Pricing and Unresponsive Flows Purging for Global Rate Enhancement

Pricing-based Active Queue Management (AQM), such as Random Exponential Marking (REM), outperforms other probabilistic counterpart techniques, like Random Early Detection (RED), in terms of both high utilization and negligible loss and delay. However, the pricing-based protocols do not take account of unresponsive flows that can significantly alter the subsequent rate allocation. This letter presents Purge (Pricing and Un-Responsive flows purging for Global rate Enhancement) that extends the REM framework to regulate unresponsive flows. We show that Purge is effective at providing fairness and requires small memory and low-complexity operations.

Active Queue Management

Although powerful and necessary to prevent network collapse, the congestion control mechanism of the TCP is not sufficient to avoid congestion. Since TCP sources exert a limited control of the network, and unresponsive flows, which do not slow down their sending rates when congestion occurs, may be present, the efficacy of end-to-end congestion control also relies on queue mechanisms at the routers.