Flow Queue PIE: A Hybrid Packet Scheduler and Active Queue Management Algorithm

This document presents Flow Queue Proportional Integral controller Enhanced (FQ-PIE), a hybrid packet scheduler and Active Queue Management (AQM) algorithm to isolate flows and tackle the problem of bufferbloat. FQ-PIE uses hashing to classify incoming packets into different queues and provide flow isolation. Packets are dequeued by using a variant of the round robin scheduler. Each such flow is managed by the PIE algorithm to maintain high link utilization while controlling the queue delay to a target value.