Pre-Congestion Notification (PCN) Architecture

This document describes a general architecture for flow admission and termination based on pre-congestion information in order to protect the quality of service of established, inelastic flows within a single Diffserv domain.\u

End-To-End Microflow Performance Measurement of IPv6 Traffic Over Diverse Wireless Topologies

In order to facilitate resource accountability in environments with rapidly and unpredictably evolving traffic dynamics, it is of key importance to develop mechanisms capable of ubiquitously measuring different performance aspects of the diverse operational network traffic. In this work, we used an IPv6-based measurement mechanism to assess the end-to-end performance experienced by a set of IPv6 microflows as these were routed over operational W-LAN and W-WAN network configurations. We present measurements of unidirectional delay and packet loss experienced by bulk TCP and CBR UDP traffic during different days of the week

Journal of Telecommunications and Information Technology, 2003, nr 2

kwartalni

Deux défis des Réseaux Logiciels : Relayage par le Nom et Vérification des Tables

The Internet changed the lives of network users: not only it affects users' habits, but it is also increasingly being shaped by network users' behavior.Several new services have been introduced during the past decades (i.e. file sharing, video streaming, cloud computing) to meet users' expectation.As a consequence, although the Internet infrastructure provides a good best-effort service to exchange information in a point-to-point fashion, this is not the principal need that todays users request. Current networks necessitate some major architectural changes in order to follow the upcoming requirements, but the experience of the past decades shows that bringing new features to the existing infrastructure may be slow.In this thesis work, we identify two main aspects of the Internet evolution: a “behavioral” aspect, which refers to a change occurred in the way users interact with the network, and a “structural” aspect, related to the evolution problem from an architectural point of view.The behavioral perspective states that there is a mismatch between the usage of the network and the actual functions it provides. While network devices implement the simple primitives of sending and receiving generic packets, users are really interested in different primitives, such as retrieving or consuming content. The structural perspective suggests that the problem of the slow evolution of the Internet infrastructure lies in its architectural design, that has been shown to be hardly upgradeable.On the one hand, to encounter the new network usage, the research community proposed the Named-data networking paradigm (NDN), which brings the content-based functionalities to network devices.On the other hand Software-defined networking (SDN) can be adopted to simplify the architectural evolution and shorten the upgrade-time thanks to its centralized software control plane, at the cost of a higher network complexity that can easily introduce some bugs. SDN verification is a novel research direction aiming to check the consistency and safety of network configurations by providing formal or empirical validation.The talk consists of two parts. In the first part, we focus on the behavioral aspect by presenting the design and evaluation of “Caesar”, a content router that advances the state-of-the-art by implementing content-based functionalities which may coexist with real network environments.In the second part, we target network misconfiguration diagnosis, and we present a framework for the analysis of the network topology and forwarding tables, which can be used to detect the presence of a loop at real-time and in real network environments.Cette thèse aborde des problèmes liés à deux aspects majeurs de l’évolution d’Internet : l’aspect >, qui correspond aux nouvelles interactions entre les utilisateurs et le réseau, et l’aspect >, lié aux changements d’Internet d’un point de vue architectural.Le manuscrit est composé d’un chapitre introductif qui donne les grandes lignes de recherche de ce travail de thèse, suivi d’un chapitre consacré à la description de l’état de l’art sur les deux aspects mentionnés ci-dessus. Parmi les solutions proposées par la communauté scientifique pour s'adapter à l’évolution d’Internet, deux nouveaux paradigmes réseaux sont particulièrement décrits : Information- Centric Networking (ICN) et Software-Defined Networking (SDN).La thèse continue avec la proposition de >, un dispositif réseau, inspiré par ICN, capable de gérer la distribution de contenus à partir de primitives de routage basées sur le nom des données et non les adresses des serveurs. Caesar est présenté dans deux chapitres, qui décrivent l’architecture et deux des principaux modules : le relayage et la gestion de la traçabilité des requêtes.La suite du manuscrit décrit un outil mathématique pour la détection efficace de boucles dans un réseau SDN d’un point de vue théorique. Les améliorations de l’algorithme proposé par rapport à l’état de l’art sont discutées.La thèse se conclue par un résumé des principaux résultats obtenus et une présentation des travaux en cours et futurs