1,721,025 research outputs found
Untangling IoT Global Connectivity: The Importance of Mobile Signaling Traffic
Full text linkIoT plays an important role in cellular networks, and its need for global connectivity is driving the rise of Global IoT Providers. These provide service by aggregating multiple mobile providers through roaming, complicating the understanding of the overall mobile ecosystem. This calls for lightweight monitoring solutions, which are crucial to meet the quality demanded by IoT services, and of automatic means to analyze the data, with the final goal to carry out economic and management activities. This paper provides insights from the study of two commercial, widespread IoT providers. We show how monitoring signaling traffic between mobile networks offers a unique opportunity to understand both the IoT customers’ characteristics and the network functioning. Leveraging clustering, we offer the first data-driven methodology to examine large IoT signaling datasets. By analyzing over 1.3 billion signaling dialogues across two providers, we identify common signaling profiles that depend on the specific IoT vertical, likely misconfigured devices, and sudden changes that indicate potential problems. This provides actionable insights for network management decisions and service improvements, and lays the groundwork for future research on IoT traffic modeling
Measuring Roaming in Europe: Infrastructure and Implications on Users QoE
Full text link"Roam like Home" is the initiative of the European Commission to end the levy of extra charges when roaming within the European region. As a result, people can use data services more freely across Europe. However, the implications of roaming solutions on network performance have not been carefully examined yet. This paper provides an in-depth characterization of the implications of international data roaming within Europe. We build a unique roaming measurement platform using 16 different mobile networks deployed in 6 countries across Europe. Using this platform, we measure different aspects of international roaming in 4G networks in Europe, including mobile network configuration, performance characteristics, and quality of experience. We find that operators adopt a common approach to implement roaming called Home-routed roaming. This results in additional latency penalties of 60 ms or more, depending on geographical distance. This leads to worse browsing performance, with an increase in the metrics related to Quality of Experience (QoE) of users (Page Load time and Speed Index) in the order of 15-20%. We further analyze the impact of latency on QoE metrics in isolation and find that the penalty imposed by Home Routing leads to degradation on QoE metrics up to 150% in case of intercontinental roaming. We make our dataset public to allow reproducing the results
Game Theory Application to Interdomain Routing
Full text linkThis thesis proposes a game theoretic analysis of interdomain routing. In the two following chapters we try to capture some of the intricacies of the current Internet routing protocol, the Border Gateway Protocol (BGP).
The first chapter of the thesis paper presents a survey of recent adv ances in the application of game theory to model the behaviour of interdomain routing. In these models, the
participants of the interdomain routing game are represented as strategic agents seeking to improve their benefits through the manipulation of the interdomain routing protoco l BGP.
The main results achieved over the last few years in this field include models to an alyze the stability of the interdomain routing and the design of mechanisms that guarantee BGP to be incentive-compatible with or without monetary transfers. However, over the last years, the research community has been deeply concerned about
the scalability issues that the Internet routing is facing. As the Internet popularity grows, so do the network resources needed in order to sustain its worldwide availability. In the second chapter of this thesis we consider a commons model in which the Global Routing
Table (GRT) is a public resource. We use this model to study the economic incentives the ASes have for deaggregating their assigned address blocks. We evaluate the efficiency of the global routing system, the properties of the game equilibria and we examine its relation
to the social welfare point of the considered game setup. We find that the str ategy adopted by the ASes in the interdomain is not an overall optimum strategy and it leads to an inefficient exploitation of the common resource. Therefore, we prove that the GRT, just like any common natural resource, “remorselessly generates tragedy”, following Hardin’s game theoretic analysis on the tragedy of the commons. Finally, we introduce in the model a pricing
mechanism that aims to avoid the tragedy of the Internet routing commons.Telematics EngineeringUniversidad Carlos III de Madrid, Spainpu
Understanding the Reachability of IPv6 Limited Visibility Prefixes
No full textThe main functionality of the Internet is to provide global connectivity for every node attached to it. In light of the IPv4 address space depletion, large networks are in the process of deploying IPv6. In this paper we perform an extensive analysis of how BGP route propagation affects global reachability of the active IPv6 address space in the context of this unique transition of the Internet infrastructure. We propose and validate a methodology for testing the reachability of an IPv6 address block active in the routing system. Leveraging the global visibility status of the IPv6 prefixes evaluated with the BGP Visibility Scanner, we then use this methodology to verify if the visibility status of the prefix impacts its reachability at the interdomain level. We perform active measurements using the RIPE Atlas platform. We test destinations with different BGP visibility degrees (i.e., limited visibility - LV, high visibility - HV and dark prefixes). We show that the IPv6 LV prefixes (v6LVPs) are generally reachable, mostly due to a less-specific HV covering prefix (v6HVP). However, this is not the case of the dark address space, which, by not having a covering v6HVP is largely unreachable. When talking about the results we present in this paper a better explanation of trace route and some basic concepts of BGP will be provided.FALSEpu
A System for the Detection of Limited Visibility in BGP
Full text linkThe performance of the global routing system is vital to thousands of entities operating the Autonomous Systems (ASes) which make up the Internet. The Border Gateway
Protocol (BGP) is currently responsible for the exchange of reachability information and the selection of paths according to their specified routing policies. BGP thus enables traffic to flow from any point to another connected to the Internet. The manner traffic flows is often influenced by entities in the Internet according to their preferences. The latter are implemented in the form of routing policies by tweaking BGP configurations. Routing policies are usually complex and aim to achieve a myriad goals, including technical, economic and political purposes. Additionally, individual network managers need to
permanently adapt to the interdomain routing changes and, by engineering the Internet traffic, optimize the use of their network.
Despite the flexibility offered, the implementation of routing policies is a complicated process in itself, involving fine-tuning operations. Thus, it is an error-prone task and operators might end up with faulty configurations that impact the efficacy of their strate-
gies or, more importantly, their revenues. Withal, even when correctly defining legitimate routing policies, unforeseen interactions between ASes have been observed to cause important disruptions that affect the global routing system. The main reason behind this resides in the fact that the actual inter-domain routing is the result of the interplay of many routing policies from ASes across the Internet, possibly bringing about a different
outcome than the one expected.
In this thesis, we perform an extensive analysis of the intricacies emerging from the complex netting of routing policies at the interdomain level, in the context of the current operational status of the Internet. Abundant implications on the way traffic flows in the Internet arise from the convolution of routing policies at a global scale, at times resulting in ASes using suboptimal ill-favored paths or in the undetected propagation of configuration errors in the routing system. We argue here that monitoring prefix visibility at the interdomain level can be used to detect cases of faulty configurations or backfired routing policies, which disrupt the functionality of the routing system. We show that the lack of global prefix visibility can offer early warning signs for anomalous events which,
despite their impact, often remain hidden from state of the art tools. Additionally, we show that such unintended Internet behavior not only degrades the efficacy of the routing policies implemented by operators, causing their traffic to follow ill-favored paths, but can also point out problems in the global connectivity of prefixes.
We further observe that majority of prefixes suffering from limited visibility at the interdomain level is a set of more-specific prefixes, often used by network operators to
fulfill binding traffic engineering needs. One important task achieved through the use of routing policies for traffic engineering is the control and optimization of the routing function in order to allow the ASes to engineer the incoming traffic. The advertisement of more-specific prefixes, also known as prefix deaggregation, provides network operators with a fine-grained method to control the interdomain ingress traffic, given that the longest-prefix match rule over-rides any other routing policy applied to the covering less specific prefixes.
Nevertheless, however efficient, this traffic engineering tool comes with a cost, which is usually externalized to the entire Internet community. Prefix deaggregation is a known reason for the artificial inflation of the BGP routing table, which can further affect the
scalability of the global routing system. Looking past the main motivation for deploying deaggregation in the first place, we identify and analyze here the economic impact of
this type of strategy. We propose a general Internet model to analyze the effect that advertising more-specific prefixes has on the incoming transit traffic burstiness. We show that deaggregation combined with selective advertisements (further defined as strategic deaggregation) has a traffic stabilization side-effect, which translates into a decrease of the transit traffic bill. Next, we develop a methodology for Internet Service Providers (ISPs)
to monitor general occurrences of deaggregation within their customer base. Furthermore, the ISPs can detect selective advertisements of deaggregated prefixes, and thus identify customers which may impact the business of their providers. We apply the proposed methodology on a complete set of data including routing, traffic, topological and billing information provided by an operational ISP and we discuss the obtained results.Telematics EngineeringUniversidad Carlos III de Madrid, Spainpu
Tangled: Analysis of AS-level Interconnection in LAC region
No full textDue to its importance, the Internet topology at the Autonomous System(AS) level has been attracting much attention from the research community for over a decade. Internet connectivity is increasingly recognized as a fundamental lever for development, triggering socio-economic progress in the society as a whole. Rich local interconnections between the ASes within a region make up a reliable Internet environment, which further helps to foster the Internet business in the region by promoting innovation and empowering local Internet entities to grow.
We propose an empirical study of the topological organization of the Internet ecosystem in Latin America and the Caribbean (LAC).
While basic connectivity to the global Internet exists throughout the region, the availability and quality of the infrastructure varies widely between different countries or even between different geographical areas within the same country. Using BGP routing data and information about the business relationship between ASes active in the region, we build the graph of Internet connectivity at the country level. We identify how many international ASes operate locally, connecting the local network to other countries within the region and to the global Internet. Based on this information, we analyze how prone a country is to disconnection, both as a consequence of government censorship or external attacks on the local Internet ecosystem. Next, we characterize Internet performance in LAC and observe very high latency between different countries and, sometimes, even within the same country. We observe that a large fraction of paths interconnecting different destinations circuit through the US, and quantify the fraction of destinations in the LAC region that are possibly affected by this phenomenon.FALSEpu
Understanding the Reachability of IPv6 Limited Visibility Prefixes
Full text linkRIPE Academic Cooperation Initiative (RACI) Scholarship – Travel GrantFALSEpu
Speedtest-Like Measurements in 3G/4G Networks: The MONROE Experience
Full text linkMobile Broadband (MBB) Networks are evolving at a fast pace, with technology enhancements that promise drastic improvements in capacity, connectivity, coverage, i.e., better performance in general. But how to measure the actual performance of a MBB solution? In this paper, we present our experience in running the simplest of the performance test: "speedtest-like" measurements to estimate the download speed offered by actual 3G/4G networks. Despite their simplicity, download speed measurements in MBB networks are much more complex than in wired networks, because of additional factors (e.g., mobility of users, physical impairments, diversity in technology, operator settings, mobile terminals diversity, etc.).,, We exploit the MONROE open platform, with hundreds of multihomed nodes scattered in 4 different countries, and explicitly designed with the goal of providing hardware and software solutions to run large scale experiments in MBB networks. We analyze datasets collected in 4 countries, over 11 operators, from about 50 nodes, for more than 2 months. After designing the experiment and instrumenting both the clients and the servers with active and passive monitoring tools, we dig into collected data, and provide insight to highlight the complexity of running even a simple speedtest. Results show interesting facts, like the occasional presence of NAT, and of Performance Enhancing Proxies (PEP), and pinpoint the impact of different network configurations that further complicate the picture. Our results will hopefully contribute to the debate about performance assessment in MBB networks, and to the definition of much needed benchmarks for performance comparisons of 3G, 4G and soon of 5G networks"
Fragmentation, Truncation, and Timeouts: Are Large DNS Messages Falling to Bits?
No full textThe DNS provides one of the core services of the Internet, mapping applications and services to hosts. DNS employs both UDP and TCP as a transport protocol, and currently most DNS queries are sent over UDP. The problem with UDP is that large responses run the risk of not arriving at their destinations – which can ultimately lead to unreachability. However, it remains unclear how much of a problem these large DNS responses over UDP are in the wild. This is the focus on this paper: we analyze 164 billion queries/response pairs from more than 46k autonomous systems, covering three months (July 2019 and 2020, and Oct. 2020), collected at the authoritative servers of the.nl, the country-code top-level domain of the Netherlands. We show that fragmentation, and the problems that can follow fragmentation, rarely occur at such authoritative servers. Further, we demonstrate that DNS built-in defenses – use of truncation, EDNS0 buffer sizes, reduced responses and TCP fall back – are effective to reduce fragmentation. Last, we measure the uptake of the DNS flag day in 2020.</p
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