Esteban Carisimo

selected publications

1. Jitterbug: A new framework for jitter-based congestion inference

   Carisimo, Esteban, Mok, Ricky K. P., Clark, David D., and Claffy, Kc

   In Passive and Active Measurement 2022

   Abs PDF Slides GitHub Video

   We investigate a novel approach to the use of jitter to infer network congestion using data collected by probes in access networks. We discovered a set of features in jitter and jitter dispersion —a jitter- derived time series we define in this paper— time series that are char- acteristic of periods of congestion. We leverage these concepts to create a jitter-based congestion inference framework that we call Jitterbug. We apply Jitterbug’s capabilities to a wide range of traffic scenarios and discover that Jitterbug can correctly identify both recurrent and one-off congestion events. We validate Jitterbug inferences against state-of-the- art autocorrelation-based inferences of recurrent congestion. We find that the two approaches have strong congruity in their inferences, but Jitter- bug holds promise for detecting one-off as well as recurrent congestion. We identify several future directions for this research including lever- aging ML/AI techniques to optimize performance and accuracy of this approach in operational settings.

2. Quantifying Nations’ Exposure to Traffic Observation and Selective Tampering

   Gamero-Garrido, Alexander,  Carisimo, Esteban, Hao, Shuai, Huffaker, Bradley, Snoeren, Alex C., and Dainotti, Alberto

   Best dataset award
   

   In Passive and Active Measurement 2022

   Abs PDF GitHub

   Almost all popular Internet services are hosted in a select set of countries, forcing other nations to rely on international connectivity to access them. We identify nations where traffic towards a large portion of the country is serviced by a small number of Autonomous Systems, and, therefore, may be exposed to observation or selective tampering by these ASes. We introduce the Country-level Transit Influence (CTI) metric to quantify the significance of a given AS on the international transit service of a particular country. By studying the CTI values for the top ASes in each country, we find that 34 nations have transit ecosystems that render them particularly exposed, where a single AS is privy to traffic destined to over 40% of their IP addresses. In the nations where we are able to validate our findings with in-country operators, our top- five ASes are 90% accurate on average. In the countries we examine, CTI reveals two classes of networks frequently play a particularly prominent role: submarine cable operators and state-owned ASes.

3. Identifying ASes of State-Owned Internet Operators

   Carisimo, Esteban, Gamero-Garrido, Alexander, Snoeren, Alex C., and Dainotti, Alberto

   In ACM Internet Measurement Conference (IMC) 2021

   Abs HTML PDF Slides GitHub

   In this paper we present and apply a methodology to accurately identify state-owned Internet operators worldwide and their Autonomous System Numbers (ASNs). Obtaining an accurate dataset of ASNs of state-owned Internet operators enables studies where state ownership is an important dimension, including research related to Internet censorship and surveillance, cyber-warfare and international relations, ICT development and digital divide, critical infrastructure protection, and public policy. Our approach is based on a multi-stage, in-depth manual analysis of datasets that are highly diverse in nature. We find that each of these datasets contributes in different ways to the classification process and we identify limitations and shortcomings of these data sources. We obtain the first data set of this type, make it available to the research community together with the several lessons we learned in the process, and perform a preliminary analysis based on our data. We find that 53% (i.e., 123) of the world’s countries are majority owners of Internet operators, highlighting that this is a widespread phenomenon. We also find and document the existence of subsidiaries of state-owned governments operating in foreign countries, an aspect that touches every continent and particularly affects Africa. We hope that this work and the associated data set will inspire and enable a broad set of Internet measurement studies and interdisciplinary research.