Optimizing Packet Dropping by Efficient Congesting-Flow Isolation in Lossy Data-Center Networks

One of the most serious threats to the performance of data-center systems (DCs) is network congestion, that increases latency and reduces throughput dramatically. The Dynamic Virtual Lanes (DVL) technique has been proposed to deal with congestion in Ethernet-based lossless data-center networks (DCNs). DVL is based on isolating congesting flows in special queues, so that they do not share queues with non-congesting ones. In this way, Head-of-Line blocking is prevented and the probability of standard queues becoming congested is drastically reduced. This paper explains how a DVL-like approach can be used also in lossy DCNs, with several benefits. Specifically and mainly, packet dropping is reduced for non-congesting flows. In addition, latency and throughput degradations are smaller. The results shown in the paper confirm that these benefits are achieved just by adding a single additional, special queue per switch port.