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.
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 ...
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 ...
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.
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 ...
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 ...
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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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.