Shortcuts through Colocation Facilities

Network overlays, running on top of the existing Internet substrate, are of perennial value to Internet end-users in the context of, e.g., real-time applications. Such overlays can employ traffic relays to yield path latencies lower than the direct paths, a phenomenon known as Triangle Inequality Violation (TIV). Past studies identify the opportunities of reducing latency using TIVs. However, they do not investigate the gains of strategically selecting relays in Colocation Facilities (Colos). In this work, we answer the following questions: (i) how Colo-hosted relays compare with other relays as well as with the direct Internet, in terms of latency (RTT) reductions; (ii) what are the best locations for placing the relays to yield these reductions. To this end, we conduct a large-scale one-month measurement of inter-domain paths between RIPE Atlas (RA) nodes as endpoints, located at eyeball networks. We employ as relays Planetlab nodes, other RA nodes, and machines in Colos. We examine the RTTs of the overlay paths obtained via the selected relays, as well as the direct paths. We find that Colo-based relays perform the best and can achieve latency reductions against direct paths, ranging from a few to 100s of milliseconds, in 76% of the total cases; 75% (58% of total cases) of these reductions require only 10 relays in 6 large Colos.Comment: In Proceedings of the ACM Internet Measurement Conference (IMC '17), London, GB, 201

Исследование структурных свойств сети Интернет на основе метаграфовых моделей

Studying the Internet its structure is usually divided into levels: Autonomous Systems Level (AS), Point of Presence Level (PoP), Router Level, etc. The global network can be represented on each of them as a graph based on the initial data obtained from open sources. Consideration of a network within the framework of a separate level facilitates analysis, but does not allow to systematically assess its structural properties when providing the connectivity between several segments of the network related, particularly, to the objects of critical information infrastructure. To overcome this contradiction, a mathematical model of the global network in the form of a metagraph was developed at the interface between AS-level and PoP-level that takes into account the characteristics of each level and allows to find bottlenecks both in the interdomain routing system and in the topology of internal networks of Internet providers. Based on the proposed model some structural phenomena of the global network are described: stub, multihomed and transit autonomous systems, content providers. Taking into account available data from open sources about Internet structure, a method for constructing a metagraph is proposed. A comparative analysis of tools that automate the process of analyzing a network model is carried out. The practice-oriented problems of finding a cutting subset in a metagraph were set. Certain areas of further research are software implementation of the models using module MGtoolkit in Python and the assessment of structural phenomena of Russian segments of the Internet.При исследовании сети Интернет ее структуру разделяют на уровни: уровень автономных систем, уровень точек присутствия операторов связи, уровень оборудования и так далее. На каждом из них глобальная сеть может быть описана в виде графа на основании исходных данных, получаемых из открытых источников. Рассмотрение сети в рамках отдельного уровня упрощает анализ, однако не позволяет системно оценить ее структурные свойства при решении задач обеспечения связности нескольких сегментов сети, относящихся, в частности, к объектам критической информационной инфраструктуры. Для преодоления этого противоречия разработана математическая модель глобальной сети на стыке уровня автономных систем и уровня точек присутствия операторов связи в виде метаграфа, которая учитывает особенности каждого из уровней и позволяет находить «узкие» места как в системе междоменной маршрутизации, так и в топологии внутренних сетей интернет-провайдеров. На основе предложенной модели описаны некоторые структурные феномены глобальной сети: тупиковые, многоинтерфейсные и транзитные автономные системы, контент-провайдеры. С учетом доступных в открытых источниках данных о структуре сети Интернет предложен способ построения метаграфа. Проведен сравнительный анализ инструментов, автоматизирующих процесс анализа модели сети. Сформулированы ориентированные на практику задачи поиска разрезающего подмножества в метаграфе. Определены направления дальнейших исследований – программная реализация инструментов анализа структуры глобальной сети с использованием общедоступного модуля MGtoolkit на языке Python и оценивание структурных феноменов российского сегмента сети Интернет

Исследование структурных свойств сети Интернет на основе метаграфовых моделей

При исследовании сети Интернет ее структуру разделяют на уровни: уровень автономных систем, уровень точек присутствия операторов связи, уровень оборудования и так далее. На каждом из них глобальная сеть может быть описана в виде графа на основании исходных данных, получаемых из открытых источников. Рассмотрение сети в рамках отдельного уровня упрощает анализ, однако не позволяет системно оценить ее структурные свойства при решении задач обеспечения связности нескольких сегментов сети, относящихся, в частности, к объектам критической информационной инфраструктуры. Для преодоления этого противоречия разработана математическая модель глобальной сети на стыке уровня автономных систем и уровня точек присутствия операторов связи в виде метаграфа, которая учитывает особенности каждого из уровней и позволяет находить «узкие» места как в системе междоменной маршрутизации, так и в топологии внутренних сетей интернет-провайдеров. На основе предложенной модели описаны некоторые структурные феномены глобальной сети: тупиковые, многоинтерфейсные и транзитные автономные системы, контент-провайдеры. С учетом доступных в открытых источниках данных о структуре сети Интернет предложен способ построения метаграфа. Проведен сравнительный анализ инструментов, автоматизирующих процесс анализа модели сети. Сформулированы ориентированные на практику задачи поиска разрезающего подмножества в метаграфе. Определены направления дальнейших исследований – программная реализация инструментов анализа структуры глобальной сети с использованием общедоступного модуля MGtoolkit на языке Python и оценивание структурных феноменов российского сегмента сети Интернет

ENDEAVOUR: A Scalable SDN Architecture For Real-World IXPs.

Innovation in interdomain routing has remained stagnant for over a decade. Recently, IXPs have emerged as economically-advantageous interconnection points for reducing path latencies and exchanging ever increasing traffic volumes among, possibly, hundreds of networks. Given their far-reaching implications on interdomain routing, IXPs are the ideal place to foster network innovation and extend the benefits of SDN to the interdomain level. In this paper, we present, evaluate, and demonstrate EN- DEAVOUR, an SDN platform for IXPs. ENDEAVOUR can be deployed on a multi-hop IXP fabric, supports a large number of use cases, and is highly-scalable while avoiding broadcast storms. Our evaluation with real data from one of the largest IXPs, demonstrates the benefits and scalability of our solution: ENDEAVOUR requires around 70% fewer rules than alternative SDN solutions thanks to our rule partitioning mechanism. In addition, by providing an open source solution, we invite ev- eryone from the community to experiment (and improve) our implementation as well as adapt it to new use cases.European Union’s Horizon 2020 research and innovation programme under the ENDEAVOUR project (grant agreement 644960)

Bias in Internet Measurement Platforms

Network operators and researchers frequently use Internet measurement platforms (IMPs), such as RIPE Atlas, RIPE RIS, or RouteViews for, e.g., monitoring network performance, detecting routing events, topology discovery, or route optimization. To interpret the results of their measurements and avoid pitfalls or wrong generalizations, users must understand a platform's limitations. To this end, this paper studies an important limitation of IMPs, the \textit{bias}, which exists due to the non-uniform deployment of the vantage points. Specifically, we introduce a generic framework to systematically and comprehensively quantify the multi-dimensional (e.g., across location, topology, network types, etc.) biases of IMPs. Using the framework and open datasets, we perform a detailed analysis of biases in IMPs that confirms well-known (to the domain experts) biases and sheds light on less-known or unexplored biases. To facilitate IMP users to obtain awareness of and explore bias in their measurements, as well as further research and analyses (e.g., methods for mitigating bias), we publicly share our code and data, and provide online tools (API, Web app, etc.) that calculate and visualize the bias in measurement setups

Rethinking IXPs' architecture in the age of SDN

© 2018 IEEE. Software-defined Internet eXchange points (SDXs) are a promising solution to the long-standing limitations and problems of interdomain routing. While the proposed SDX architectures have improved the scalability of the control plane, these solutions have ignored the underlying fabric upon which they should be deployed. In this paper, we present Umbrella, a software-defined interconnection fabric that complements and enhances those architectures. Umbrella is a switching fabric architecture and management approach that improves the overall robustness, limiting control plane dependence, and suitable for the topology of any existing Internet eXchange Point (IXP). We validate Umbrella through a real-world deployment on two production IXPs, TouSIX and NSPIXP-3, and demonstrate its use in practice, sharing our experience of the challenges faced

From the edge to the core : towards informed vantage point selection for internet measurement studies

Since the early days of the Internet, measurement scientists are trying to keep up with the fast-paced development of the Internet. As the Internet grew organically over time and without build-in measurability, this process requires many workarounds and due diligence. As a result, every measurement study is only as good as the data it relies on. Moreover, data quality is relative to the research question—a data set suitable to analyze one problem may be insufficient for another. This is entirely expected as the Internet is decentralized, i.e., there is no single observation point from which we can assess the complete state of the Internet. Because of that, every measurement study needs specifically selected vantage points, which fit the research question. In this thesis, we present three different vantage points across the Internet topology— from the edge to the Internet core. We discuss their specific features, suitability for different kinds of research questions, and how to work with the corresponding data. The data sets obtained at the presented vantage points allow us to conduct three different measurement studies and shed light on the following aspects: (a) The prevalence of IP source address spoofing at a large European Internet Exchange Point (IXP), (b) the propagation distance of BGP communities, an optional transitive BGP attribute used for traffic engineering, and (c) the impact of the global COVID-19 pandemic on Internet usage behavior at a large Internet Service Provider (ISP) and three IXPs.Seit den frühen Tagen des Internets versuchen Forscher im Bereich Internet Measu- rement, mit der rasanten Entwicklung des des Internets Schritt zu halten. Da das Internet im Laufe der Zeit organisch gewachsen ist und nicht mit Blick auf Messbar- keit entwickelt wurde, erfordert dieser Prozess eine Meg Workarounds und Sorgfalt. Jede Measurement Studie ist nur so gut wie die Daten, auf die sie sich stützt. Und Datenqualität ist relativ zur Forschungsfrage - ein Datensatz, der für die Analyse eines Problems geeiget ist, kann für ein anderes unzureichend sein. Dies ist durchaus zu erwarten, da das Internet dezentralisiert ist, d. h. es gibt keinen einzigen Be- obachtungspunkt, von dem aus wir den gesamten Zustand des Internets beurteilen können. Aus diesem Grund benötigt jede Measurement Studie gezielt ausgewählte Beobachtungspunkte, die zur Forschungsfrage passen. In dieser Arbeit stellen wir drei verschiedene Beobachtungspunkte vor, die sich über die gsamte Internet-Topologie erstrecken— vom Rand bis zum Kern des Internets. Wir diskutieren ihre spezifischen Eigenschaften, ihre Eignung für verschiedene Klas- sen von Forschungsfragen und den Umgang mit den entsprechenden Daten. Die an den vorgestellten Beobachtungspunkten gewonnenen Datensätze ermöglichen uns die Durchführung von drei verschiedenen Measurement Studien und damit die folgenden Aspekte zu beleuchten: (a) Die Prävalenz von IP Source Address Spoofing bei einem großen europäischen Internet Exchange Point (IXP), (b) die Ausbreitungsdistanz von BGP-Communities, ein optionales transitives BGP-Attribut, das Anwendung im Bereich Traffic-Enigneering findet sowie (c) die Auswirkungen der globalen COVID- 19-Pandemie auf das Internet-Nutzungsverhalten an einem großen Internet Service Provider (ISP) und drei IXPs

On the latency impact of remote peering

Internet Exchange Points (IXPs) play an essential role in the Internet, providing a fabric for thousands of Autonomous Systems (ASes) to interconnect. Initially designed to keep local traffic local, IXPs now interconnect ASes all over the world, and the premise that IXP routes should be shorter and faster than routes through a transit provider may not be valid anymore. Using BGP views from eight IXPs (three in Brazil, two in the U.S., and one each in London, Amsterdam, and Johannesburg), a transit connection at each of these locations, and latency measurements we collected in May 2021, we compare the latency to reach the same addresses using routes from remote peers, local peers, and transit providers. For four of these IXPs, at least 71.4% of prefixes advertised by remote peers also had a local peering route, BGP generally preferred the remote route due to its shorter AS path, but the local route had lower latency than the remote route in the majority of cases. When a remote route was the only peering route available at an IXP, it had slightly lower latency than a corresponding transit route available outside the IXP for >57.6% of the prefixes for seven of the eight IXPs