Evaluation of the impact of packet drops due to AQM over capacity limited paths

For many years Internet routers have been designed and benchmarked in ways that encourage the use of large buffers. When these buffers accumulate a large standing queue, this can lead to high network path latency. Two AQM algorithms: PIE and CoDel, have been recently proposed to reduce buffer latency by avoiding the drawbacks of previous AQM algorithms like RED. This paper explores the performance of these new algorithms in simulated rural broadband networks where capacity is limited. We compared the new algorithms using Adaptive RED as a reference. We observe that to achieve a small queuing delay PIE and CoDel both increase packet loss. We therefore explored this impact on the quality of experience for loss-sensitive unreliable multimedia applications, such as real-time and near-real-time video. The results from simulations show that PIE performs better than CoDel in terms of packet loss rates affecting video quality. We also noted that the performance of ARED is comparable to that of PIE and CoDel in constant capacity links. This suggests that AQM in general is useful for limited capacity network paths.