Since the early 2000’s, the Internet topology has been an attractive and important research topic... more Since the early 2000’s, the Internet topology has been an attractive and important research topic, either for developing data collection mechanisms, and for analyzing and modeling the network. Beside traditional aspects of the Internet topology (i.e., IP interface, router, and AS levels), recent researches focused on intermediate promising visions of the topology, namely Point-of-Presence (PoP) and subnets (i.e., a set of devices that are located on the same connection medium and that can communicate directly with each other at the link layer). This paper focuses on network subnet discovery by proposing a new tool called TreeNET. One of the key aspects of TreeNET is that it builds a tree representing the way subnets are located with respect to each other. This tree allows TreeNET to obtain additional information on the network, leading to better analysis of the collected data. In this paper, we demonstrate the potential of TreeNET through the evaluation of its key algorithmic steps ...
This paper addresses a remote teaching activity that consists, for students, in being exposed to ... more This paper addresses a remote teaching activity that consists, for students, in being exposed to podcasts instead of classic face-to-face theoretical lessons. In particular, the paper discusses potential impact of podcasts on students’ engagement in an introductory Computer Science course.
ABSTRACT Active and passive measurements for topology dis-covery have known an impressive growth ... more ABSTRACT Active and passive measurements for topology dis-covery have known an impressive growth during the last decade. While a lot of work has been done regarding inter-domain topol-ogy discovery and modeling, only a few papers raise the question of how to extract intra-domain topologies from measurements results. In this paper, based on a large dataset collected with mrinfo, a multicast tool that silently discovers all interfaces of a router, we propose a method to retrieve intra-domain topologies. The main challenge is to assign an AS number to a border router whose IP addresses are not mapped to the same AS. Our algorithm is based on probabilistic and empirical IP allocation rules. The goal of our pool of rules is to converge to a consistent router to AS mapping. We show that our router to AS algorithm is efficient in more than 99% of the cases. Furthermore, with mrinfo, point-to-point links can be distinguished from multiple links attached to a switch, providing an accurate view of the collected topologies. We provide a set of large topologies in various formats. In addition, we experimentally demonstrate that the node degree distribution is strongly impacted by the presence of layer-2 (L2) hardware, such as switch.
Proceedings of the 2020 ACM Conference on International Computing Education Research
This abstract focuses on a CS2 course in which gamified homework exercises are provided to studen... more This abstract focuses on a CS2 course in which gamified homework exercises are provided to students instead of in-class exercise sessions. The course, provided to first-year Computer Science students, introduces a rigorous methodology to write programs using Loop Invariants, recursion, and basic data structures such as Files, Lists, Queues, and Stacks. In early 2020, the COVID-19 pandemic caused a lock-down in our country. The universities decided to fully switch to remote teaching. As the exercises sessions previously consisted of solving problems on a blackboard, we had to design in a hurry course materials that would cope with remote teaching. Instead of giving students yet another podcast in their course schedule, we gave them homework exercises, we called GameCode, that they could do at their own convenience. These exercises are inspired by GameBooks in which the reader can choose the path she takes to complete the story. With GameCode, students can choose their own solving path for each exercise. This can be related to gamification.
Proceedings of the Workshop on Big Data Analytics and Machine Learning for Data Communication Networks
We study the problem of predicting Internet path changes and path performance using traceroute me... more We study the problem of predicting Internet path changes and path performance using traceroute measurements and machine learning models. Path changes are frequently linked to path in ation and performance degradation, therefore the relevance of the problem. We introduce NETPerfTrace, an Internet Path Tracking system to forecast path changes and path latency variations. By relying on decision trees and using empirical distribution-based input features, we show that NETPerfTrace can predict (i) the remaining life time of a path before it actually changes and (ii) the number of path changes in a certain time period with relatively high accuracy. Through extensive evaluation, we demonstrate that NET-PerfTrace highly outperforms DTRACK, a previous system with the same prediction targets. NETPerfTrace also o ers path performance forecasting capabilities. In particular, our tool can predict path latency metrics, providing a system which can not only predict path changes, but also forecast their impact in terms of performance variations. We release NETPerfTrace as open software to the networking community, as well as all evaluation datasets. CCS CONCEPTS • Networks → Network performance modeling; • Computing methodologies → Supervised learning by regression; Feature selection;
Recent years have seen the rise of middleboxes, such as firewalls, NATs, proxies, or Deep Packet ... more Recent years have seen the rise of middleboxes, such as firewalls, NATs, proxies, or Deep Packet Inspectors. Those middleboxes play an important role in today’s Internet, including enterprise networks and cellular networks. However, despite their huge success in modern network architecture, their actual impact on packets, traffic, or network performance (all in IPv4 and IPv6 networks) is not that much understood. In this paper, we propose a path impairment oriented middlebox classification that aims at categorizing the initial purpose of a middlebox policy as well as its potential unexpected complications.
La plupart des programmes nécessitent l’élaboration d’une séquence d’instructions répétées un cer... more La plupart des programmes nécessitent l’élaboration d’une séquence d’instructions répétées un certain nombre de fois, appelée généralement « boucle ». La méthodologie de développement de programmes que nous privilégions est basée sur le concept d’Invariant de boucle introduit par Hoare (Hoare, 1969). Cette méthodologie consiste à déterminer la stratégie de résolution du problème, préalablement à toute écriture de code. C’est une phase de réflexion, plutôt abstraite, qui demande de s’exercer régulièrement sur des problèmes de difficulté croissante pour être maitrisée. Néanmoins, cela permet de réduire les erreurs de programmation. La notion d’Invariant de boucle permet, par ailleurs, d’assurer qu’un algorithme est correct (Cormen et al., 2009).
This deliverable is part of WP3 (Cognitive network and system experimentation). The feasibility, ... more This deliverable is part of WP3 (Cognitive network and system experimentation). The feasibility, benefits and applicability of introducing a cognitive engine in the ECODE architecture are experimented using a number of use cases covering different problem areas identified as Internet architectural and design challenges. In particular we address techniques for path availability estimation, for improving network recovery and resiliency, and profile-based accountability. The following three use cases are studied in-depth: � Path availability: the goal is to design and experiment techniques, embedded in our so-called IDIPS server, to rank internet paths based on their characteristics, such as delays, and available throughput. To this end, on-line machine learning techniques are used to estimate future path characteristics based on past measurements, in order to reduce the future measurement load. Machine learning techniques are also used to Improve Internet Coordinate Systems to better ...
This deliverable is part of WP3 (Cognitive network and system experimentation). The feasibility, ... more This deliverable is part of WP3 (Cognitive network and system experimentation). The feasibility, benefits and applicability of introducing a cognitive engine in the ECODE architecture are experimented using a number of use cases covering different problem areas identified as Internet architectural and design challenges. In particular we address techniques for path availability estimation, for improving network recovery and resiliency, and profile-based accountability. The following three use cases are studied in depth: � Path availability: the goal is to design and experiment techniques, embedded in our so-called IDIPS server, to rank internet paths based on their characteristics, such as delays, and available throughput. To this end, on-line machine learning techniques are used to estimate future path characteristics based on past measurements, in order to reduce the future measurement load. Machine learning techniques are also used to Improve Internet Coordinate Systems to better ...
IEEE Journal on Selected Areas in Communications, 2006
Topology discovery systems are starting to be introduced in the form of easily and widely deploye... more Topology discovery systems are starting to be introduced in the form of easily and widely deployed software. Unfortunately, the research community has not examined the problem of how to perform such measurements efficiently and in a network-friendly manner. This paper describes several contributions towards that end. These were first presented in the proceedings of ACM SIGMETRICS 2005. We show that standard topology discovery methods (e.g., skitter) are quite inefficient, repeatedly probing the same interfaces. This is a concern, because when scaled up, such methods will generate so much traffic that they will begin to resemble DDoS attacks. We propose two metrics focusing on redundancy in probing and show that both are important. We also propose and evaluate Doubletree, an algorithm that strongly reduces redundancy while maintaining nearly the same level of node and link coverage. The key ideas are to exploit the tree-like structure of routes to and from a single point in order to guide when to stop probing, and to probe each path by starting near its midpoint. Following the SIGMETRICS work, we implemented Doubletree, and deployed it in a real network environment. This paper describes that implementation, as well as preliminary favorable results.
On February 8-10, 2010, CAIDA hosted the second Workshop on Active Internet Measurements (AIMS-2)... more On February 8-10, 2010, CAIDA hosted the second Workshop on Active Internet Measurements (AIMS-2) as part of our series of Internet Statistics and Metrics Analysis (ISMA) workshops. The goals of this workshop were to further our understanding of the potential and limitations of active measurement research and infrastructure in the wide-area Internet, and to promote cooperative solutions and coordinated strategies to addressing future data needs of the network and security research communities. The three-day workshop included presentations, group discussion and analysis, and focused interaction between participating researchers, operators, and policymakers from all over the world. This report describes the motivation and findings of the workshop, and reviews progress on recommendations developed at the 1st Active Internet Measurements Workshop in 2009 [18]. Slides from the workshop presentations are available at [9].
Topology discovery systems are starting to be introduced in the form of easily and widely deploye... more Topology discovery systems are starting to be introduced in the form of easily and widely deployed software. Scriptroute, for instance, provides a public infrastructure that anyone can use to conduct a wide range of active measurements from monitors deployed on PlanetLab [6] nodes. Also, DIMES [7] is a daemon that thousands of users have downloaded; it performs route traces and pings. The existence of such facilities raises the question of how to perform such measurements efficiently and in a networkfriendly manner. Both systems ...
Abstract—Today, PlanetLab [1] provides limited facilities to make applications aware of the under... more Abstract—Today, PlanetLab [1] provides limited facilities to make applications aware of the underlying network. The European Commission funded OneLab project [2] aims at building a sophisticated monitoring system allowing to get a view of the network topology and allowing applications to query this view. In order to deepen the current PlanetLab monitoring capabilities, we are proposing the addition of an always-running measurement service providing to any application a dedicated service that replies to specific queries on network ...
The IEEE 802.16 protocol, also known as WiMAX, has been designed to support long-range communicat... more The IEEE 802.16 protocol, also known as WiMAX, has been designed to support long-range communications with high bitrates, using two operation modes: Point-to-Multi-Point (PMP) and Mesh. In the mesh mode, Subscriber Stations (SSs) can directly communicate with each other, thus forming a tree, and can be used to forward other's data packets in a multihop fashion. On the contrary, in the PMP mode only one hop communication toward the Base Station (BS) is allowed. In this paper, we investigate the performance of the mesh mode by proposing an algorithm for constructing the WiMAX mesh tree. Our algorithm increases routes' effective throughput by splitting long links into multiple shorter ones. We show through simulations that this approach leads to improving the throughput capacity of WiMAX-based wireless mesh networks.
Proceedings of the 9th ACM SIGCOMM conference on Internet measurement conference - IMC '09, 2009
Redundant connectivity (or multiconnectivity) between adjacent autonomous systems (ASes) is impor... more Redundant connectivity (or multiconnectivity) between adjacent autonomous systems (ASes) is important for interdomain traffic engineering and fast recovery in case of failures. However, the redundancy of ASes business relationship links has not been quantitatively studied, mainly due to the difficulty of obtaining relevant data. In this paper, we show that the mrinfo multicast monitoring tool can provide useful data about the Internet topology and such redundant links in particular. Our analysis relies on more than four years of daily queries to about ten thousand routers mapped into more than two hundred ASes. We demonstrate that peering links between ASes are frequently redundant. In particular, our analysis shows that more than half of the studied ASes pairs are connected through multiple physical links. We then refine our analysis by considering the different types of ASes and their business relationships. A particular result of our analysis is that at least 75% of the peer-to-peer relationships between adjacent Tier-1 ASes are redundant, i.e., the connections between these ASes involve several physical links. Our analysis is conservative, providing so a lower bound, as some links might not be seen by mrinfo due to ISPs filtering policies.
Active and passive measurements for topology discovery have known an impressive growth during the... more Active and passive measurements for topology discovery have known an impressive growth during the last decade. If a lot of work has been done regarding inter-domain topology discovery and modeling, only a few papers raise the question of how to extract intra-domain topologies from measurements results. In this paper, based on a large dataset collected with mrinfo, a multicast tool that silently discovers all interfaces of a router, we provide a mechanism for retrieving intra-domain topologies. The main challenge is to assign an AS number to a border router whose IP addresses are not mapped to the same AS. Our algorithm is based on probabilistic and empirical IP allocation rules. The goal of our pool of rules is to converge to a consistent router to AS mapping. We show that our router-to-AS algorithm results in a mapping in more than 99% of the cases. Furthermore, with mrinfo, point-to-point links between routers can be distinguished from multiple links attached to a switch, providing an accurate view of the collected topologies. Finally, we provide a set of large intra-domain topologies in various formats. ⋆ This work is partially funded by the European Commission funded Trilogy ICT-216372 project. B. Donnet's work is supported by the FNRS/FRS (Fonds National de la Recherche Scientifique, rue d'Egmont 5-1000 Bruxelles, Belgium.). network. Obtaining complete intra-domain topologies is further a daunting task, requiring extensive probing campaigns [3]. Recently, we used mrinfo [4], a management multicast tool, in order to collect topology information [5]. mrinfo has the advantage of sweeping out many of traceroute's limitations as it is able to silently discover all interfaces of a router. However, it requires multicast being enable within ISPs' networks and no filtering policies, limiting so its applicability range. Indeed, only IPv4 multicast enabled routers reply to mrinfo. Also, some ISPs filter the IGMP messages used by mrinfo (i.e., they do not propagate them). In this paper, we take advantage of the mrinfo dataset [6] for extracting intradomain router level topologies. Obtaining real data concerning intra-domain topologies is of the highest importance. Indeed, it allows one to study actual network characteristics (e.g, degree distribution, network connectivity,. . .) and to obtain insights on the way operators build their network. Furthermore, real topologies are crucial inputs for network simulations in order to consider complex and realistic scenarios. By modeling the collected topologies characteristics, it can also contribute to building better topology generators. The contributions of this paper are twofold. We first describe how to extract intra-domain topologies from raw mrinfo data. While it is pretty easy to map IP addresses to an autonomous system number (ASN), the challenge is to mark the boundary of a given autonomous system (AS). Then, it is necessary to assign the right ASN to an AS border router (ASBR) whose IP addresses are not mapped to a single AS. In this paper, we provide an efficient algorithm, called routerto-AS mapping, for fixing this issue. We evaluate our algorithm and show that it provides a consistent mapping in more than 99.5% of the cases. In addition, an interesting feature of mrinfo is that point-to-point links between routers may be distinguished from multiple links attached to a switch. On average, we discover that roughly 11% of the nodes, in probed networks, are actually switches. As depicted in Sec. 3, this is a fundamental issue to correctly analyze network characteristics. Second, based on our router-to-AS mapping, we provide a set of intra-domain topologies under various formats. Our set of topologies is composed of three kind of networks: Tier-1 (such as Sprint), Transit networks (such as TDC), and Stub networks (such as UNINETT). 3 An extended version of this paper provides more results and discussions [7]. The remainder of this paper is organized as follows: Sec. 2 discusses how we collected topology data using mrinfo; Sec. 3 explains and evaluates our routerto-AS algorithm; Sec. 4 positions our work regarding the state of the art; Finally, Sec. 5 concludes this paper by summarizing its main achievements and discussing further works. 2 Collection Methodology and Dataset mrinfo messages use the Internet Group Management Protocol (IGMP [8]). IGMP was initially designed to allow hosts to report their active multicast groups
2012 IEEE Global Communications Conference (GLOBECOM), 2012
Recent developments in router level topology discovery have suggested the introduction of IGMP pr... more Recent developments in router level topology discovery have suggested the introduction of IGMP probing in addition to standard techniques such as traceroute and alias resolution. With a single IGMP probe, one can obtain all multicast interfaces and links of a multicast router. If such a probing is a promising approach, we noticed that IGMP probes are subject to filtering, leading so to the fragmentation of the collected multicast graph into several disjoint connected components. In this paper, we cope with the fragmentation issue. Our contributions are threefold: (i) we experimentally quantify the damages caused by IGMP filtering on collected topologies of large tier-1 ISPs; (ii) using traceroute data, we construct a hybrid graph and estimate how far each IGMP fragment is from each other; (iii) we provide and experimentally evaluate a recursive approach for reconnecting disjoint multicast components. The key idea of the third contribution is to recursively apply alias resolution to reassemble disjoint fragments and, thus, progressively extend the mapping of the targeted ISP. Data presented in the paper, as well as reconstructed topologies, are freely available at http://svnet.u-strasbg.fr/merlin.
Proceedings of the 2013 conference on Internet measurement conference, 2013
The paper is well motivated, and I can imagine using it. Paths are complicated, middleboxes can c... more The paper is well motivated, and I can imagine using it. Paths are complicated, middleboxes can cause various behaviors, and traceroute is widely used: A traceroute-like tool to expose the complexity and middlebox behavior would be very useful. The initial steps towards a tool, which is capable of revealing middleboxes on a path, are promising.
Proceedings of the 22nd ACM Internet Measurement Conference
Researchers often face the lack of data on large operational networks to understand how they are ... more Researchers often face the lack of data on large operational networks to understand how they are used, how they behave, and sometimes how they fail. This data is crucial to drive the evolution of Internet protocols and develop techniques such as traffic engineering, DDoS detection and mitigation. Companies that have access to measurements from operational networks and services leverage this data to improve the availability, speed, and resilience of their Internet services. Unfortunately, the availability of large datasets, especially collected regularly over a long period of time, is a daunting task that remains scarce in the literature. We tackle this problem by releasing a dataset collected over roughly two years of observations of a major cloud company (OVH). Our dataset, called OVH Weather dataset, represents the evolution of more than 180 routers, 1,100 internal links, 500 external links, and their load percentages in the backbone network over time. Our dataset has a high density with snapshots taken every five minutes, totaling more than 500,000 files. In this paper, we also illustrate how our dataset could be used to study the backbone networks evolution. Finally, our dataset opens several exciting research questions that we make available to the research community. CCS CONCEPTS • Networks → Network measurement; Data center networks.
Since the early 2000’s, the Internet topology has been an attractive and important research topic... more Since the early 2000’s, the Internet topology has been an attractive and important research topic, either for developing data collection mechanisms, and for analyzing and modeling the network. Beside traditional aspects of the Internet topology (i.e., IP interface, router, and AS levels), recent researches focused on intermediate promising visions of the topology, namely Point-of-Presence (PoP) and subnets (i.e., a set of devices that are located on the same connection medium and that can communicate directly with each other at the link layer). This paper focuses on network subnet discovery by proposing a new tool called TreeNET. One of the key aspects of TreeNET is that it builds a tree representing the way subnets are located with respect to each other. This tree allows TreeNET to obtain additional information on the network, leading to better analysis of the collected data. In this paper, we demonstrate the potential of TreeNET through the evaluation of its key algorithmic steps ...
This paper addresses a remote teaching activity that consists, for students, in being exposed to ... more This paper addresses a remote teaching activity that consists, for students, in being exposed to podcasts instead of classic face-to-face theoretical lessons. In particular, the paper discusses potential impact of podcasts on students’ engagement in an introductory Computer Science course.
ABSTRACT Active and passive measurements for topology dis-covery have known an impressive growth ... more ABSTRACT Active and passive measurements for topology dis-covery have known an impressive growth during the last decade. While a lot of work has been done regarding inter-domain topol-ogy discovery and modeling, only a few papers raise the question of how to extract intra-domain topologies from measurements results. In this paper, based on a large dataset collected with mrinfo, a multicast tool that silently discovers all interfaces of a router, we propose a method to retrieve intra-domain topologies. The main challenge is to assign an AS number to a border router whose IP addresses are not mapped to the same AS. Our algorithm is based on probabilistic and empirical IP allocation rules. The goal of our pool of rules is to converge to a consistent router to AS mapping. We show that our router to AS algorithm is efficient in more than 99% of the cases. Furthermore, with mrinfo, point-to-point links can be distinguished from multiple links attached to a switch, providing an accurate view of the collected topologies. We provide a set of large topologies in various formats. In addition, we experimentally demonstrate that the node degree distribution is strongly impacted by the presence of layer-2 (L2) hardware, such as switch.
Proceedings of the 2020 ACM Conference on International Computing Education Research
This abstract focuses on a CS2 course in which gamified homework exercises are provided to studen... more This abstract focuses on a CS2 course in which gamified homework exercises are provided to students instead of in-class exercise sessions. The course, provided to first-year Computer Science students, introduces a rigorous methodology to write programs using Loop Invariants, recursion, and basic data structures such as Files, Lists, Queues, and Stacks. In early 2020, the COVID-19 pandemic caused a lock-down in our country. The universities decided to fully switch to remote teaching. As the exercises sessions previously consisted of solving problems on a blackboard, we had to design in a hurry course materials that would cope with remote teaching. Instead of giving students yet another podcast in their course schedule, we gave them homework exercises, we called GameCode, that they could do at their own convenience. These exercises are inspired by GameBooks in which the reader can choose the path she takes to complete the story. With GameCode, students can choose their own solving path for each exercise. This can be related to gamification.
Proceedings of the Workshop on Big Data Analytics and Machine Learning for Data Communication Networks
We study the problem of predicting Internet path changes and path performance using traceroute me... more We study the problem of predicting Internet path changes and path performance using traceroute measurements and machine learning models. Path changes are frequently linked to path in ation and performance degradation, therefore the relevance of the problem. We introduce NETPerfTrace, an Internet Path Tracking system to forecast path changes and path latency variations. By relying on decision trees and using empirical distribution-based input features, we show that NETPerfTrace can predict (i) the remaining life time of a path before it actually changes and (ii) the number of path changes in a certain time period with relatively high accuracy. Through extensive evaluation, we demonstrate that NET-PerfTrace highly outperforms DTRACK, a previous system with the same prediction targets. NETPerfTrace also o ers path performance forecasting capabilities. In particular, our tool can predict path latency metrics, providing a system which can not only predict path changes, but also forecast their impact in terms of performance variations. We release NETPerfTrace as open software to the networking community, as well as all evaluation datasets. CCS CONCEPTS • Networks → Network performance modeling; • Computing methodologies → Supervised learning by regression; Feature selection;
Recent years have seen the rise of middleboxes, such as firewalls, NATs, proxies, or Deep Packet ... more Recent years have seen the rise of middleboxes, such as firewalls, NATs, proxies, or Deep Packet Inspectors. Those middleboxes play an important role in today’s Internet, including enterprise networks and cellular networks. However, despite their huge success in modern network architecture, their actual impact on packets, traffic, or network performance (all in IPv4 and IPv6 networks) is not that much understood. In this paper, we propose a path impairment oriented middlebox classification that aims at categorizing the initial purpose of a middlebox policy as well as its potential unexpected complications.
La plupart des programmes nécessitent l’élaboration d’une séquence d’instructions répétées un cer... more La plupart des programmes nécessitent l’élaboration d’une séquence d’instructions répétées un certain nombre de fois, appelée généralement « boucle ». La méthodologie de développement de programmes que nous privilégions est basée sur le concept d’Invariant de boucle introduit par Hoare (Hoare, 1969). Cette méthodologie consiste à déterminer la stratégie de résolution du problème, préalablement à toute écriture de code. C’est une phase de réflexion, plutôt abstraite, qui demande de s’exercer régulièrement sur des problèmes de difficulté croissante pour être maitrisée. Néanmoins, cela permet de réduire les erreurs de programmation. La notion d’Invariant de boucle permet, par ailleurs, d’assurer qu’un algorithme est correct (Cormen et al., 2009).
This deliverable is part of WP3 (Cognitive network and system experimentation). The feasibility, ... more This deliverable is part of WP3 (Cognitive network and system experimentation). The feasibility, benefits and applicability of introducing a cognitive engine in the ECODE architecture are experimented using a number of use cases covering different problem areas identified as Internet architectural and design challenges. In particular we address techniques for path availability estimation, for improving network recovery and resiliency, and profile-based accountability. The following three use cases are studied in-depth: � Path availability: the goal is to design and experiment techniques, embedded in our so-called IDIPS server, to rank internet paths based on their characteristics, such as delays, and available throughput. To this end, on-line machine learning techniques are used to estimate future path characteristics based on past measurements, in order to reduce the future measurement load. Machine learning techniques are also used to Improve Internet Coordinate Systems to better ...
This deliverable is part of WP3 (Cognitive network and system experimentation). The feasibility, ... more This deliverable is part of WP3 (Cognitive network and system experimentation). The feasibility, benefits and applicability of introducing a cognitive engine in the ECODE architecture are experimented using a number of use cases covering different problem areas identified as Internet architectural and design challenges. In particular we address techniques for path availability estimation, for improving network recovery and resiliency, and profile-based accountability. The following three use cases are studied in depth: � Path availability: the goal is to design and experiment techniques, embedded in our so-called IDIPS server, to rank internet paths based on their characteristics, such as delays, and available throughput. To this end, on-line machine learning techniques are used to estimate future path characteristics based on past measurements, in order to reduce the future measurement load. Machine learning techniques are also used to Improve Internet Coordinate Systems to better ...
IEEE Journal on Selected Areas in Communications, 2006
Topology discovery systems are starting to be introduced in the form of easily and widely deploye... more Topology discovery systems are starting to be introduced in the form of easily and widely deployed software. Unfortunately, the research community has not examined the problem of how to perform such measurements efficiently and in a network-friendly manner. This paper describes several contributions towards that end. These were first presented in the proceedings of ACM SIGMETRICS 2005. We show that standard topology discovery methods (e.g., skitter) are quite inefficient, repeatedly probing the same interfaces. This is a concern, because when scaled up, such methods will generate so much traffic that they will begin to resemble DDoS attacks. We propose two metrics focusing on redundancy in probing and show that both are important. We also propose and evaluate Doubletree, an algorithm that strongly reduces redundancy while maintaining nearly the same level of node and link coverage. The key ideas are to exploit the tree-like structure of routes to and from a single point in order to guide when to stop probing, and to probe each path by starting near its midpoint. Following the SIGMETRICS work, we implemented Doubletree, and deployed it in a real network environment. This paper describes that implementation, as well as preliminary favorable results.
On February 8-10, 2010, CAIDA hosted the second Workshop on Active Internet Measurements (AIMS-2)... more On February 8-10, 2010, CAIDA hosted the second Workshop on Active Internet Measurements (AIMS-2) as part of our series of Internet Statistics and Metrics Analysis (ISMA) workshops. The goals of this workshop were to further our understanding of the potential and limitations of active measurement research and infrastructure in the wide-area Internet, and to promote cooperative solutions and coordinated strategies to addressing future data needs of the network and security research communities. The three-day workshop included presentations, group discussion and analysis, and focused interaction between participating researchers, operators, and policymakers from all over the world. This report describes the motivation and findings of the workshop, and reviews progress on recommendations developed at the 1st Active Internet Measurements Workshop in 2009 [18]. Slides from the workshop presentations are available at [9].
Topology discovery systems are starting to be introduced in the form of easily and widely deploye... more Topology discovery systems are starting to be introduced in the form of easily and widely deployed software. Scriptroute, for instance, provides a public infrastructure that anyone can use to conduct a wide range of active measurements from monitors deployed on PlanetLab [6] nodes. Also, DIMES [7] is a daemon that thousands of users have downloaded; it performs route traces and pings. The existence of such facilities raises the question of how to perform such measurements efficiently and in a networkfriendly manner. Both systems ...
Abstract—Today, PlanetLab [1] provides limited facilities to make applications aware of the under... more Abstract—Today, PlanetLab [1] provides limited facilities to make applications aware of the underlying network. The European Commission funded OneLab project [2] aims at building a sophisticated monitoring system allowing to get a view of the network topology and allowing applications to query this view. In order to deepen the current PlanetLab monitoring capabilities, we are proposing the addition of an always-running measurement service providing to any application a dedicated service that replies to specific queries on network ...
The IEEE 802.16 protocol, also known as WiMAX, has been designed to support long-range communicat... more The IEEE 802.16 protocol, also known as WiMAX, has been designed to support long-range communications with high bitrates, using two operation modes: Point-to-Multi-Point (PMP) and Mesh. In the mesh mode, Subscriber Stations (SSs) can directly communicate with each other, thus forming a tree, and can be used to forward other's data packets in a multihop fashion. On the contrary, in the PMP mode only one hop communication toward the Base Station (BS) is allowed. In this paper, we investigate the performance of the mesh mode by proposing an algorithm for constructing the WiMAX mesh tree. Our algorithm increases routes' effective throughput by splitting long links into multiple shorter ones. We show through simulations that this approach leads to improving the throughput capacity of WiMAX-based wireless mesh networks.
Proceedings of the 9th ACM SIGCOMM conference on Internet measurement conference - IMC '09, 2009
Redundant connectivity (or multiconnectivity) between adjacent autonomous systems (ASes) is impor... more Redundant connectivity (or multiconnectivity) between adjacent autonomous systems (ASes) is important for interdomain traffic engineering and fast recovery in case of failures. However, the redundancy of ASes business relationship links has not been quantitatively studied, mainly due to the difficulty of obtaining relevant data. In this paper, we show that the mrinfo multicast monitoring tool can provide useful data about the Internet topology and such redundant links in particular. Our analysis relies on more than four years of daily queries to about ten thousand routers mapped into more than two hundred ASes. We demonstrate that peering links between ASes are frequently redundant. In particular, our analysis shows that more than half of the studied ASes pairs are connected through multiple physical links. We then refine our analysis by considering the different types of ASes and their business relationships. A particular result of our analysis is that at least 75% of the peer-to-peer relationships between adjacent Tier-1 ASes are redundant, i.e., the connections between these ASes involve several physical links. Our analysis is conservative, providing so a lower bound, as some links might not be seen by mrinfo due to ISPs filtering policies.
Active and passive measurements for topology discovery have known an impressive growth during the... more Active and passive measurements for topology discovery have known an impressive growth during the last decade. If a lot of work has been done regarding inter-domain topology discovery and modeling, only a few papers raise the question of how to extract intra-domain topologies from measurements results. In this paper, based on a large dataset collected with mrinfo, a multicast tool that silently discovers all interfaces of a router, we provide a mechanism for retrieving intra-domain topologies. The main challenge is to assign an AS number to a border router whose IP addresses are not mapped to the same AS. Our algorithm is based on probabilistic and empirical IP allocation rules. The goal of our pool of rules is to converge to a consistent router to AS mapping. We show that our router-to-AS algorithm results in a mapping in more than 99% of the cases. Furthermore, with mrinfo, point-to-point links between routers can be distinguished from multiple links attached to a switch, providing an accurate view of the collected topologies. Finally, we provide a set of large intra-domain topologies in various formats. ⋆ This work is partially funded by the European Commission funded Trilogy ICT-216372 project. B. Donnet's work is supported by the FNRS/FRS (Fonds National de la Recherche Scientifique, rue d'Egmont 5-1000 Bruxelles, Belgium.). network. Obtaining complete intra-domain topologies is further a daunting task, requiring extensive probing campaigns [3]. Recently, we used mrinfo [4], a management multicast tool, in order to collect topology information [5]. mrinfo has the advantage of sweeping out many of traceroute's limitations as it is able to silently discover all interfaces of a router. However, it requires multicast being enable within ISPs' networks and no filtering policies, limiting so its applicability range. Indeed, only IPv4 multicast enabled routers reply to mrinfo. Also, some ISPs filter the IGMP messages used by mrinfo (i.e., they do not propagate them). In this paper, we take advantage of the mrinfo dataset [6] for extracting intradomain router level topologies. Obtaining real data concerning intra-domain topologies is of the highest importance. Indeed, it allows one to study actual network characteristics (e.g, degree distribution, network connectivity,. . .) and to obtain insights on the way operators build their network. Furthermore, real topologies are crucial inputs for network simulations in order to consider complex and realistic scenarios. By modeling the collected topologies characteristics, it can also contribute to building better topology generators. The contributions of this paper are twofold. We first describe how to extract intra-domain topologies from raw mrinfo data. While it is pretty easy to map IP addresses to an autonomous system number (ASN), the challenge is to mark the boundary of a given autonomous system (AS). Then, it is necessary to assign the right ASN to an AS border router (ASBR) whose IP addresses are not mapped to a single AS. In this paper, we provide an efficient algorithm, called routerto-AS mapping, for fixing this issue. We evaluate our algorithm and show that it provides a consistent mapping in more than 99.5% of the cases. In addition, an interesting feature of mrinfo is that point-to-point links between routers may be distinguished from multiple links attached to a switch. On average, we discover that roughly 11% of the nodes, in probed networks, are actually switches. As depicted in Sec. 3, this is a fundamental issue to correctly analyze network characteristics. Second, based on our router-to-AS mapping, we provide a set of intra-domain topologies under various formats. Our set of topologies is composed of three kind of networks: Tier-1 (such as Sprint), Transit networks (such as TDC), and Stub networks (such as UNINETT). 3 An extended version of this paper provides more results and discussions [7]. The remainder of this paper is organized as follows: Sec. 2 discusses how we collected topology data using mrinfo; Sec. 3 explains and evaluates our routerto-AS algorithm; Sec. 4 positions our work regarding the state of the art; Finally, Sec. 5 concludes this paper by summarizing its main achievements and discussing further works. 2 Collection Methodology and Dataset mrinfo messages use the Internet Group Management Protocol (IGMP [8]). IGMP was initially designed to allow hosts to report their active multicast groups
2012 IEEE Global Communications Conference (GLOBECOM), 2012
Recent developments in router level topology discovery have suggested the introduction of IGMP pr... more Recent developments in router level topology discovery have suggested the introduction of IGMP probing in addition to standard techniques such as traceroute and alias resolution. With a single IGMP probe, one can obtain all multicast interfaces and links of a multicast router. If such a probing is a promising approach, we noticed that IGMP probes are subject to filtering, leading so to the fragmentation of the collected multicast graph into several disjoint connected components. In this paper, we cope with the fragmentation issue. Our contributions are threefold: (i) we experimentally quantify the damages caused by IGMP filtering on collected topologies of large tier-1 ISPs; (ii) using traceroute data, we construct a hybrid graph and estimate how far each IGMP fragment is from each other; (iii) we provide and experimentally evaluate a recursive approach for reconnecting disjoint multicast components. The key idea of the third contribution is to recursively apply alias resolution to reassemble disjoint fragments and, thus, progressively extend the mapping of the targeted ISP. Data presented in the paper, as well as reconstructed topologies, are freely available at http://svnet.u-strasbg.fr/merlin.
Proceedings of the 2013 conference on Internet measurement conference, 2013
The paper is well motivated, and I can imagine using it. Paths are complicated, middleboxes can c... more The paper is well motivated, and I can imagine using it. Paths are complicated, middleboxes can cause various behaviors, and traceroute is widely used: A traceroute-like tool to expose the complexity and middlebox behavior would be very useful. The initial steps towards a tool, which is capable of revealing middleboxes on a path, are promising.
Proceedings of the 22nd ACM Internet Measurement Conference
Researchers often face the lack of data on large operational networks to understand how they are ... more Researchers often face the lack of data on large operational networks to understand how they are used, how they behave, and sometimes how they fail. This data is crucial to drive the evolution of Internet protocols and develop techniques such as traffic engineering, DDoS detection and mitigation. Companies that have access to measurements from operational networks and services leverage this data to improve the availability, speed, and resilience of their Internet services. Unfortunately, the availability of large datasets, especially collected regularly over a long period of time, is a daunting task that remains scarce in the literature. We tackle this problem by releasing a dataset collected over roughly two years of observations of a major cloud company (OVH). Our dataset, called OVH Weather dataset, represents the evolution of more than 180 routers, 1,100 internal links, 500 external links, and their load percentages in the backbone network over time. Our dataset has a high density with snapshots taken every five minutes, totaling more than 500,000 files. In this paper, we also illustrate how our dataset could be used to study the backbone networks evolution. Finally, our dataset opens several exciting research questions that we make available to the research community. CCS CONCEPTS • Networks → Network measurement; Data center networks.
Since the early 2000’s, the Internet topology has been an attractive and important research topic... more Since the early 2000’s, the Internet topology has been an attractive and important research topic, either for developing data collection mechanisms, and for analyzing and modeling the network. Beside traditional aspects of the Internet topology (i.e., IP interface, router, and AS levels), recent researches focused on intermediate promising visions of the topology, namely Point-of-Presence (PoP) and subnets (i.e., a set of devices that are located on the same connection medium and that can communicate directly with each other at the link layer). This paper focuses on network subnet discovery by proposing a new tool called TreeNET. One of the key aspects of TreeNET is that it builds a tree representing the way subnets are located with respect to each other. This tree allows TreeNET to obtain additional information on the network, leading to better analysis of the collected data. In this paper, we demonstrate the potential of TreeNET through the evaluation of its key algorithmic steps and the study of measurements collected from the PlanetLab testbed.
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Papers by Benoit Donnet
This paper focuses on network subnet discovery by proposing a new tool called TreeNET. One of the key aspects of TreeNET is that it builds a tree representing the way subnets are located with respect to each other. This tree allows TreeNET to obtain additional information on the network, leading to better analysis of the collected data. In this paper, we demonstrate the potential of TreeNET through the evaluation of its key algorithmic steps and the study of measurements collected from the PlanetLab testbed.