Virtual Insanity: Linear Subnet Discovery

Abstract

Over the past two decades, the research community has developed many approaches to study the Internet topology. In particular, starting from 2007, various tools explored the inference of subnets, i.e., sets of devices located on the same connection medium which can communicate directly with each other at the link layer.In this paper, we first discuss how today's traffic engineering policies increase the difficulty of subnet inference. We carefully characterize typical difficulties and quantify them in the wild. Next, we introduce WISE (Wide and lInear Subnet inferencE), a new tool which tackles those difficulties and discovers, in a linear time, large networks subnets. Based on two ground truth networks, we demonstrate that WISE outperforms state-of-theart tools. Then, through large-scale measurements, we show that the selection of a vantage point with WISE has a marginal effect regarding accuracy. Finally, we discuss how subnets can be used to infer neighborhoods (i.e., aggregates of subnets located at most one hop from each other). We discuss how these neighborhoods can lead to bipartite models of the Internet and present validation results and an evaluation of neighborhoods in the wild, using WISE. Both our code and data are freely available.

An efficient post-processing adaptive filtering technique to rectifying the flickering effects

“…Due to a one-dimensional filtering approach, the in-loop processing method enhances the coding efficiency by reducing blocking artifacts amongst adjoining pixels or frames but is unable to process corner outliers. To alleviate blocking artifacts different post-processing approaches such as frequency domain analysis , Projection Onto Convex Sets (POCS) [9][10][11][12][13], waveletbased techniques [8,[20][21][22][23][24][25][26][27][28][29][30], estimation theory [5,[9][10][11][12][13], and filtering approach [11][12][13][14][15] has been proposed in last few decades. The most common method is to apply a low-pass filter across block boundaries to remove artifacts.…”

“…Henceforth smoothing channel planned in ( 10) and ( 11) is executed to finish a bunch of PVs (evenly just as vertically). On the off chance that (9) isn't fulfilled, to save picture subtleties across the edges, another level edge channel has been created and is given by (12).…”

ISP Probing Reduction with Anaximander

“…Secondly, Ingress Reduction was applicable for Rocketfuel because of its probing design, that initially assigns the complete target list to each VP (meaning that all targets are probed from each VP if no reduction applies). In our case however, our reference dataset subdivides the target list among VPs in order to speed up the probing process (by design, the same destination is not probed from two VPs or more), as it has little impact on the overall quality of discovered data [15]. For those two reasons, we will not consider Ingress Reduction for our study, or any other optimization that could be done on VP placement or targets specific balancing among VPs.…”