Technical Report Number
Fair Queuing (FQ) algorithms provide isolation between packet flows, allowing max-min fair sharing of a link even when flows misbehave. However, fairness comes at the expense of per-flow state. To keep the memory requirement independent of the flow count, the router can isolate aggregates of flows, rather than individual flows. We investigate the feasibility of protecting individual flows under such aggregate isolation in the context of Multiple Queue Fair Queuing (MQFQ), where the router maintains a fixed number of queues and associates multiple queues with each flow. MQFQ places packets in the shortest queue associated with their flow. The redundancy of multiple queues allows a flow to transmit at a fair rate even when one of its queues is congested. However, a misbehaving flow is able to acquire a larger than fair share of the bottleneck link capacity. We also discuss important implementation issues such as avoidance of packet reordering.
Georg, Manfred; Jechlitschek, Christopher; and Gorinsky, Sergey, "Improving Individual Flow Performance with Multiple Queue Fair Queuing" Report Number: WUCSE-2007-30 (2007). All Computer Science and Engineering Research.