Traffic Pattern Re-Arrangement by Hierarchical Calendar Queueing-Based Packet Scheduler

Communication traffic patterns, representing network and application behavior, are beneficial for the transport and application layers to estimate the states of black-box network systems. Masking noisy traffic features helps high-quality communication by reducing the misestimation of network states due to unstable delay behavior for delay-sensitive applications. Motivated by the effects, we propose TrafficArranger, a traffic pattern re-arrangement system using packet scheduling to provide a target quality of service (QoS), including throughput, delay, and packet interval, as required by each flow. The main component of TrafficArranger is Hierarchical Calendar Queueing (HCQ) for delay-based packet scheduling. We introduce a number of techniques: (i) stepped dequeue to control the dequeue level for flexible jitter control for improving robustness to traffic load while keeping control accuracy and (ii) rush dequeue and reenqueue skipping to address out-of-order issues in HCQ. Through performance comparison with some leaves of Linux qdisc and state-of-the-art HCQ method, i.e., Gearbox, only TrafficArranger controls QoS as required for all QoS classes (i.e., throughput, delay, and packet interval). Also, we demonstrate that TrafficArranger effectively works for performance stabilization in a cooperative adaptive cruise control system.