1,720,962 research outputs found
Tomografía de la red en un IXP: Primer análisis del PIT Bolivia
Get PDFInternet Exchange Points (IXPs) have been responsible for leading the most significant change on Internet ecosystem in the last 15 years. Despite the popularity of IXPs, a large number of countries delayed to introduce this infrastructure in their national networks. In 2013, Bolivia encouraged the creating of a national IXP, which motivated us to make the first study about an IXP in Latin America, in a country which had not deployed this infrastructure yet. However, due to the lack of vantage points of measurement projects in Bolivia, it was necessary to develop and deploy a measurement platform, which was called PladMeD, to be able to analyze the influence of the IXP. This works presents a six-month analysis about the influence of the IXP on the national network and it mainly focuses on the modifications in the interconnection as well as the quality of service.Fil: Carisimo, Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long". Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long"; Argentin
Studying the evolution of content providers in IPv4 and IPv6 internet cores
No full textThere is recent evidence that the core of the Internet, which was formerly dominated by large transit providers, has been reshaped after the transition to a multimedia-oriented network, first by general-purpose CDNs and now by private CDNs. In this work we use k-cores, an element of graph theory, to define which ASes compose the core of the Internet and to track the evolution of the core since 1999. Specifically, we investigate whether large players in the Internet content and CDN ecosystem belong to the core and, if so, since when. In addition, we examine differences between the IPv4 and IPv6 cores. We further investigate regional differences in the evolution of large content providers. Finally, we show that the core of the Internet has incorporated an increasing number of content ASes in recent years. To enable reproducibility of this work, we provide a website to allow interactive analysis of our datasets to detect, for example, “up and coming” ASes using customized queries.Fil: Carisimo, Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long". Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long"; ArgentinaFil: Selmo, Carlos. Instituto Tecnológico de Buenos Aires; ArgentinaFil: Alvarez Hamelin, José Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long". Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long"; ArgentinaFil: Dhamdhere, Amogh. No especifíca
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
A first look at the Latin American IXPs
No full textWe investigated Internet eXchange Points (IXPs) deployed across Latin America. We discovered that many Latin American states have been actively involved in the development of their IXPs. We further found a correlation between the success of a national IXP and the absence of local monopolistic ASes that concentrate the country's IPv4 address space. In particular, three IXPs have been able to gain local traction: IX.br-SP, CABASE-BUE and PIT Chile- SCL. We further compared these larger IXPs with others outside Latin America. We found that, in developing regions, IXPs have had a similar growth in the last years and are mainly populated by regional ASes. The latter point clearly contrasts with more internationally re-known European IXPs whose members span multiple regions.Fil: Carisimo, Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long". Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long"; ArgentinaFil: Del Fiore, Julian M.. Université de Strasbourg; FranciaFil: Dujovne, Diego. Universidad Diego Portales; ChileFil: Pelsser, Cristel. Université de Strasbourg; FranciaFil: Alvarez Hamelin, José Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long". Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long"; Argentin
Promises and Potential of BBRv3
Get PDFThe Bottleneck-Bandwidth and Round-trip (BBR) congestion control algorithm was introduced by Google in 2016. Unlike prior congestion-control algorithms (CCAs), BBR does not rely on signals that are weakly correlated with congestion (e.g., packet loss and transient queue delay). Instead, it characterizes a path using two parameters, bottleneck bandwidth and round-trip propagation time, and is designed to converge with a high probability to Kleinrock’s optimal operating point [34]. Essentially, in stable state, BBR maximizes throughput while minimizing delay and loss. Google has used BBR for a significant fraction of its network traffic both within its datacenters and on its WAN since 2017 [15]. BBR’s interaction dynamics with Cubic, the widely used CCA in the Internet, has received intense scrutiny: Some studies observed BBR to be unfair to Cubic, or generally loss-based CCAs. Google, to its credit, has diligently revised BBR’s design to address the criticisms. This paper focuses on characterizing the promises and potential of the third, and most recent, revision of BBR—introduced to the public in July 2023. We empirically evaluate BBRv3’s performance across a range of network scenarios, e.g., considering different buffer sizes, round-trip times, packet losses, and flow-size distributions. We show that despite the improvements and optimizations introduced in BBRv3, it struggles to achieve an equitable sharing of bandwidth when competing with Cubic, the widely used CCA in the Internet, in a wide range of network conditions.</p
Swamp of Reflectors:Investigating the Ecosystem of Open DNS Resolvers
Get PDFDNS reflection-based DDoS attacks rely on open DNS resolvers to reflect and amplify attack traffic towards victims. While the majority of these resolvers are considered to be open because of misconfiguration, there remains a lot to be learned about the open resolver ecosystem. In this paper, we investigate and characterize open DNS resolvers from multiple angles. First, we look at indicators that likely suggest an intention behind the existence of open resolvers. To this end, we cross open resolver IP addresses with reverse DNS measurement data and show that a relatively small group of open resolvers unmistakably indicate their service in hostnames (i.e., PTR records). Second, we investigate the extent to which anycast technique is used among open resolvers and show that this is mainly driven by hypergiants. Additionally, we take a look at the exposure of the authoritative nameservers as open recursive resolvers and show that a non-negligible number of authoritative nameservers also serve as open recursors. Finally, we look at the persistency of open resolvers over time. We study open resolvers longitudinally over a three-year period and show that 1% of open resolvers persistently appear in more than 95% of the measurement snapshots.</p
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
From Power to Water:Dissecting SCADA Networks Across Different Critical Infrastructures
Get PDFIn recent years, there has been an increasing need to understand the SCADA networks that oversee our essential infrastructures. While previous studies have focused on networks in a single sector, few have taken a comparative approach across multiple critical infrastructures. This paper dissects operational SCADA networks of three essential services: power grids, gas distribution, and water treatment systems. Our analysis reveals some distinct and shared behaviors of these networks, shedding light on their operation and network configuration. Our findings challenge some of the previous perceptions about the uniformity of SCADA networks and emphasize the need for specialized approaches tailored to each critical infrastructure. With this research, we pave the way for better network characterization for cybersecurity measures and more robust designs in intrusion detection systems.</p
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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