Receiver-Based Flow Control for Networks in Overload

TL;DR

This paper introduces a receiver-based flow control method with threshold-based packet dropping that maximizes utility in overloaded networks without source flow control, using virtual queues and back-pressure routing.

Contribution

It presents a novel receiver-based flow control scheme with utility functions for flow groups, achieving near-optimal performance without relying on arrival statistics.

Findings

Distributed threshold-based packet dropping maximizes throughput.

The scheme achieves near-optimal utility in overload conditions.

Performance is validated through simulations.

Abstract

We consider utility maximization in networks where the sources do not employ flow control and may consequently overload the network. In the absence of flow control at the sources, some packets will inevitably have to be dropped when the network is in overload. To that end, we first develop a distributed, threshold-based packet dropping policy that maximizes the weighted sum throughput. Next, we consider utility maximization and develop a receiver-based flow control scheme that, when combined with threshold-based packet dropping, achieves the optimal utility. The flow control scheme creates virtual queues at the receivers as a push-back mechanism to optimize the amount of data delivered to the destinations via back-pressure routing. A novel feature of our scheme is that a utility function can be assigned to a collection of flows, generalizing the traditional approach of optimizing per-flow utilities. Our control policies use finite-buffer queues and are independent of arrival statistics. Their near-optimal performance is proved and further supported by simulation results.