Article

Machine learning for measurement-based bandwidth estimation

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Abstract

The dispersion that arises when packets traverse a network carries information that can reveal relevant network characteristics. Using a fluid-flow model of a bottleneck link with first-in first-out multiplexing, accepted probing tools measure the packet dispersion to estimate the available bandwidth, i.e., the residual capacity that is left over by other traffic. Difficulties arise, however, if the dispersion is distorted compared to the model, e.g., by non-fluid traffic, multiple bottlenecks, clustering of packets due to interrupt coalescing, and inaccurate time-stamping in general. It is recognized that modeling these effects is cumbersome if not intractable. This motivates us to explore the use of machine learning in bandwidth estimation. We train a neural network using vectors of the packet dispersion that is characteristic of the available bandwidth. Our testing results reveal that even a shallow neural network identifies the available bandwidth with high precision. We also apply the neural network under a variety of notoriously difficult conditions that have not been included in the training, such as randomly generated networks with the multiple bottleneck links and heavy cross traffic burstiness. Compared to two state-of-the-art model-based techniques as well as a recent machine learning-based technique (Yin et al., 2016), our neural network approach shows improved performance. Further, our neural network can effectively control the estimation procedure in an iterative implementation. We also evaluate our method with other supervised machine learning techniques.

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... It is also important to note that while deploying an admission control scheme, focus should not be directed on only the gateway for QoS to be maintained in MANET. There must be adequate provision for locations that are hotspot centred, especially those locations around the MAC layer [8]. All these requirements were considered during the designing of our proposed admission control algorithm to achieve a good and guaranteed QoS in MANET. ...
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... 3) Multiple Tight Links: We extend our testbed from the single-hop network to the multi-hop network, as shown in Fig. 2 Fig. 9. A two-hop network where the tight link differs from the bottleneck link [30]. ...
... (a) Rate response curves[30]200 400 600 800 1000 Steps 0 20 40 60 80 100 Available Bandwidth Estimates (Mbps) True available bandwidth Direct probing Reinforcement learning Direct probing (SD) Reinforcement learning (SD) (b) Available bandwidth estimates for scenario I 200 400 600 800 1000 Steps 0 20 40 60 80 100 Available Bandwidth Estimates (Mbps) True available bandwidth Direct probing Reinforcement learning Direct probing (SD) Reinforcement learning (SD) (c) Available bandwidth estimates for scenario II ...
Preprint
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Preprint
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Preprint
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... By load-or interchangeably, traffic demands-(S ), we can refer, simply, the bandwidth-usage time series in absolute terms-i.e., Mb/s-or normalized by capacity to make equally relevant each PoP of a path-i.e., in percentage of use. Alternatively, such traffic-demand time series can be the complementary of the available bandwidth per PoP-i.e., the difference between capacity and used bandwidth [40,41]. In such a way, the valley time of two PoPs would be that moment when more aggregate bandwidth is available instead of the moment with less bandwidth in use. ...
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... The network status is measured periodically, including the network bandwidth and transmission latency. The available network bandwidth measurement approaches include variable packet size (VPS), packet pair, probing gap model and probing rate model 4 . ...
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... We provide data sets generated in a controlled network testbed located at Leibniz University Hannover for training and testing of our proposed method. The work in this chapter is based on joint work with Markus Fidler and Bodo Rosenhahn [40,41]. ...
Thesis
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Today’s Internet Protocol (IP), the Internet’s network-layer protocol, provides a best-effort service to all users without any guaranteed bandwidth. However, for certain applications that have stringent network performance requirements in terms of bandwidth, it is significantly important to provide Quality of Service (QoS) guarantees in IP networks. The end-to-end available bandwidth of a network path, i.e., the residual capacity that is left over by other traffic, is determined by its tight link, that is the link that has the minimal available bandwidth. The tight link may differ from the bottleneck link, i.e., the link with the minimal capacity. Passive and active measurements are the two fundamental approaches used to estimate the available bandwidth in IP networks. Unlike passive measurement tools that are based on the non-intrusive monitoring of traffic, active tools are based on the concept of self-induced congestion. The dispersion, which arises when packets traverse a network, carries information that can reveal relevant network characteristics. Using a fluid-flow probe gap model of a tight link with First-in, First-out (FIFO) multiplexing, accepted probing tools measure the packet dispersion to estimate the available bandwidth. Difficulties arise, however, if the dispersion is distorted compared to the model, e.g., by non-fluid traffic, multiple tight links, clustering of packets due to interrupt coalescing and inaccurate time-stamping in general. It is recognized that modeling these effects is cumbersome if not intractable. To alleviate the variability of noise-afflicted packet gaps, the state-of-the-art bandwidth estimation techniques use post-processing of the measurement results, e.g., averaging over several packet pairs or packet trains, linear regression, or a Kalman filter. These techniques, however, do not overcome the basic assumptions of the deterministic fluid model. While packet trains and statistical post-processing help to reduce the variability of available bandwidth estimates, these cannot resolve systematic deviations such as the underestimation bias in case of random cross traffic and multiple tight links. The limitations of the state-of-the-art methods motivate us to explore the use of machine learning in end-to-end active and passive available bandwidth estimation. We investigate how to benefit from machine learning while using standard packet train probes for active available bandwidth estimation. To reduce the amount of required training data, we propose a regression-based scaleinvariant method that is applicable without prior calibration to networks of arbitrary capacity. To reduce the amount of probe traffic further, we implemen a neural network that acts as a recommender and can effectively select the probe rates that reduce the estimation error most quickly. We also evaluate our method with other regression-based supervised machine learning techniques. Furthermore, we propose two different multi-class classification-based methods for available bandwidth estimation. The first method employs reinforcement learning that learns through the network path’s observations withou having a training phase. We formulate the available bandwidth estimation as a single-state Markov Decision Process (MDP) multi-armed bandit problem and implement the "-greedy algorithm to find the available bandwidth, where " is a parameter that controls the exploration vs. exploitation trade-off. We propose another supervised learning-based classification method to obtain reliable available bandwidth estimates with a reduced amount of network overhead in networks, where available bandwidth changes very frequently. In such networks, reinforcement learning-based method may take longer to converge as it has no training phase and learns in an online manner. We also evaluate our method with different classification-based supervised machine learning techniques. Furthermore, considering the correlated changes in a network’s traffic through time, we apply filtering techniques on the estimation results in order to track the available bandwidth changes. Active probing techniques provide flexibility in designing the input structure. In contrast, the vast majority of Internet traffic is Transmission Contro Protocol (TCP) flows that exhibit a rather chaotic traffic pattern. We investigate how the theory of active probing can be used to extract relevant information from passive TCP measurements. We extend our method to perform the estimation using only sender-side measurements of TCP data and acknowledgmen packets. However, non-fluid cross traffic, multiple tight links, and packet loss in the reverse path may alter the spacing of acknowledgments and hence increase the measurement noise. To obtain reliable available bandwidth estimates from noise-afflicted acknowledgment gaps we propose a neural network-based method. We conduct a comprehensive measurement study in a controlled network testbed at Leibniz University Hannover. We evaluate our proposed methods under a variety of notoriously difficult network conditions that have not been included in the training such as randomly generated networks with multiple tight links, heavy cross traffic burstiness, delays, and packet loss. Our testing results reveal that our proposed machine learning-based techniques are able to identify the available bandwidth with high precision from active and passive measurements. Furthermore, our reinforcement learning-based method without any training phase shows accurate and fast convergence to available bandwidth estimates.
... The variability of the available bandwidth estimates of the direct method is comparably large and the average underestimates the true available bandwidth. Though variability of estimates could be due to a number of reasons [30], particularly in this case, the exponential cross traffic deviates from the fluid model and causes random fluctuations of the measurements of g ack . The neural network-based method improves bandwidth estimates significantly. ...
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A measurement study of available bandwidth estimation tools
  • J Strauss
  • D Katabi
  • F Kaashoek