Teses / dissertações sobre o tema "Content Centric Networking (CCN)"

Les ressources d'un réseau informatique sont partagées par un grand nombre d'utilisateurs, le réseau peut devenir congestionné voire saturé. Le contrôle de congestion est un élément critique garantissant son bon fonctionnement. Encore récemment, les problématiques d'ingénierie de trafic et de QoS n'étaient pas explorées dans le cadre des réseaux CCN (Content-Centric Networking).L'objectif de cette thèse consiste à évaluer l'impact de la congestion dans CCN, à concevoir un mécanisme de contrôle de congestion et à en évaluer l'efficacité.Nous avons réalisé une telle solution en deux temps. D'une part, nous proposons le mécanisme HoBHIS qui repose sur l'équilibrage de flot définie dans CCN. Ce mécanisme, déployé sur chaque routeur CCN, consiste à surveiller les échanges réalisés sur un même tampon de transmission. Il contrôle dynamiquement le taux d'envoi des demandes de contenu afin de garantir qu'au niveau du goulot d'étranglement, la taille de la file d'attente des paquets de donnée correspondante tende vers un seuil préconfiguré. D'autre part, nous proposons un mécanisme contrôlant le débit d'envoi d'un client afin d'éviter une congestion des files d'attente des noeuds CCN impliqués dans la communication.Nous avons prouvé mathématiquement l'efficacité de nos mécanismes et évalué leur performance à l'aide du simulateur ndnSIM.Les résultats de notre travail sont publiés dans des conférences internationales renommées. Nous avons aussi collaboré avec Cisco Systems (Boston, USA), qui s'est intéressé à nos travaux. Les résultats issus de cette collaboration sont publiés dans un article international qui a reçu un "Best Paper Award" et sont présentés dans cette thèse
The network resources are shared between a large number of users. It may potentially create a risk for buffer overflow and performance degradation. That is why congestion control is critical to guarantee network performance. Congestion control schemes have been widely studied in the past but only recently in the context of CCN (Content-Centric Networking).This thesis explores the congestion control risk of CCN, identifies the bottlenecks and proposes strategies to circumvent them. We have designed our original hop-by-hop Interest shaping mechanism (HoBHIS) that nicely exploits the flow balance enforced in CCN between Interest and Chunk packets. It monitors active conversations sharing the transmission buffer of a CCN node face in order to dynamically adjust their Interest sending rate and enforce the Chunk queue length to converge to a defined objective. This mechanism is implemented in each CCN node. Then, we extended HoBHIS in order to address several important concerns that might occur in CCN. We proposed a Tolerance mechanism that controls the Clients sending rate as well as prevents the loss of Interest packets. We demonstrated the efficiency of our mechanisms through mathematical proofs and simulations performed in ndnSIM.Our results have been published in international conferences. The work has generated interest from the networking community. Particularly, "Cisco Systems" invited us to join their project on developing Named-Data Networking (NDN) traffic control mechanism. As one of the important results of this collaboration is a research article that got a SIGCOMM ICN workshop’13 “Best paper award”. This paper is also presented as a part of the dissertation

Les ressources d'un réseau informatique sont partagées par un grand nombre d'utilisateurs, le réseau peut devenir congestionné voire saturé. Le contrôle de congestion est un élément critique garantissant son bon fonctionnement. Encore récemment, les problématiques d'ingénierie de trafic et de QoS n'étaient pas explorées dans le cadre des réseaux CCN (Content-Centric Networking).L'objectif de cette thèse consiste à évaluer l'impact de la congestion dans CCN, à concevoir un mécanisme de contrôle de congestion et à en évaluer l'efficacité.Nous avons réalisé une telle solution en deux temps. D'une part, nous proposons le mécanisme HoBHIS qui repose sur l'équilibrage de flot définie dans CCN. Ce mécanisme, déployé sur chaque routeur CCN, consiste à surveiller les échanges réalisés sur un même tampon de transmission. Il contrôle dynamiquement le taux d'envoi des demandes de contenu afin de garantir qu'au niveau du goulot d'étranglement, la taille de la file d'attente des paquets de donnée correspondante tende vers un seuil préconfiguré. D'autre part, nous proposons un mécanisme contrôlant le débit d'envoi d'un client afin d'éviter une congestion des files d'attente des noeuds CCN impliqués dans la communication.Nous avons prouvé mathématiquement l'efficacité de nos mécanismes et évalué leur performance à l'aide du simulateur ndnSIM.Les résultats de notre travail sont publiés dans des conférences internationales renommées. Nous avons aussi collaboré avec Cisco Systems (Boston, USA), qui s'est intéressé à nos travaux. Les résultats issus de cette collaboration sont publiés dans un article international qui a reçu un "Best Paper Award" et sont présentés dans cette thèse
The network resources are shared between a large number of users. It may potentially create a risk for buffer overflow and performance degradation. That is why congestion control is critical to guarantee network performance. Congestion control schemes have been widely studied in the past but only recently in the context of CCN (Content-Centric Networking).This thesis explores the congestion control risk of CCN, identifies the bottlenecks and proposes strategies to circumvent them. We have designed our original hop-by-hop Interest shaping mechanism (HoBHIS) that nicely exploits the flow balance enforced in CCN between Interest and Chunk packets. It monitors active conversations sharing the transmission buffer of a CCN node face in order to dynamically adjust their Interest sending rate and enforce the Chunk queue length to converge to a defined objective. This mechanism is implemented in each CCN node. Then, we extended HoBHIS in order to address several important concerns that might occur in CCN. We proposed a Tolerance mechanism that controls the Clients sending rate as well as prevents the loss of Interest packets. We demonstrated the efficiency of our mechanisms through mathematical proofs and simulations performed in ndnSIM.Our results have been published in international conferences. The work has generated interest from the networking community. Particularly, "Cisco Systems" invited us to join their project on developing Named-Data Networking (NDN) traffic control mechanism. As one of the important results of this collaboration is a research article that got a SIGCOMM ICN workshop’13 “Best paper award”. This paper is also presented as a part of the dissertation

Today, computer networks are dominated by data distribution and content retrieval, but technology was created for communication between hosts. Content and service access requires mappnig between what users want and where in network it can be found. Content-centric networks separate content from its location. This thesis aims to security of Content-centric networks, looks for weak spots in its design and suggests steps for improvements of their security.

Content Centric Networking (CCN) est une architecture pour l'Internet du futur. CCN inclut des fonctionnalités de cache dans tous les noeuds du réseau. Son efficacité dépend largement de la performance de ses stratégies de cache. C'est pour cela que plusieurs études proposent des nouvelles stratégies de cache pour améliorer la performance d'un réseau CCN. Cependant parmi toutes ces stratégies, ce n'est pas évident de décider laquelle fonctionne le mieux. Il manque un environnement commun pour comparer ces stratégies. De plus, il n'est pas certain que ces approches soient les meilleures alternatives pour améliorer la performance du réseau. Dans cette thèse, on vise le problème de choisir les meilleures stratégies de caches pour CCN et les contributions sont les suivantes. On construit un environnement commun d'évaluation dans lequel on compare via simulation les stratégies de caches disponibles: Leave Copy Everywhere (LCE), Leave Copy Down (LCD), ProbCache, Cache "Less For More" et MAGIC. On analyse la performance de toutes ces stratégies et on décide la meilleure stratègie de cache pour chaque scénario. Ensuite, on propose deux stratégies de cache basées sur la popularité pour CCN. On commence avec un étude de la popularité de contenu et on présent la stratégie Most Popular Caching (MPC). MPC privilèges la distribution de contenu populaire dans les caches afin d'ameliorer les autres stratégies de cache. Dans une deuxième étape, on présent une stratègie de cache basé dans l'information des réseaux sociaux: Socially-Aware Caching Strategy (SACS). SACS privilèges la distribution de contenu publié par les utilisateurs les plus importantes
Content Centric Networking (CCN) is a new architecture for a future Internet. CCN includes in-network caching capabilities at every node. Its effciency depends drastically on performances of caching strategies. A lot of studies proposing new caching strategies to improve the performances of CCN. However, among all these strategies, it is still unclear which one performs better as there is a lack of common environment to compare these strategies. In this thesis, we address the challenge of selecting the best caching strategies for CCN. The contribution of this thesis are the following. We build a common evaluation scenario and we compare via simulation the state of the art caching strategies: Leave Copy Everywhere (LCE), Leave Copy Down (LCD), ProbCache, Cache "Less" For More and MAGIC. We analyze the performance of all the strategies in terms of Cache Hit, Stretch, Diversity and Complexity, and determine the cache strategy that fits the best with every scenario. Later on, we propose two novel caching strategies for CCN based on popularity. First, we study popularity of content and we present Most Popular Caching (MPC) strategy. MPC privileges distribution of popular caches into the caches and thus, it overcomes other caching strategies. Second, we present an alternative caching strategy based on social networks: Socially-Aware Caching Strategy (SACS). SACS privileges distribution of content published by influential users into the network. Both caching strategies overcome state of the art mechanisms and, to the best of our knowledge, we are the first to use social information to build caching strategies

Le volume de données échangées sur l'Internet a augmenté de façon spectaculaire au cours des dernières décennies. Le nombre croissant d'utilisateurs, d'appareils connectés et la popularité des contenus vidéo ont fait exploser la demande pour de nouvelles méthodes de communication capables de gérer le volume croissant des données. Les réseaux centrés sur l'information (Information Centric Networking, ICN) ont été proposés comme une alternative aux réseaux IP traditionnels. Dans les réseaux ICN, les consommateurs demandent au réseau un contenu par son nom via des paquets « intérêt », et reçoivent des données en réponse à leurs demandes sans avoir à se soucier de l'emplacement du contenu dans le réseau. Les réseaux ICN permettent la mise en cache dans le réseau et prennent naturellement en charge l'utilisation de chemins multiples. Néanmoins, le débit maximal ne peut être atteint que si le contenu est demandé sur un ensemble optimal d'arbres de multidiffusion. Le calcul de ces arbres de multidiffusion est difficile à mettre en œuvre sur de grands réseaux dynamiques et nécessite une coordination entre les entités du réseau. Le codage réseau (Network Coding) a été récemment introduit dans les réseaux ICN afin d'améliorer la diffusion par l'utilisation de chemins multiples et la mise en cache du contenu sans qu'une coordination soit nécessaire. Le défi dans le cas du codage réseau est d'obtenir un contenu codé linéairement indépendant en réponse à de multiples requêtes parallèles par un ou plusieurs consommateurs. Dans cette thèse, nous analysons certains travaux antérieurs qui intègrent le codage réseau et les réseaux ICN et identifions certains problèmes clés auxquels ils ont été confrontés. Nous proposons une solution efficace où les clients ajoutent des informations compactes aux paquets « intérêt » afin d'assurer l'indépendance linéaire du contenu codé. Cette thèse propose une architecture, MICN, qui intègre un codage réseau au-dessus d'une implémentation ICN basée sur les intérêts : Named Data Networking (NDN). L'architecture proposée permet de résoudre certains des problèmes rencontrés par les solutions ICN avec du codage réseau présentées dans le passé. Une nouvelle construction appelée MILIC (Multiple Interests for Linearly Independent Content) est introduite. Elle impose des contraintes sur la façon dont les réponses aux intérêts sont codées, dans le but d'obtenir des contenus linéairement indépendants en réponse à des intérêts multiples. L'analyse numérique et les simulations montrent que la construction MILIC fonctionne bien avec le codage réseau pour NDN, et que le protocole MICN offre un débit proche de l'optimum dans certains scénarios. Les performances du protocole MICN se comparent favorablement aux protocoles existants. Il présente des avantages significatifs lorsqu'on considère le nombre total de paquets transmis dans le réseau et dans le cas de liens pouvant subir des pertes. Plusieurs techniques de transport modifiées et intégrées dans le protocole MICN sont proposées afin d'optimiser l'utilisation des ressources du réseau tout en conservant un débit élevé. MILIC nous a aussi amené à considérer le problème de la construction de sous-ensembles de vecteurs dans un espace vectoriel donné, tels que lorsque l'on choisit arbitrairement un vecteur de chaque sous-ensemble, les vecteurs sélectionnés sont linéairement indépendants. Cette thèse le formalise comme un problème mathématique et étudie quelques solutions alternatives à la construction MILIC. Enfin, la thèse prouve qu'une large classe de solutions à ce problème est équivalente à MILIC
The amount of data exchanged over the Internet has grown drastically over the past decades. The increasing number of users, connected devices, and the popularity of video content have surged the demand for new communication methods that can deal with the growing volume of data traffic. Information-Centric Networking (ICN) has been proposed as an alternative to traditional IP-based networks. In ICN, consumers request named content via Interest packets to the network and receive data as a response to their request without taking care of the location of the content in the network. ICN allows in-network caching and naturally supports the use of multiple paths. Nevertheless, the maximum throughput can only be achieved if the content is requested over an optimal set of multicast trees. The computation of such multicast trees is hard to scale over large dynamic networks and requires coordination among network entities. Network coding has been recently introduced in ICN to improve multi-path dissemination and caching of content without the need for coordination. The challenge in the case of network coding is to get independent coded content in response to multiple parallel Interests by one or several consumers. In this thesis, we analyze some previous works that integrate network coding and ICN and identify some key issues these works face. We introduce an efficient solution where clients add compact information to Interest packets in order to ensure linear independence of content in network-coded ICN. This thesis proposes an architecture, MICN, that provides network coding on top of an Interest-based ICN implementation: Named Data Networking (NDN). The proposed architecture helps alleviate the issues faced by network coding-enabled ICN solutions presented in the past. A novel construction called MILIC (Multiple Interests for Linearly Independent Content) is introduced that imposes constraints on how the replies to Interests are coded, intending to get linearly independent contents in response to multiple Interests. Numerical analysis and simulations illustrate that the MILIC construction performs well with network-coded NDN, and the MICN protocol yields close to optimal throughput in some scenarios. The performance of MICN compares favorably to existing protocols. It shows significant benefits when considering the total number of transmitted packets in the network and in the case of lossy links. Several modified forwarding techniques integrated into the MICN protocol are proposed to optimize the network resource utilization while keeping a high throughput. MILIC led us to consider the problem of constructing subsets of vectors from a given vector space, such that when drawing arbitrarily one vector from each subset, the selected vectors are linearly independent. This thesis considers it as a mathematical problem and studies some alternative solutions to the MILIC construction. Finally, the thesis proves that a large family of solutions to this problem are equivalent to MILIC

Information Centric Network (ICN) architectures offer a viable design to cope with the disruptive nature of Challenged Network environments. They aim to address the challenges of unreliable connectivity and location transparency to offer a delay- and disruption-tolerant solution. Named Data Networking (NDN), a prominent ICN architecture, uses a publish/subscribe-driven model and relies on two main message units for communication, called Interests and Data. Instead of a host-based model for data retrieval, an addressing scheme based on named data is utilized. The naming of data allows for retrieval of data from the network without the knowledge of individual hosts. This thesis studies NDN behavior in a disruptive network environment. More specifically, we use CCNx as an implementation of a Content-Centric Networking protocol that inherits key characteristics from NDN. We study the behavior of CCNx using the Haggle testbed to simulate a simple disruptive network environment. We develop a delay/disruption-tolerant framework based on CCNx and implement the game Tic-Tac-Toe using that framework. The framework design is presented  with an analysis into various alternatives that were considered. A more complex five-node experiment with link disruption is performed using the framework to evaluate CCNx in a real world scenario. We conclude that CCNx is good at handling disruptions associated with Challenged Networks.

Content-Centric Networking (CCN) is a recently proposed networking architecture that can potentially lead to reduced bandwidth usage and better scalability and security as compared to the current IP-based architecture. In this thesis,we conduct a green analysis of content-centric networking and IP-based networking for a video streaming scenario.We consider two types of energy consumption: the energy required to manufacture the network devices and the energyrequired for operation. We perform simulations of content centric networking over three different network topologies (i.e., general tree, Content Distribution Network (CDN) tree and partial mesh) to assess the traffic rate reductions achieved by CCN's insertion of caches at routers. We generated two different types of traffic demands (Zipf and Uniformly distributed) to perform our analysis. Although CCN network devices have a higher intrinsic energy consumption compared to the IP-based devices because of the presence of additional memory, by exploiting their caching capabilities it is possible to reduce the overall energy consumption of the network. Content caching at the routers present on lower levels of the network (near clients) results in reducing traffic on the links which are close to the server (content source). We exploit this feature of CCN-based network by using rate adaptation to achieve energy benefits. We consider both the incorporation of an on-line rate adaptation mechanism as well as a static network provisioning approach and observe that these approaches can lead to a substantial reduction in energy consumption for CCN. On the other hand, an IP-based network cannot benefit from rate adaptation due to the absence of the cache capable routers.
CCN (Content Centric Networks) est une architecture réseau récemment proposée. Elle peut potentiellement réduire l'utilisation de bande passante et améliorer l'extensibilité et la sécurité du réseau par rapport à l'architecture IP existante. Dans cette thése, nous conduisons une analyse énergétique comparative des CCN et des réseaux IP dans le cas du streaming vidéo. Nous considérons deux types de consommation d'énergie: celle requise pour construire les éléments du réseau et celle requise pour le fonctionnement du réseau. Nous réalisons des simulations de CCN sur trois topologies réseaux différentes (réseau en arbre, réseau de distribution et maillage partiel) afin de vérifier la réduction du traffic obtenue avec l'introduction d'un cache aux niveau des routeurs. Nous générons deux types de demandes de traffic (Zipf et distribution uniforme) pour réaliser cette analyse. Bien que les éléments d'un réseau CCN aient une plus grande consommation d'énergie par rapport à leur équivalent des réseaux IP et qui sont dues à la présence de mémoire supplémentaire, l'exploitation de leur capacité de cache permet de réduire la consommation d'énergie totale du réseau. Contenu de mise en cache au niveau des routeurs présents sur les niveaux inférieurs du réseau (clients prés) se traduit par la réduction du trafic sur les liens qui sont à proximité du serveur (source de contenu). Nous exploitons cette caractéristique du CCN à base de réseau à l'aide d'adaptation de débit pour obtenir des avantages de l'énergie. Nous considérons à la fois l'incorporation d'un mécanisme en ligne taux d'adaptation ainsi que d'un réseau statique approche de provisionnement et d'observer que ces approches peuvent conduire à une réduction substantielle de la consommation d'énergie pour les CCN. D'autre part, un réseau basé sur IP ne peut pas bénéficier de l'adaptation du débit en raison de l'absence des routeurs capables de cache.

The underlying architecture of the Internet has been mostly the same since its beginning in the 1960s and the TCP/IP protocol stack remains ubiquitous. However the Internet is today used for much wider purposes than what was originally intended and now the most common use of the Internet is for the distribution of various forms of content. Information Centric Networking (ICN) is an alternative architecture responding to this change in usage, intended to be more prepared to handle the new requirements of the Internet not only today but also in the future. The primary concern in ICN is the secure and efficient distribution of content. Current ICN research often concerns applications on various disaster scenarios as it is believed that ICN has properties that match the requirements of such scenarios. In this thesis that research is continued by developing an especially designed information retention solution, using the existing ICN implementation of Content Centric Networking (CCN). The aim is to maximisise and prolong the availability of as much content as possible in disaster-stricken networks by preemptively replicating content across the network topology. The solution is then evaluated against a scenario set in a network topology consisting of virtual machines. The final result is that the solution performs satisfactorily and thus demonstrate the potential of ICN when applied to such scenarios.
Internets underliggande arkitektur har varit i stort sett oförändrad sedan sin begynnelse på 1960-talet, och TCP/IP protokollstacken är fortsatt universell. Dock så används Internet idag för betydligt bredare ändamål än de ursprungliga syftena, och nu används Internet främst för att distribuera olika former av innehåll. Information Centric Networking (ICN) är en alternativ arkitektur som svarar på denna förändring i använding, avsedd att vara mer förberedd att hantera de nya kraven på Internet inte bara idag men också i framtiden. Den största angelägenheten i ICN är att distribuera innehåll på ett säkert och effektivt vis. Nuvarande forskning inom ICN handlar ofta om tillämpningar på olika sorters katastrofscenarier då tron är att ICN har egenskaper som motsvarar kraven hos sådana scenarier. I den här uppsatsen fortsätts denna forskning genom att en speciellt formgiven informationsbevaringslösning utvecklas, som nyttjar den existerande ICN-implementationen Content Centric Networking (CCN). Målet är att maximera och förlänga tillgängligheten av så mycket innehåll som möjligt i katastrofdrabbade nätverk genom att i förebyggande syfte replikera innehåll genom nätverkstopologin. Lösningen evalueras sedan mot ett scenario som utspelas i en nätverkstopologi utav virtuella maskiner. Det slutgiltiga resultatet är att lösningen presterar tillfredsställande och på så vis demonstrerar potentialen hos ICN vid tillämpning på sådana scenarion.

TCP/IP protocol gradually exposes many shortcomings such as poor scalability and mobility. Content-Centric Networking is a new architecture which cares about the content itself rather than its source. Therefore, this paper proposes a novel IoV architecture which based on Content-Centric Networking and tests its transmission interference time, transmission delay, and throughout in network layer. The experimental results show that the novel architecture is superior to the current IoV in the communication performance.

L'architecture de l'Internet, basée sur IP, a été crée dans les années 70. Les nouvelles technologies et l'évolution des usages de l'Internet démontrent les limites de ce modèle. Pour remédier à ces limites, Van Jacobson et son équipe ont proposé Content- Centric Networking (CCN). CCN a pour objectif de construire un réseau orienté contenus, où l'architecture et toutes les activités de réseau sont basés sur le contenu. CCN intègre de nombreuses fonctionnalités dans les réseaux. Cette proposition a plusieurs avantages mais elle apporte également des challenges pour les technologies matérielles actuelles. La transition des adresses IP vers les noms de contenu nécessite un grand espace de mémoire. Mais les mémoires rapides d'aujourd'hui ne peuvent pas répondre à ce besoin. Dans cette thèse, je me suis concentré d'abord sur l'élément PIT (Pending Interest Table) des noeuds CCN. Je propose un système de PIT distribué, basé sur les filtres de Bloom, pour réduire les besoins de mémoire et améliorer les performances de routage. Le principe est que chaque face CCN gère sa propre table PIT au lieu d'utiliser une table centralisée. Cette conception distribuée résout le problème de récupération des informations, qui est une contrainte native des filtres de Bloom. Ainsi la vitesse de traitement et de routage sont améliorées. Par la suite, je me suis focalisé sur l'élément FIB (Forwarding Information Base). Dans la conception de CCN, la table FIB est remplie par les publications de contenus diffusées. En ce qui concerne le grand nombre de noms de contenu, cette méthode non seulement génère une taille de FIB démesurée, mais introduit également une charge de trafic réseau important. Je propose un système de forwarding dynamique, basé sur les contenus, qui contient un protocole de publications de contenus, un algorithme de remplissage de la FIB, et un élément de transmission vers l'aval. Le protocole de publication demande que chaque annonce soit envoyée seulement vers certains noeuds. L'élément de transmission en aval s'occupe de trouver les autres sources potentielles de contenu. Dans la troisième contribution, j'ai proposé une interface pour connecter le réseau CCN avec les services CDN. Le point clé de l'interconnexion de CCN avec CDN concerne la gestion de miss-hit dans les serveurs CDN. La proposition originale CCN ne permet pas une interconnexion efficace entre CDN et CCN. J'ai proposé un système, qui comprend un élément en charge du transfert des requêtes vers des serveurs CDN et un mécanisme de redirection, pour des requêtes qui ont des miss-hit, vers des serveurs originaux. Pour résumer, cette thèse contient trois contributions, qui se concentrent individuellement sur différents composants d'un noeud CCN. Chacune de ces propositions améliore les performances des noeuds CCN. Ils peuvent être combinés pour créer un noeud CCN complet, plus efficace et réaliste
The current IP based Internet architecture was designed in 70s. The development of new technologies and the evolution of Internet usages make the limitations of this design more visible, especially for the content delivery services. Facing this shortcoming, Van Jacobson and his PARC team proposed Content-Centric Network (CCN) in 2009. The CCN aims to build a content-oriented network, which means the entire networking architecture and all the networking activities are based on the content (content names in particular). The CCN proposal integrates many features such as on-path caching, security, multicast, and native mobility management. This novel proposal has many benefits but it brings also a lot of challenges for current hardware technologies. The transition from IP addresses to content names requires a large memory space to store the content names. However today's fast memory chip cannot meet this requirement. In this thesis I firstly focus on the PIT (Pending Interest Table) element in CCN routers. I propose a distributed PIT system based on the Bloom filter structure to reduce memory requirements and further improve routing performances. The principle of my proposal is that each CCN face manages its own PIT table instead of using a global table read/write lock for a centralized table. This distributed design resolves the information retrieval problem, which is a native shortcoming of Bloom filters. Thus treatment and routing speeds are improved. Thereafter I concentrate on the FIB (Forwarding Information Base) element. In the original CCN design, the FIB is filled by flooding content advertisement. With respect to the huge number of potential content names, this method not only explodes the capacity of FIB tables, but also introduces a high networking traffic. I propose a content-aware CCN forwarding system, which includes a content advertisement publish protocol, a FIB filling algorithm and a downstream forwarding element. In short, the content publish protocol requires that each advertisement is forwarded only towards certain nodes while the downstream forwarding element is a table that is in charge of discovering the other potential content sources. In the third contribution I propose an interface for interconnecting the CCN networking structure with the CDN services. The CDN service has so far been the way to address the content delivery issues of Internet. The key point of interconnecting CCN with CDN service is how to resolve the CDN repository miss-hit problem. The original CCN proposal does not enable efficient interconnection between CDN and CCN. I propose a system, which includes a CDN repository forwarding element and a CDN repository miss awareness mechanism. The former element is in charge of sending the related Interests towards the CDN repositories while the latter one aims to detect the CDN content miss and recover this lost

Content-centric networking (CCN) has emerged as a dominant paradigm for future Internet architecture design due to its efficient support for content dissemination, which currently dominates Internet use. This dissertation shows how economic and social welfare analysis can be used to inform the design of a CCN architecture that provides network stakeholders with incentives to deploy and use. Firstly, the dissertation investigates the economic incentives of different stakeholders to deploy content-centric network Internet architectures and shows that network operators will fail to deploy sufficient storage infrastructure to support CCN without payment ows from publishers. However, the level of payment required differs for different network players, which gives them different competitive advantages in providing storage infrastructure and content delivery services. Secondly, it evaluates the social welfare implications of different storage deployment scenarios in a CCN-based architecture and identifies two deployments that maximize social welfare. In the first, edge networks provide the storage infrastructure through a transaction broker. In the second, edge networks pay third-parties an amount, equivalent to the realized benefits from a storage node, to deploy storage infrastructure in the network. All other deployment scenarios lead to a deadweight loss. Thirdly, the dissertation identifies content delivery functionalities that break in a CCN-based architecture and shows how these functionalities can be successfully replicated and enhanced by a careful design of the structure of routable content, content naming and the meta-information added to content. The proposed design supports several content delivery applications and can be easily extended to other networking principals. Finally, the dissertation identifies and discusses threats in the CCN content delivery model and proposes some mechanisms to address these threats. In addition, the dissertation identifies some policy implications of the CCN content delivery model and proposes some policy interventions that may lead to desirable deployment outcomes.

The Internet was originally designed to be a next-generation phone system that could withstand a Soviet attack. Today, we ask the Internet to perform tasks that no longer resemble phone calls in the face of threats that no longer resemble Soviet bombardment. However, we have come to rely on names that can be subverted at every level of the stack or simply be allowed to rot by their original creators. It is possible for us to build networks of content that serve the content distribution needs of today while withstanding the hostile environment that all modern systems face. This dissertation presents the Cryptographically Curated File System (CCFS), which offers five properties that we feel a modern content distribution system should provide. The first property is Strong Links, which maintains that only the owner of a link can change the content to which it points. The second property, Permissionless Distribution, allows anyone to become a curator without dependence on a naming or numbering authority. Third, Independent Validation arises from the fact that the object seeking affirmation need not choose the source of trust. Connectivity, the fourth property, allows any curator to delegate and curate the right to alter links. Each curator can delegate the control of a link and that designee can do the same, leaving a chain of trust from the original curator to the one who assigned the content. Lastly, with the property of Collective Confidence, trust does not need to come from a single source, but can instead be an aggregate affirmation. Since CCFS embodies all five of these properties, it can serve as the foundational technology for a more robust Web. CCFS can serve as the base of a web that performs the tasks of today’s Web, but also may outperform it. In the third chapter, we present a number of scenarios that demonstrate the capacity and potential of CCFS. The system can be used as a publication platform that has been re-optimized within the constraints of the modern Internet, but not the constraints of decades past. The curated links can still be organized into a hierarchical namespace (e.g., a Domain Naming System (DNS)) and de jure verifications (e.g., a Certificate Authority (CA) system), but also support social, professional, and reputational graphs. This data can be distributed, versioned, and archived more efficiently. Although communication systems were not designed for such a content-centric system, the combination of broadcasts and point-to-point communications are perfectly suited for scaling the distribution, while allowing communities to share the burdens of hosting and maintenance. CCFS even supports the privacy of friend-to-friend networks without sacrificing the ability to interoperate with the wider world. Finally, CCFS does all of this without damaging the ability to operate search engines or alert systems, providing a discovery mechanism, which is vital to a usable, useful web. To demonstrate the viability of this model, we built a research prototype. The results of these tests demonstrate that while the CCFS prototype is not ready to be used as a drop-in replacement for all file system use cases, the system is feasible. CCFS is fast enough to be usable and can be used to publish, version, archive, and search data. Even in this crude form, CCFS already demonstrates advantages over previous state-of-the-art systems. When the Internet was designed, there were relatively fewer computers that were far weaker than the computers we have now. They were largely connected to each other over reliable connections. When the Internet was first created, computing was expensive and propagation delay was negligible. Since then, the propagation delay has not improved on a Moore’s Law Curve. Now, latency has come to dominate all other costs of retrieving content; specifically, the propagation time has come to dominate the latency. In order to improve the latency, we are paying more for storage, processing, and bandwidth. The only way to improve propagation delay is to move the content closer to the destination. In order to have the content close to the demand, we store multiple copies and search multiple locations, thus trading off storage, bandwidth, and processing for lower propagation delay. The computing world should re-evaluate these trade-offs because the situation has changed. We need an Internet that is designed for the technologies used today, rather than the tools of the 20th century. CCFS, which regards the trade-off for lower propagation delay, will be better suited for 21st-century technologies. Although CCFS is not preferable in all situations, it can still offer tremendous value. Better robustness, performance, and democracy make CCFS a contribution to the field. Robustness comes from the cryptographic assurances provided by the five properties of CCFS. Performance comes from the locality of content. Democracy arises from the lack of a centralized authority that may grant the right of Free Speech only to those who espouse rhetoric compatible with their ideals. Combined, this model for a cryptographically secure, content-centric system provides a novel contribution to the state of communications technology and information security.

Dans les dernières années, l'utilisation d'Internet a sensiblement changé en passant d'un modèle de communication centré sur les machines á un centré sur les contenus. La plus part de services utilisés par les clients d'Internet aujourd'hui sont déjà centré sur les contenus même et pas sur leurs emplacement. Dans ce contexte, beaucoup de projets de recherche proposent un changement de l'architecture de l'Internet, en mettent des contenu identifié par leur nom au centre du réseau. Ce group de proposition est identifiés sous le nom de Information Centric Networking (ICN). Cette thèse se focalise sur la proposition Content-Centric Network (CCN). Dans une premier temps, nous analysons les performance du modèle de communication CCN en se concentrent sur le partage de la bande passante et de la mémoire et en proposant des formules pour la caractérisation du temps de transfert. Deuxièmement, nous proposons un protocole de contrôle de congestion et des mécanismes de forwarding pour CCN. En particulier on présent un premier mécanisme de contrôle de congestion, Interest Control Protocol (ICP), qui utilise une fenêtre contrôlé avec le mécanisme Additive Increase Multiplicative Decrease au récepteur. En complément avec ça, nous présentons un mécanisme distribué (hop-by-hop) pour obtenir une détection/réaction à la congestion plus rapide. Nous proposons aussi une modification d'ICP en implémentant le mécanisme Remote Adaptive Active Queue Management pour exploiter efficacement le multi-chemin. En fin, nous présentons un mécanisme de forwarding distribué qui base ses décisions sur des mesure de qualité d'interface par chaque préfixe disponible dans les tableaux de routage.

The market of IOT devices continues to grow at a rapid speed as well as constrained wireless sensor networks. Today, the main network paradigm is host centric where a users have to specify which host they want to receive their data from. Information-centric networking is a new paradigm for the future internet, which is based on named data instead of named hosts. With ICN, a user needs to send a request for a perticular data in order to retrieve it. When sent, any participant in the network, router or server, containing the data will respond to the request. In order to achieve low latency between data creation and its consumption, as well as being able to follow data which is sequentially produced at a fixed rate, an algortihm was developed. This algortihm calculates and determines when to send the next interest message towards the sensor. It uses a ‘one time subscription’ approach to send its interest message in advance of the creation of the data, thereby enabling a low latency from data creation to consumption. The result of this algorithm shows that a consumer can retrieve the data with minimum latency from its creation by the sensor over an extended period of time, without using a publish/subscribe system such as MQTT or similar which pushes their data towards their consumers. The performance evaluation carried out which analysed the Content Centric Network application on the sensor shows that the application has little impact on the overall round trip time in the network. Based on the results, this thesis concluded that the ICN paradigm, together with a ’one-time subscription’ model, can be a suitable option for communication within the IoT domain where consumers ask for sequentially produced data.

In the last years, some new paradigms are emerging in the networking area as inspiring models for the definition of future communications networks. A key example is certainly the Content Centric Networking (CCN) protocol suite, namely a novel network architecture that aims to supersede the current TCP/IP stack in favor of a name based routing algorithm, also introducing in-network caching capabilities. On the other hand, much interest has been placed on Software Defined Networking (SDN), namely the set of protocols and architectures designed to make network devices more dynamic and programmable. Given this complex arena, the thesis focuses on the analysis of these innovative network protocols, with the aim of exploring possible design flaws and hence guaranteeing their proper operation when actually deployed in the network. Particular emphasis is given to the security of these protocols, for its essential role in every wide scale application. Some work has been done in this direction, but all these solutions are far to be considered fully investigated. In the CCN case, a closer investigation on problems related to possible DDoS attacks due to the stateful nature of the protocol, is presented along with a full-fledged proposal to support scalable PUSH application on top of CCN. Concerning SDN, instead, we present a tool for the verification of network policies in complex graphs containing dynamic network functions. In order to obtain significant results, we leverage different tools and methodologies: on the one hand, we assess simulation software as very useful tools for representing the most common use cases for the various technologies. On the other hand, we exploit more sophisticated formal methods to ensure a higher level of confidence for the obtained results.

Les Réseaux Orientés Contenus (Information Centric Networking (ICN)) représentent un nouveau paradigme qui se développe de plus en plus dans le monde de l’Internet. Ils mettent en avant de nouvelles approches centrées sur le contenu pour concevoir une nouvelle architecture pour le réseau Internet du futur dont l’usage bascule aujourd’hui d’une communication orientée machines (hosts) vers une distribution et une récupération de contenus à large échelle.Dans ce cadre, plusieurs architectures de type ICN ont été proposées par la communauté scientifique dans le cadre de plusieurs projets internationaux : DONA, PURSUIT, SAIL, COMET, CONVERGENCE, Named Data Networking (NDN), etc.Nos travaux de thèse se sont focalisés sur la problématique du routage dans les réseaux de ce type, au travers d’une architecture de type NDN qui représente aujourd’hui une des architectures ICN les plus évoluées.En particulier, nous nous sommes intéressés à concevoir et à mettre en œuvre des solutions de routage qui intègrent les métriques de qualité de service (QdS) dans les architectures NDN au regard de usages courants dans le réseau Internet. Celui-ci est en effet caractérisé par une hétérogénéité des liaisons et des conditions de trafic hautement dynamiques.Dans ce type d’architectures, la diffusion des paquets de données est organisée en deux plans : le plande routage et le plan d’acheminement. Ce dernier est responsable de l’acheminement des paquets sur l’ensemble des chemins disponibles au moyen d’une stratégie identifiée en amont. Le plan du routage est quant à lui utilisé uniquement pour soutenir le plan d’acheminement. De fait, les solutions que nous proposons consistent en de nouvelles stratégies d’acheminement avec QdS que nous qualifions d’adaptatives. Ces stratégies sont capables de transmettre les paquets sur de multiples chemins tout en considérant les paramètres de QdS liés à l’état du réseau et collectés en temps réel.La première approche proposée est conçue sur la base d’une méthode d’apprentissage inductif,du type Q-learning en ligne, et est utilisée pour estimer les informations collectées sur l’état dynamique du réseau.La deuxième contribution consiste dans une stratégie d’acheminement adaptatif conçue pour les architectures NDN et prenant en compte les métriques liées à la QdS. Elle est basée sur les similarités entre le processus d’acheminement des paquets dans les architectures NDN et le comportement des fourmis lors de la recherche du plus court chemin entre leur nid et les sources de nourriture. Les techniques utilisées pour concevoir cette stratégie sont inspirées des approches d’optimisation utilisées dans les algorithmes de type « colonies de fourmis ».Enfin, dans la dernière partie de la thèse, nous généralisons l’approche décrite ci-dessus pour l’étendre à la prise en compte simultanée de plusieurs paramètres de QdS. Sur la base de ces mêmes principes, cette approche a ensuite été étendue à la résolution des problèmes liés à la congestion.Les résultats obtenus montrent l’efficacité des solutions proposées dans une architecture NDN et permettent ainsi de considérer les paramètres de QdS dans les mécanismes d’acheminement des paquets ouvrant la voie à diverses applications orientées contenus sur ce type d’architecture
The Information Centric Networking (ICN) represents a new paradigm that is increasingly developed within the Internet world. It brings forward new content-centric based approaches, in order to design a new architecture for the future Internet, whose usage today shifts from a machine oriented communication (hosts) to a large-scale content distribution and retrieval.In this context, several ICN architectures have been proposed by the scientific community, within several international projects: DONA, PURSUIT, SAIL, COMET, CONVERGENCE, Named Data Networking (NDN), etc.Our thesis work has focused on the problems of routing in such networks, through a NDN architecture, which represents one of the most advanced ICN architectures nowadays.In particular, we were interested in designing and implementing routing solutions that integrate quality-of-service metrics (QoS) in the NDN architecture in terms of current Internet usage. This latter is indeed characterized by a heterogeneity of connections and highly dynamic traffic conditions.In this type of architecture, data packets broadcast is organized in two levels: the routing planand the forwarding plane. The latter is responsible for routing packets on all available paths through an identified upstream strategy. The routing plan is meanwhile used only to support the forwarding plane. In fact, our solutions consist of new QoS routing strategies which we describe as adaptive. These strategies can transmit packets over multiple paths while taking into account the QoS parameters related to the state of the network and collected in real time.The first proposed approach is designed on the basis of a on-line Q-learn type inductive learning method, and is used to estimate the information collected on the dynamic state of the network.The second contribution is an adaptive routing strategy designed for NDN architectures which considers the metrics related to QoS. It is based on the similarities between the packet forwarding process in the NDN architecture and the behavior of ants when finding the shortest path between their nest and food sources. The techniques used to design this strategy are based on optimization approaches used "ant colonies" algorithms.Finally, in the last part of the thesis, we generalize the approach described above to extend it to the simultaneous consideration of several QoS parameters. Based on these principles, this approach was later extended to solving problems related to congestion.The results show the effectiveness of the proposed solutions in an NDN architecture and thus allow to consider QoS parameters in packet delivery mechanisms paving the way for various content-oriented applications on this architecture

Dans les dernières années, l’utilisation d’Internet a sensiblement changé en passant d’un modèle de communication centré sur les machines á un centré sur les contenus. La plus part de services utilisés par les clients d’Internet aujourd’hui sont déjà centré sur les contenus même et pas sur leurs emplacement. Dans ce contexte, beaucoup de projets de recherche proposent un changement de l’architecture de l’Internet, en mettent des contenu identifié par leur nom au centre du réseau. Ce group de proposition est identifiés sous le nom de Information Centric Networking (ICN). Cette thèse se focalise sur la proposition Content-Centric Network (CCN). Dans une premier temps, nous analysons les performance du modèle de communication CCN en se concentrent sur le partage de la bande passante et de la mémoire et en proposant des formules pour la caractérisation du temps de transfert. Deuxièmement, nous proposons un protocole de contrôle de congestion et des mécanismes de forwarding pour CCN. En particulier on présent un premier mécanisme de contrôle de congestion, Interest Control Protocol (ICP), qui utilise une fenêtre contrôlé avec le mécanisme Additive Increase Multiplicative Decrease au récepteur. En complément avec ça, nous présentons un mécanisme distribué (hop-by-hop) pour obtenir une détection/réaction à la congestion plus rapide. Nous proposons aussi une modification d'ICP en implémentant le mécanisme Remote Adaptive Active Queue Management pour exploiter efficacement le multi-chemin. En fin, nous présentons un mécanisme de forwarding distribué qui base ses décisions sur des mesure de qualité d’interface par chaque préfixe disponible dans les tableaux de routage
The advent of the World Wide Web has radically changed Internet usage from host-to-host to service access and data retrieval. The majority of services used by Internet’s clients are content-centric (e.g. web). However, the original Internet revolves around host-to-host communication for which it was conceived. Even if Internet has been able to address the challenges offered by new applications, there is an evident mismatch between the architecture and its current usage. Many projects in national research agencies propose to redesign the Internet architecture around named data. Such research efforts are identified under the name of Information Centric Networking. This thesis focuses on the Content-Centric Networking (CCN) proposition. We first analyze the CCN communication model with particular focus on the bandwidth and storage sharing performance, We compute closed formulas for data delivery time, that we use in the second part of the thesis as guideline for network protocol design. Second, we propose some CCN congestion control and forwarding mechanisms. We present a first window based receiver driven flow control protocol, Interest Control Protocol (ICP). We also introduce a hop-by-hop congestion control mechanism to obtain early congestion detection and reaction. We then extend the original ICP congestion control protocol implementing a Remote Adaptive Active Queue Management mechanism in order to efficiently exploit heterogeneous (joint/disjoint) network paths. Finally, we introduce a distributed forwarding mechanism that bases its decisions on per prefix and per interface quality measurement without impacting the system scalability

Au cours des dernières années, les fournisseurs de contenu ont connu une forte augmentation des demandes de contenus vidéo et de services riches en média. Compte tenu des limites de la mise à l'échelle du réseau et au-delà des réseaux de diffusion de contenu, les fournisseurs de services Internet développent leurs propres systèmes de mise en cache afin d'améliorer la performance du réseau. Ces facteurs expliquent l'enthousiasme à l'égard du concept de réseau centré sur le contenu et de sa fonction de mise en cache en réseau. La quantification analytique de la performance de la mise en cache n'est toutefois pas suffisamment explorée dans la littérature. De plus, la mise en place d'un système de caching efficace au sein d'une infrastructure réseau est très complexe et demeure une problématique ouverte. Pour traiter ces questions, nous présentons d'abord dans cette thèse un modèle générique et précis de cache nommé MACS (Markov chain-based Approximation of Caching Systems) qui peut être adapté très facilement pour représenter différents schémas de mise en cache et qui peut être utilisé pour calculer différentes mesures de performance des réseaux multi-cache. Nous avons ensuite abordé le problème de l'allocation des ressources de cache dans les réseaux avec capacité de caching. Moyennant notre outil analytique MACS, nous présentons une approche permettant de résoudre le compromis entre différentes mesures de performance en utilisant l'optimisation multi-objectif et nous proposons une adaptation de la métaheuristique GRASP pour résoudre le problème d'optimisation
In the last few years, Content Providers (CPs) have experienced a high increase in requests for video contents and rich media services. In view of the network scaling limitations and beyond Content Delivery Networks (CDNs), Internet Service Providers (ISPs) are developing their own caching systems in order to improve the network performance. These factors explain the enthusiasm around the Content-Centric Networking (CCN) concept and its in-network caching feature. The analytical quantification of caching performance is, however, not sufficiently explored in the literature. Moreover, setting up an efficient caching system within a network infrastructure is very complex and remains an open problem. To address these issues, we provide first in this thesis a fairly generic and accurate model of caching nodes named MACS (Markov chain-based Approximation of Caching Systems) that can be adapted very easily to represent different caching schemes and which can be used to compute different performance metrics of multi-cache networks. We tackled after that the problem of cache resources allocation in cache-enabled networks. By means of our analytical tool MACS, we present an approach that solves the trade-off between different performance metrics using multi-objective optimization and we propose an adaptation of the metaheuristic GRASP to solve the optimization problem

Un content delivery network (CDN), ou réseau de diffusion de contenu, Sont considérés comme la solution potentielle pour délivrer le volume de contenu croissant. Bien que les solutions CDN soient progressivement intégrées à l'infrastructure réseau, elles montrent toujours des limites technologiques pour faire face au nombre croissant d'applications exigeantes et gourmande en bande passante. Dans cette thèse, la principale cible de nos contributions est le routage des requêtes, qui est un mécanisme de livraison de contenu qui a un impact clé sur l'échelle et la performance du CDN, ainsi que sur la qualité de l'expérience perçue par l'utilisateur.Nous présentons tout d'abord un schéma flexible et un algorithme d'optimisation, basé sur la théorie de Lyapunov, pour le routage des requêtes dans les CDN. Notre approche en ligne fournit une qualité de service stable aux clients, tout en améliorant les délais de livraison de contenu. Elle réduit également les coûts de transport des données pour les opérateurs et surpasse les techniques existantes en termes de gestion du trafic de pointe.Deuxièmement, pour surmonter les limites du mécanisme de redirection utilisé dans les solutions de routage de demandes, nous introduisons une nouvelle approche de diffusion de contenu intégrant des principes de réseau centré sur l'information ou Information-centric networking (ICN) sans nécessiter de changement dans le réseau sous-jacent. Cette solution améliore les performances de diffusion de contenu et permet la mise en œuvre de stratégies de routage de demandes rentables
Today, many devices are capable to capture full HD videos and use their network connections to access the Internet. The popularization of these devices and continuous efforts to increase network quality has brought a proper environment for the rise of live streaming. Associated with the large scale of Users Generated Content (UGC), live streaming presents new challenges. Content Delivery Networks (CDN)are considered as the potential solution to deliver this rising content volume. Although CDN solutions are progressively integrated with the network infrastructure, they still show technological limitations in dealing with the increasing amount of bandwidth-hungry and demanding applications. In this thesis, the main target of our contributions is request routing, which is a content delivery mechanism that has a key impact on scale and performance of the CDN, as well as on the perceived Quality of Experience (QoE). First, we present a flexible scheme and an optimization algorithm, based on Lyapunov theory, for request routing in CDNs. Our online approach provides a stable quality of service to clients, while improving content delivery delays. It also reduces data transport costs for operators and outperforms existing techniques in terms of peak traffic management.Second, to overcome the limitations of the redirection mechanism used in current request routing solutions, we introduce a new approach to content delivery incorporating Information-Centric Networking (ICN) principles without requiring any change in the underlying network. This solution improves content delivery performance and enables the implementation of cost efficient request routing strategies

Un content delivery network (CDN), ou réseau de diffusion de contenu, Sont considérés comme la solution potentielle pour délivrer le volume de contenu croissant. Bien que les solutions CDN soient progressivement intégrées à l'infrastructure réseau, elles montrent toujours des limites technologiques pour faire face au nombre croissant d'applications exigeantes et gourmande en bande passante. Dans cette thèse, la principale cible de nos contributions est le routage des requêtes, qui est un mécanisme de livraison de contenu qui a un impact clé sur l'échelle et la performance du CDN, ainsi que sur la qualité de l'expérience perçue par l'utilisateur.Nous présentons tout d'abord un schéma flexible et un algorithme d'optimisation, basé sur la théorie de Lyapunov, pour le routage des requêtes dans les CDN. Notre approche en ligne fournit une qualité de service stable aux clients, tout en améliorant les délais de livraison de contenu. Elle réduit également les coûts de transport des données pour les opérateurs et surpasse les techniques existantes en termes de gestion du trafic de pointe.Deuxièmement, pour surmonter les limites du mécanisme de redirection utilisé dans les solutions de routage de demandes, nous introduisons une nouvelle approche de diffusion de contenu intégrant des principes de réseau centré sur l'information ou Information-centric networking (ICN) sans nécessiter de changement dans le réseau sous-jacent. Cette solution améliore les performances de diffusion de contenu et permet la mise en œuvre de stratégies de routage de demandes rentables
Today, many devices are capable to capture full HD videos and use their network connections to access the Internet. The popularization of these devices and continuous efforts to increase network quality has brought a proper environment for the rise of live streaming. Associated with the large scale of Users Generated Content (UGC), live streaming presents new challenges. Content Delivery Networks (CDN)are considered as the potential solution to deliver this rising content volume. Although CDN solutions are progressively integrated with the network infrastructure, they still show technological limitations in dealing with the increasing amount of bandwidth-hungry and demanding applications. In this thesis, the main target of our contributions is request routing, which is a content delivery mechanism that has a key impact on scale and performance of the CDN, as well as on the perceived Quality of Experience (QoE). First, we present a flexible scheme and an optimization algorithm, based on Lyapunov theory, for request routing in CDNs. Our online approach provides a stable quality of service to clients, while improving content delivery delays. It also reduces data transport costs for operators and outperforms existing techniques in terms of peak traffic management.Second, to overcome the limitations of the redirection mechanism used in current request routing solutions, we introduce a new approach to content delivery incorporating Information-Centric Networking (ICN) principles without requiring any change in the underlying network. This solution improves content delivery performance and enables the implementation of cost efficient request routing strategies

Cette thèse apporte des contributions à la modélisation, compréhension ainsi qu'à la communication efficace d'information dans les réseaux dynamiques peuplant la périphérie de l'Internet. Par réseaux dynamiques, nous signifions les réseaux pouvant être modélisés par des graphes dynamiques dans lesquels noeuds et liens évoluent temporellement. Dans la première partie de la thèse, nous proposons un nouveau modèle de mobilité - STEPS - qui permet de capturer un large spectre de comportement de mobilité humains. STEPS mets en oeuvre deux principes fondamentaux de la mobilité humaine : l'attachement préférentiel à une zone de prédilection et l'attraction vers une zone de prédilection. Nous proposons une modélisation markovienne de ce modèle de mobilité. Nous montrons que ce simple modèle paramétrique est capable de capturer les caractéristiques statistiques saillantes de la mobilité humaine comme la distribution des temps d'inter-contacts et de contacts. Dans la deuxième partie, en utilisant STEPS, nous analysons les propriétés comportementales et structurelles fondamentales des réseaux opportunistes. Nous redéfinissons dans le contexte des réseaux dynamiques la notion de structure petit monde et montrons comment une telle structure peut émerger. En particulier, nous montrons que les noeuds fortement dynamiques peuvent jouer le rôle de ponts entre les composants déconnectés, aident à réduire significativement la longueur du chemin caractéristique du réseau et contribuent à l'émergence du phénomène petit-monde dans les réseaux dynamiques. Nous proposons une façon de modéliser ce phénomène sous STEPS. À partir d'un réseau dynamique régulier dans lequel les noeuds limitent leur mobilité à leurs zones préférentielles respectives. Nous recablons ce réseau en injectant progressivement des noeuds nomades se déplaçant entre plusieurs zones. Nous montrons que le pourcentage de tels nœuds nomades est de 10%, le réseau possède une structure petit monde avec un fort taux de clusterisation et un faible longueur du chemin caractéristique. La troisième contribution de cette thèse porte sur l'étude de l'impact du désordre et de l'irrégularité des contacts sur la capacité de communication d'un réseau dynamique. Nous analysons le degré de désordre de réseaux opportunistes réels et montrons que si exploité correctement, celui-ci peut améliorer significativement les performances du routage. Nous introduisons ensuite un modèle permettant de capturer le niveau de désordre d'un réseau dynamique. Nous proposons deux algorithmes simples et efficaces qui exploitent la structure temporelle d'un réseau dynamique pour délivrer les messages avec un bon compromis entre l'usage des ressources et les performances. Les résultats de simulations et analytiques montrent que ce type d'algorithme est plus performant que les approches classiques. Nous mettons également en évidence aussi la structure de réseau pour laquelle ce type d'algorithme atteint ses performances optimum. Basé sur ce résultat théorique nous proposons un nouveau protocole de routage efficace pour les réseaux opportunistes centré sur le contenu. Dans ce protocole, les noeuds maintiennent, via leurs contacts opportunistes, une fonction d'utilité qui résume leur proximité spatio-temporelle par rapport aux autres noeuds. En conséquence, router dans un tel contexte se résume à suivre le gradient de plus grande pente conduisant vers le noeud destination. Cette propriété induit un algorithme de routage simple et efficace qui peut être utilisé aussi bien dans un contexte d'adressage IP que de réseau centré sur les contenus. Les résultats de simulation montrent que ce protocole superforme les protocoles de routage classiques déjà définis pour les réseaux opportunistes. La dernière contribution de cette thèse consiste à mettre en évidence une application potentielle des réseaux dynamiques dans le contexte du " mobile cloud computing ". En utilisant les techniques d'optimisation particulaires, nous montrons que la mobilité peut augmenter considérablement la capacité de calcul des réseaux dynamiques. De plus, nous montrons que la structure dynamique du réseau a un fort impact sur sa capacité de calcul.

By suggesting radical changes to the current Internet, approaches to clean-slate architectures run the risk of introducing new opportunities for attacks. These attacks can range from new forms of denial-of-service to attacks against other users’ privacy. In this thesis, we analyse the architecture proposed by Content-Centric Networking from a security perspective. One security-critical feature of Content-Centric Networking is the introduction of general-purpose caches that are shared by a small number of users. We show how attackers can leverage these caches to monitor what content its users are retrieving. More generally, we argue that there is a tradeoff between network efficiency and user privacy. Countermeasures against cache-based privacy attacks need to carefully explore this tradeoff.

Content Centric Networking (CCN) is a novel networking architecture in which communication is resolved based on names, or descriptions of the data transferred instead of addresses of the end-hosts. While CCN demonstrates many promising potentials, its current implementation suffers from severe performance limitations. In this thesis we study the performance and analyze the bottleneck of the existing CCN prototype. Based on the analysis, a variety of design alternatives are proposed for realizing high performance content centric networking over virtual infrastructure. Preliminary implementations for two of the approaches are developed and evaluated on Smart Applications on Virtual Infrastructure (SAVI) testbed. The evaluation results demonstrate that our design is capable of providing scalable content centric routing solution beyond 1Gbps throughput under realistic traffic load.

Dissertação de Mestrado em Engenharia Informática apresentada à Faculdade de Ciências e Tecnologia da Universidade de Coimbra.
Information-Centric Networking (ICN) is a new networking concept devised to cope with the challenges faced by the current design of Internet communications, such as the rising number of users and the mobility of the devices. Although this concept already has some features that are relevant for current Internet usage, such as in-network caching capabilities and content replication, there are still some relevant improvements to be developed. One of the key aspects of ICN is the ability to deal with node mobility, since there are no persistent connections, making it stand out from the current Internet design. However, although ICN supports mobility, there are still no optimizations to better serve users on the move. By tracking the contents’ popularity at the users’ sources, it is possible to pre-cache related contents to the ones accessed by the users at their destination. This pre-caching allows to better serve those users when they arrive, providing reduced delays while obtaining the pre-cached contents. Content-Centric Networking (CCN) is one of the existent ICN architectures and here we propose an improvement to CCN mobility capabilities: smart relocation of contents, based on users’ movement. In this work, we design, implement and validate smart content relocation mechanisms able to integrate with the core system of CCNx to anonymously monitor data requests and relocate relevant data according to the users’ upcoming destination prior to their arrival. This will allow an improvement on the users’ service experience, namely regarding delay, when using CCN with content relocation.
Information-Centric Networking (ICN) é um novo conceito de redes criado com o objectivo de ultrapassar alguns dos obstáculos encontrados pela actual forma de comunicação da Internet, tais como o crescente número de utilizadores e a mobilidade dos dispositivos. A possibilidade de fazer caching por toda a rede e de replicar conteúdos são duas das características base deste novo conceito, que tem ainda muitos aspectos onde pode ser melhorado. No ICN não existem ligações permanentes entre dois nós, ao contrário do actual conceito da Internet, o que faz com que este consiga lidar bem com a mobilidade dos nós, um dos principais aspectos que se salienta comparando à actualidade. No entanto não foram ainda desenvolvidas nenhum tipo de optimizações para melhor responder aos utilizadores que estão em movimento. Através da monitorização dos conteúdos populares entre os utilizadores, é possível fazer um pre-caching quando estes se movem, para assim melhor a sua experiência quando chegam ao destino, nomeadamente apresentando atrasos menores. Content-Centric Networking (CCN) é uma das várias arquitecturas de ICN existentes à qual é proposta uma melhoria: relocalização inteligente de conteúdos com base no deslocamento dos utilizadores. Neste trabalho desenhamos, implementamos e validamos esta proposta e a sua integração com o sistema base do CCNx através da monitorização anónima dos conteúdos e da migração dos conteúdos relevantes para o destino dos utilizadores. Esta migração permitirá uma melhoria na experiência dos utilizadores, nomeadamente em termos de atraso quando usam CCN com a relocalização dos conteúdos.

碩士
國立交通大學
網路工程研究所
102
People have been used to obtain many kind of information from Internet, such like video, music, data. However, the explosion of Internet user and multimedia data caused many problems in current network architecture, such as insufficiency IP addresses for the increasing number of mobile devices, high bandwidth consumption for multimedia services like Youtube, heavy server loading for hundred thousand of multimedia connections, etc. For these reasons, the Content-Centric Networking (CCN) is proposed to provide a new networking paradigm. It uses content name to replace the IP address and allows each CCN router to cache content. The user no longer cares where but what the content is. In CCN, a request with the content name will hit the cache as it passes through the router on the way to a data server. As a result, data can be coming from a nearby router instead of the server. Therefore, both bandwidth consumption and server loading can be decreased. However, how to realize CCN in current network architecture becomes an important issue. We propose to use Software-defined networking (SDN) to realize content-centric network named Open-CCN. In order to coexist with IP network and allow current IP devices to access Open-CCN seamlessly, an IP-Name translation proxy server and tunneling are introduced. In addition, we proposed a multiple sources transport protocol in order to improve data transmission rate. Finally, we use the commercial network appliances to build a small network to demonstrate the function and the performance of each network component in our Open-CCN network.

碩士
世新大學
資訊管理學研究所(含碩專班)
102
With the popularity of content production and dissemination applications such as sharing videos on YouTube and social networking services, Internet has been rapidly growing and becoming one of the leading players in energy consumption. Recently, Content-centric Net-working (CCN), whose aim is to redesign the Internet architecture with the named-data as the primary element in the novel networking paradigm, has attracted wide research interests. In CCN, content items are uniquely identified by hierarchical names and requested by receivers via Interest packets. The CCN enabled routers (CCNR) will handle and forward the Interest packets toward the original content servers and send the data packets back to the receivers. The data packets can be cached by any CCNR so as to serve future redundant interest packets. In terms of energy efficiency, CCN requires less transport energy but additional energy to provide a caching capability at every CCNR. In this paper, we study on the issues of energy efficient caching for CCN architecture. We first analyze the threshold level from which caching content starts to be beneficial for a CCNR and develop a simple strategy to reduce redundant data. We then propose a cache replacement policy based on the content request rate and the degree of branching which is defined as the number of different neighboring nodes from which the Interest packets are received. Furthermore, we demonstrate the effectiveness of our proposed caching scheme by simulations.

Over the past few years Information-Centric Networking, a networking architecture in which host-to-content communication protocols are introduced, has been gaining much attention. A central component of such an architecture is a large-scale interconnected caching system. To date, the modeling of these cache networks, as well as understanding of how they should be managed, are both in their infancy. This dissertation sets out to consider both of these challenges. We consider approximate and bounding analysis of cache network performance, the convergence of such systems to steady-state, and the manner in which content should be searched for in a cache network. Taken as a whole, the work presented here constitutes an array of fundamental tools for addressing the challenges posed by this new and exciting field.

Tese de doutoramento em cotutela, na área de Ciências e Tecnologias da Informação, apresentada à Faculdade de Ciências e Tecnologia da Universidade de Coimbra e à University of Bern.
With the recent advances in mobile technology, such as the boom in the usage of smartphones and mobile networks, content demand of mobile users has increased significantly. This exponential increase exposed several limitations on the current mechanisms for content delivery. Namely, the current paradigm for requesting content focuses on resources and not on content as it would be ideal to improve content delivery. Despite the existing efforts to overcome this limitation that greatly affects overall performance and efficiency, there are still open challenges that need to be addressed. The first challenge is how to explore new technologies together with a new content request paradigm, aiming at having deeper integration with existing networks and availability of compute, storage and network resources whenever and wherever they are necessary to handle different amounts of user loads. The second challenge is dealing with the integration of content delivery mechanisms with mobile networks and all its particularities, such as constrained architectures and demanding processing requirements. The third challenge is the usage of multiple radio technologies in a transparent and coordinated manner to improve overall efficiency and performance of mobile networks. The fourth challenge is the extension of content caching to the edge of mobile networks with efficient usage of storage resources and reduced latency for content delivery. The fifth and last challenge is the proper distribution of content among edge caches ensuring adaptability to the mobility of users. The key contributions of this thesis aim at addressing those challenges, by providing an integrated architecture with a set of strategies, mechanisms and algorithms that tackle the identified problems in detail and span across multiple knowledge domains. A first contribution concerns a cloud-based system for content delivery, which is easily deployable in new locations, integrates with other services and adapts itself to different user loads. Later on, the integration of this system with mobile networks is depicted to bring the enhancements of that system directly to content delivery in mobile networks, and mechanisms to ensure that it is feasible and follows current standards and specifications are described. Afterwards, and considering that multiple network technologies can be used simultaneously, strategies are proposed to efficiently handle load balancing and offloading of content delivery between different radio technologies in mobile networks, ensuring complete transparency for end users and efficient usage of available resources. Next, and because the previous contributions make caching at the edge of mobile networks a reality, caching strategies for the edge of mobile networks are highlighted, focusing on maximizing performance in terms of latency reduction while optimizing storage usage. Finally, content distribution strategies for edge caches based on users' movement and their interests are presented. These aim at improving edge caching by trying to guarantee that content is cached where it yields the greatest benefits for nearby users. Results gathered from the evaluation of the contributions of this thesis demonstrate that they bring major benefits for content delivery and that performance is greatly enhanced. These improvements are very important from multiple perspectives, as all the involved stakeholders, from mobile users to content providers and mobile operators, may benefit at different levels such as quality of experience, satisfaction and costs.
Com os recentes avanços na tecnologia móvel, tais como o aumento estrondoso da utilização de smartphones e redes móveis, a procura de conteúdos por parte de utilizadores móveis tem aumentado significativamente. Este aumento exponencial expôs várias limitações nos mecanismos actuais para a entrega de conteúdos. Nomeadamente, o actual paradigma para solicitar conteúdos foca-se em recursos e não nos conteúdos como seria ideal para melhorar a entrega de conteúdos. Apesar dos esforços já existentes para ultrapassar esta limitação que afecta de forma substancial e genérica a performance e eficiência, ainda existem desafios em aberto para serem endereçados. O primeiro desafio é como explorar novas tecnologias em conjunto com um novo paradigma para pedido de conteúdos, com o objectivo de ter maior integração com as redes existentes e a disponibilidade de recursos de computação, armazenamento e rede quando e onde forem necessários, para assim acomodar diferentes quantidades de carga de utilizadores. O segundo desafio prende-se com a integração de mecanismos para entrega de conteúdos nas redes móveis e todas as particularidades que isso acarreta, nomeadamente arquitecturas limitadas e requisitos de processamento exigentes. O terceiro desafio é a utilização de múltiplas tecnologias de rádio de forma transparente e coordenada para aumentar de forma global a eficiência e performance das redes móveis. O quarto desafio é a extensão de caches de conteúdos até à orla das redes móveis com vista a uma utilização eficiente de recursos de armazenamento e latências reduzidas na entrega de conteúdos. O quinto e último desafio é a distribuição adequada de conteúdos entre caches na orla das redes móveis, assegurando adaptabilidade à mobilidade dos utilizadores. As contribuições chave desta tese têm como objectivo endereçar os desafios referidos anteriormente, providenciando uma arquitectura integrada com um conjunto de estratégias, mecanismos e algoritmos que tratam dos problemas identificados em detalhe e abrangem múltiplos domínios do conhecimento. Uma primeira contribuição diz respeito a um sistema baseado na nuvem para entrega de conteúdos, o qual é facilmente implementável em novas localizações, integra com outros serviços e adapta-se a si próprio a diferentes cargas de utilizadores. De seguida, é apresentada a integração deste sistema com redes móveis e são descritos mecanismos para garantir a sua praticabilidade e adequação às normas e padrões existentes, para assim trazer as suas melhorias directamente à entrega de conteúdos em redes móveis. Depois, e considerando que múltiplas tecnologias de rede podem ser utilizadas em simultâneo, são apresentadas estratégias para efectuar balanceamento e transferência de carga entre múltiplas tecnologias de rádio em redes móveis, assegurando total transparência para os utilizadores finais e uma utilização eficiente dos recursos existentes. Mais tarde, e porque as contribuições anteriores tornam a existência de caches na orla das redes móveis uma realidade, estratégias para caching na orla das redes móveis são realçadas, focando-se em maximizar a performance em termos de redução de latência e na optimização da utilização de recursos de armazenamento. Finalmente, estratégias para a distribuição de conteúdos em caches na orla das redes móveis baseadas em movimento e interesses dos utilizadores são apresentadas. Estas visam a melhoria das caches na orla das redes móveis ao tentar garantir que os conteúdos são colocados em caches onde irão trazer os maiores benefícios possíveis para utilizadores na imediação. Os resultados obtidos da avaliação das contribuições desta tese demonstram que as mesmas trazem benefícios relevantes para a entrega dos conteúdos juntamente com um aumento significativo da performance. Estas melhorias são muito importantes de múltiplas perspectivas, dado que todas as partes interessadas, desde utilizadores móveis até produtores de conteúdos e operadores móveis, podem beneficiar a diferentes níveis tais como qualidade da experiência, satisfação e custos.
Universidade de Berna, Suíça
OneSource, Consultoria Informática, Lda.