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TUB internet network research papers accepted at CoNEXT 2020 and COVID-19 network impacts workshop 2020

Multiple papers by researchers in the Internet Network Architectures (INET) group at TU Berlin, headed by Prof. Dr. Georgios Smaragdakis, were accepted or presentation or publication this fall.

The paper “Keep your Communities Clean: Exploring the Routing Message Impact of BGP Communities” by Thomas Krenc, Robert Beverly, and Georgios Smaragdakis was accepted at the 16th International Conference on emerging Networking EXperiments and Technologies (ACM CoNEXT 2020), a major forum for presentations and discussions of novel networking technologies, which will take place from December 1 -4, 2020.

Additionally, the paper “A view of Internet Traffic Shifts at ISP and IXPs during the COVID-19 Pandemic” by Anja Feldmann, Oliver Gasser, Georgios Smaragdakis et al. was presented at the Internet Architecture Board COVID-19 Network Impacts Workshop, 2020. This workshop is held to convene interested researchers, network operators, and network management experts, and Internet technologists to share their experiences.

A third publication of the INET group was accepted for publication in IEEE Transactions on Network and Service Management, 2020 (TNSM 2020) in a special issue on Data Analytics and Machine Learning for Network and Service Management. “Exploring Network-Wide Flow Data with Flowyager” by Said Jawad Saidi, Aniss Maghsoudlou, Damien Foucard, Georgios Smaragdakis, Ingmar Poese, and Anja Feldmann investigates how to improve the response time for a priori unknown network-wide queries.

THE PAPERS IN DETAIL:

Authors:
Thomas Krenc, Robert Beverly, and Georgios Smaragdakis

Abstract:
BGP communities are widely used to tag prefix aggregates for policy, traffic engineering, and inter-AS signaling. Because individual ASes define their own community semantics, many ASes blindly propagate communities they do not recognize. Prior research has shown the potential security vulnerabilities when communities are not filtered. This work sheds light on a second unintended side-effect of communities and permissive propagation: an increase in unnecessary BGP routing messages. Due to its transitive property, a change in the community attribute induces update messages throughout established routes, just updating communities. We ground our work by characterizing the handling of updates with communities, including when filtered, on multiple real-world BGP implementations in controlled laboratory experiments. We then examine 10 years of BGP messages observed in the wild at two route collector systems. In 2020, approximately 25% of all announcements modify the community attribute, but retain the AS path of the most recent announcement; an additional 25% update neither community nor AS path. Using predictable beacon prefixes, we demonstrate that communities lead to an increase in update messages both at the tagging AS and at neighboring ASes that neither add nor filter communities. This effect is prominent for geolocation communities during path exploration: on a single day, 63% of all unique community attributes are revealed exclusively due to global withdrawals.

Preprint

Data:
https://www.cmand.org/communityexploration/ (Supported by European Research Council (ERC) Starting Grant ResolutioNet (ERCStG-679158))

Authors:
Anja Feldmann, Oliver Gasser, Franziska Lichtblau, Enric Pujol, Ingmar Poese, Christoph Dietzel, Daniel Wagner, Matthias Wichtlhuber, Juan Tapiador, Narseo Vallina-Rodriguez, Oliver Hohlfeld, and Georgios Smaragdakis

Abstract:
In this position paper, we report on a measurement study on Internet traffic shifts due to the COVID-19 pandemic using data from a diverse set of vantage points (one ISP, three IXPs, a metropolitan educational network, and a mobile operator). We observe that the traffic volume increased by 15-20%almost within a week—while overall still modest, this constitutes a large increase within this short time period. However, despite this surge, we observe that the Internet infrastructure is able to handle the new volume, as most traffic shifts occur outside of traditional peak hours. When looking directly at the traffic sources, it turns out that, while hypergiants still contribute a significant fraction of traffic we see (1)a higher percentage increase in traffic of non-hypergiants, and (2) traffic increases in applications that people use when at home, such as Web conferencing, VPN, and gaming. While many networks see increased traffic demands, in particular, those providing services to residential users, academic networks experience major overall decreases. Yet, in these networks, we can observe substantial increases when considering applications associated to remote working and lecturing.

Full Paper

Authors:
Said Jawad Saidi, Aniss Maghsoudlou, Damien Foucard, Georgios Smaragdakis, Ingmar Poese, and Anja Feldmann

Abstract:
Many network operations, ranging from attack investigation and mitigation to traffic management, require answering network-wide flow queries in seconds. Although flow records are collected at each router, using available traffic capture utilities, querying the resulting datasets from hundreds of routers across sites and over time, remains a significant challenge due to the sheer traffic volume and distributed nature of flow records.
In this paper, we investigate how to improve the response time for a priori unknown network-wide queries. We present Flowyager, a system that is built on top of existing traffic capture utilities. Flowyager generates and analyzes tree data structures, that we call Flowtrees, which are succinct summaries of the raw flow data available by capture utilities. Flowtrees are self-adjusted data structures that drastically reduce space and transfer requirements, by 75% to 95%, compared to raw flow records. Flowyager manages the storage and transfers of Flowtrees, supports Flowtree operators, and provides a structured query language for answering flow queries across sites and time periods. By deploying a Flowyager prototype at both a large Internet Exchange Point and a Tier-1 Internet Service Provider, we showcase its capabilities for networks with hundreds of router interfaces. Our results show that the query response time can be reduced by an order of magnitude when compared with alternative data analytics platforms. Thus, Flowyager enables interactive network-wide queries and offers unprecedented drill-down capabilities to, e.g., identify DDoS culprits, pinpoint the involved sites, and determine the length of the attack.

Preprint

Data:
https://github.com/saidjawad/Flowyager (supported by European Research Council (ERC) Starting Grant ResolutioNet (ERCStG-679158))