipath routing could improve schedule failure rates compared with single path scheduling with zero jitter bound. Scheduling with nonzero jitter bound could improve schedule failure rates in most of considered cases, while the cases of multipath routing more favorable are relatively limited.INDEX TERMS Jitter, multipath routing, QoS, real-time Ethernet, scheduling, time-aware shaper, timesensitive network. 802.1Qbv.