Livraison de contenus sur un réseau hybride satellite / terrestre

L’augmentation et le renforcement des usages d’Internet rend nécessaire l’évolution des réseaux existants. Cependant, on constate de fortes inégalités entre les zones urbaines, bien desservies et qui concentrent l’essentiel des investissements, et les zones rurales, mal desservies etdélaissées. Face à cette situation, les utilisateurs de ces zones se tournent vers d’autres moyensd’accès, et notamment vers les accès Internet par satellite. Cependant, ces derniers souffrentd’une limitation qui est le délai important induit par le temps de propagation du signal entre la terre et l’orbite géostationnaire. Dans cette thèse, nous nous intéressons à l’utilisation simultanée d’un réseau d’accès terrestre, caractérisé par un faible débit et un faible délai, et d’un réseau d’accès satellite, caractérisé par une forte latence et un débit plus important. D’autre part, les réseaux dediffusion de contenus ou CDNs, constitués d’un grand nombre de serveurs de cache, apportentune réponse à l’augmentation du trafic et des besoins en termes de latence et de débit.Cependant, localisés dans les réseaux de cœur, les caches restent éloignés des utilisateurs etn’atteignent pas les réseaux d’accès. Ainsi, les fournisseurs d’accès Internet (FAI) se sontintéressés au déploiement de ces serveurs au sein de leur propre réseau, que l’on appelle alorsTelCo CDN. La diffusion des contenus nécessite idéalement l’interconnexion des opérateurs CDNavec les TelCo CDNs, permettant ainsi la délégation de la diffusion à ces derniers. Ils sont alorsen mesure d’optimiser la diffusion des contenus sur leur réseau dont ils ont une meilleureconnaissance. Ainsi, nous nous intéresserons à l’optimisation de la livraison de contenus sur unréseau hybride satellite / terrestre intégré à une chaîne de livraison CDN. Nous nous attacheronsdans un premier temps à décrire une architecture permettant, grâce à l’interconnexion de CDNs,de prendre en charge la diffusion des contenus sur le réseau hybride. Dans un second temps,nous étudierons l’intérêt de la connaissance des informations apportées par le contexte CDN pour le routage sur une telle architecture. Dans ce cadre, nous proposerons un mécanisme de routage fondé sur la taille des contenus. Finalement, nous montrerons la supériorité de notre approche sur l’utilisation du protocole de transport multichemin MP-TC

QOE-AWARE CONTENT DISTRIBUTION SYSTEMS FOR ADAPTIVE BITRATE VIDEO STREAMING

A prodigious increase in video streaming content along with a simultaneous rise in end system capabilities has led to the proliferation of adaptive bit rate video streaming users in the Internet. Today, video streaming services range from Video-on-Demand services like traditional IP TV to more recent technologies such as immersive 3D experiences for live sports events. In order to meet the demands of these services, the multimedia and networking research community continues to strive toward efficiently delivering high quality content across the Internet while also trying to minimize content storage and delivery costs. The introduction of flexible and adaptable technologies such as compute and storage clouds, Network Function Virtualization and Software Defined Networking continue to fuel content provider revenue. Today, content providers such as Google and Facebook build their own Software-Defined WANs to efficiently serve millions of users worldwide, while NetFlix partners with ISPs such as ATT (using OpenConnect) and cloud providers such as Amazon EC2 to serve their content and manage the delivery of several petabytes of high-quality video content for millions of subscribers at a global scale, respectively. In recent years, the unprecedented growth of video traffic in the Internet has seen several innovative systems such as Software Defined Networks and Information Centric Networks as well as inventive protocols such as QUIC, in an effort to keep up with the effects of this remarkable growth. While most existing systems continue to sub-optimally satisfy user requirements, future video streaming systems will require optimal management of storage and bandwidth resources that are several orders of magnitude larger than what is implemented today. Moreover, Quality-of-Experience metrics are becoming increasingly fine-grained in order to accurately quantify diverse content and consumer needs. In this dissertation, we design and investigate innovative adaptive bit rate video streaming systems and analyze the implications of recent technologies on traditional streaming approaches using real-world experimentation methods. We provide useful insights for current and future content distribution network administrators to tackle Quality-of-Experience dilemmas and serve high quality video content to several users at a global scale. In order to show how Quality-of-Experience can benefit from core network architectural modifications, we design and evaluate prototypes for video streaming in Information Centric Networks and Software-Defined Networks. We also present a real-world, in-depth analysis of adaptive bitrate video streaming over protocols such as QUIC and MPQUIC to show how end-to-end protocol innovation can contribute to substantial Quality-of-Experience benefits for adaptive bit rate video streaming systems. We investigate a cross-layer approach based on QUIC and observe that application layer-based information can be successfully used to determine transport layer parameters for ABR streaming applications

OpenCache:a content delivery platform for the modern internet

Since its inception, the World Wide Web has revolutionised the way we share information, keep in touch with each other and consume content. In the latter case, it is now used by thousands of simultaneous users to consume video, surpassing physical media as the primary means of distribution. With the rise of on-demand services and more recently, high-definition media, this popularity has not waned. To support this consumption, the underlying infrastructure has been forced to evolve at a rapid pace. This includes the technology and mechanisms to facilitate the transmission of video, which are now offered at varying levels of quality and resolution. Content delivery networks are often deployed in order to scale the distribution provision. These vary in nature and design; from third-party providers running entirely as a service to others, to in-house solutions owned by the content service providers themselves. However, recent innovations in networking and virtualisation, namely Software Defined Networking and Network Function Virtualisation, have paved the way for new content delivery infrastructure designs. In this thesis, we discuss the motivation behind OpenCache, a next-generation content delivery platform. We examine how we can leverage these emerging technologies to provide a more flexible and scalable solution to content delivery. This includes analysing the feasibility of novel redirection techniques, and how these compare to existing means. We also investigate the creation of a unified interface from which a platform can be precisely controlled, allowing new applications to be created that operate in harmony with the infrastructure provision. Developments in distributed virtualisation platforms also enables functionality to be spread throughout a network, influencing the design of OpenCache. Through a prototype implementation, we evaluate each of these facets in a number of different scenarios, made possible through deployment on large-scale testbeds

Content Replication and Placement Schemes for Wireless Mesh Networks

Recently, Wireless Mesh Networks (WMNs) have attracted much of interest from both academia and industry, due to their potential to provide an alternative broadband wireless Internet connectivity. However, due to different reasons such as multi-hop forwarding and the dynamic wireless link characteristics, the performance of current WMNs is rather low when clients are soliciting Web contents. Due to the evolution of advanced mobile computing devices; it is anticipated that the demand for bandwidth-onerous popular content (especially multimedia content) in WMNs will dramatically increase in the coming future. Content replication is a popular approach for outsourcing content on behalf of the origin content provider. This area has been well explored in the context of the wired Internet, but has received comparatively less attention from the research community when it comes to WMNs. There are a number of replica placement algorithms that are specifically designed for the Internet. But they do not consider the special features of wireless networks such as insufficient bandwidth, low server capacity, contention to access the wireless medium, etc. This thesis studies the technical challenges encountered when transforming the traditional model of multi-hop WMNs from an access network into a content network. We advance the thesis that support from packet relaying mesh routers to act as replica servers for popular content such as media streaming, results in significant performance improvement. Such support from infrastructure mesh routers benefits from knowledge of the underlying network topology (i.e., information about the physical connections between network nodes is available at mesh routers). The utilization of cross-layer information from lower layers opens the door to developing efficient replication schemes that account for the specific features of WMNs (e.g., contention between the nodes to access the wireless medium and traffic interference). Moreover, this can benefit from the underutilized resources (e.g., storage and bandwidth) at mesh routers. This utilization enables those infrastructure nodes to participate in content distribution and play the role of replica servers. In this thesis, our main contribution is the design of two lightweight, distributed, and scalable object replication schemes for WMNs. The first scheme follows a hierarchical approach, while the second scheme follows a flat one. The challenge is to replicate content as close as possible to the requesting clients and thus, reduce the access latency per object, while minimizing the number of replicas. The two schemes aim to address the questions of where and how many replicas should be placed in the WMN. In our schemes, we consider the underlying topology joint with link-quality metrics to improve the quality of experience. We show using simulation tests that the schemes significantly enhance the performance of a WMN in terms of reducing the access cost, bandwidth consumption and computation/communication cost

5GAuRA. D3.3: RAN Analytics Mechanisms and Performance Benchmarking of Video, Time Critical, and Social Applications

5GAuRA deliverable D3.3.This is the final deliverable of Work Package 3 (WP3) of the 5GAuRA project, providing a report on the project’s developments on the topics of Radio Access Network (RAN) analytics and application performance benchmarking. The focus of this deliverable is to extend and deepen the methods and results provided in the 5GAuRA deliverable D3.2 in the context of specific use scenarios of video, time critical, and social applications. In this respect, four major topics of WP3 of 5GAuRA – namely edge-cloud enhanced RAN architecture, machine learning assisted Random Access Channel (RACH) approach, Multi-access Edge Computing (MEC) content caching, and active queue management – are put forward. Specifically, this document provides a detailed discussion on the service level agreement between tenant and service provider in the context of network slicing in Fifth Generation (5G) communication networks. Network slicing is considered as a key enabler to 5G communication system. Legacy telecommunication networks have been providing various services to all kinds of customers through a single network infrastructure. In contrast, by deploying network slicing, operators are now able to partition one network into individual slices, each with its own configuration and Quality of Service (QoS) requirements. There are many applications across industry that open new business opportunities with new business models. Every application instance requires an independent slice with its own network functions and features, whereby every single slice needs an individual Service Level Agreement (SLA). In D3.3, we propose a comprehensive end-to-end structure of SLA between the tenant and the service provider of sliced 5G network, which balances the interests of both sides. The proposed SLA defines reliability, availability, and performance of delivered telecommunication services in order to ensure that right information is delivered to the right destination at right time, safely and securely. We also discuss the metrics of slicebased network SLA such as throughput, penalty, cost, revenue, profit, and QoS related metrics, which are, in the view of 5GAuRA, critical features of the agreement.Peer ReviewedPostprint (published version

Dynamic content delivery infrastructure deployment using network cloud resources

Millionen von Menschen schätzen die Inhalte und Anwendungen, die das Internet zur Verfügung stellt. Um der steigenden Nachfrage an populären Inhalten wie z.B. High-Definition Video oder Online Social Networks nachzukommen, wurden weit verteilte Content Delivery Infrastructures (CDIs) aufgebaut. Damit CDIs im harten Wettbewerbs bestehen können, suchen sie ständig neue Möglichkeiten um laufende Kosten zu senken und Ihre Leistungsfähigkeit zu steigern. Jedoch machen den CDIs eine geringe Agilität bei der Allokation von Servern zu schaffen. Informationen zur Steigerung von Effizienz und Leistungsfähigkeit wie z.B. aktuelle Netzwerkbedingungen und präzise User-Positionen sind den CDIs unbekannt. Obwohl Internet Service Provider (ISPs) diese Informationen besitzen, lassen auch neuere CDI-Architekturen eine mögliche Kollaboration außer Acht. Diese Dissertation untersucht den Einfluss von Kollaboration auf Content Delivery. Zunächst wird das heutige Design- und Betriebsfeld untersucht. Eine Analyse der operativen Daten eines Europäischen Tier-1 ISPs erörtert mögliche Verbesserungen. Erste Ergebnisse zeigen, dass Kollaboration bei der Zuordnung von Usern zu CDI Servern den Netzwerkverkehr lokal begrenzt und die Geschwindigkeit erhöht. Vorhandene Netzwerkpfade eröffnen neue Möglichkeiten der Verkehrssteuerung. Um die Kollaboration zwischen CDIs und ISPs zu ermöglichen, beschreibt diese Arbeit die beiden Key Enabler In-Network Server Allocation und Informed User-Server Assignment. Sie stellt außerdem ein Systemdesign vor, das diese realisiert: NetPaaS (Network Platform as a Service). In-Network Server Allocation nutzt im ISP verteilte Resourcen und aktuelle Virtualisierungstechnologien um eine agile Serverallokation zu ermöglichen. Informed User-Server Assignment erlaubt es ISPs, mögliche Netzwerkengpässe und präzise User-Positionen einzukalkulieren und so CDIs den besten Server für individuelle Nutzer zu empfehlen. Damit bietet NetPaaS einen zusätzlichen Freiheitsgrad zur dynamischen Skalierung von Serverinfrastrukturen. Um das Kollaborationspotential von NetPaaS aufzuzeigen, wird erstmals eine Studie mit operativen Daten des größten kommerziellen CDI und einem Europäischen Tier-1 ISP durchgeführt. Die Ergebniss zeigen, dass eine auf präzisen User-Positionen und aktuellen Netzwerkbedingungen basierende dynamische Serverallokation es dem CDI ermöglicht, besser mit der stark schwankenden Nachfrage nach Inhalten zurecht zu kommen und die Geschwindigkeit der Nutzer zu verbessern. Darüber hinaus führt die Nutzung von NetPaaS zu einer besseren Auslastung vorhandener Serverinfrastrukturen und ermöglicht ein verbessertes Verkehrsmanagement im Netz des ISP. Diese Ergebnisse lassen den Schluss zu, dass NetPaaS die Leistungsfähigkeit und Effizienz von CDIs stark verbessert und unter Umständen laufende Kosten und Investitionen reduziert. NetPaaS verbessert weiterhin das Verkehrsmanagement des ISP und bietet somit eine echte "win-win" Situation fur CDIs und ISPs.Millions of people value the Internet for the content and the applications it makes available. To cope with the increasing end-user demand for popular and often high volume content, e.g., high-definition video or online social networks, massively distributed Content Delivery Infrastructures (CDIs) have been deployed. However, a highly competitive market requires CDIs to constantly investigate new ways to reduce operational costs and improve delivery performance. Today, CDIs mainly suffer from limited agility in server deployment and are largely unaware of network conditions and precise end-user locations, information that improves the efficiency and performance of content delivery. While newly emerging architectures try to address these challenges, none so far considered collaboration, although ISPs have the information readily at hand. In this thesis, we assess the impact of collaboration on content delivery. We first evaluate the design and operating space of todays content delivery landscape and quantify possible benefits of collaboration by analyzing operational traces from an European Tier-1 ISP. We find that collaboration when assigning end-users to servers highly localizes CDI traffic and improves end-user performance. Moreover, we find significant path diversity which enables new mechanisms for traffic management. We propose two key enablers, namely in-network server allocation and informed user-server assignment, to facilitate CDI-ISP collaboration and present our system design, called NetPaaS (Network Platform as a Service), that realizes them. In- network server allocation offers agile server allocation close to the ISPs end-users leveraging virtualization technology and cloud style resources in the network. In- formed user-server assignment enables ISPs to take network bottlenecks and precise end-user locations into account and to recommend the best possible candidate server for individual end-users to CDIs. Therefore, NetPaaS provides an additional degree of freedom to scale-up or shrink the CDI footprint on demand. To quantify the potential of collaboration with NetPaaS, we perform a first-of-its- kind evaluation based on operational traces from the largest commercial CDI and an European Tier-1 ISP. Our findings reveal that dynamic server allocation based on accurate end-user locations and network conditions enables the CDI to better cope with increasing and highly volatile demand for content and improves the end-users performance. Moreover, recommendations from NetPaaS result in better utilization of existing server infrastructure and enables the ISP to better manage traffic flows inside its network. We conclude, that NetPaaS improves the performance and efficiency of content delivery architectures while potentially reducing the required capital investment and operational costs. Moreover, NetPaaS enables the ISP to achieve traffic engineering goals and therefore offers a true win-win situation to both CDIs and ISPs

Enabling Multipath and Multicast Data Transmission in Legacy and Future Internet

The quickly growing community of Internet users is requesting multiple applications and services. At the same time the structure of the network is changing. From the performance point of view, there is a tight interplay between the application and the network design. The network must be constructed to provide an adequate performance of the target application. In this thesis we consider how to improve the quality of users' experience concentrating on two popular and resource-consuming applications: bulk data transfer and real-time video streaming. We share our view on the techniques which enable feasibility and deployability of the network functionality leading to unquestionable performance improvement for the corresponding applications. Modern mobile devices, equipped with several network interfaces, as well as multihomed residential Internet hosts are capable of maintaining multiple simultaneous attachments to the network. We propose to enable simultaneous multipath data transmission in order to increase throughput and speed up such bandwidth-demanding applications as, for example, file download. We design an extension for Host Identity Protocol (mHIP), and propose a multipath data scheduling solution on a wedge layer between IP and transport, which effectively distributes packets from a TCP connection over available paths. We support our protocol with a congestion control scheme and prove its ability to compete in a friendly manner against the legacy network protocols. Moreover, applying game-theoretic analytical modelling we investigate how the multihomed HIP multipath-enabled hosts coexist in the shared network. The number of real-time applications grows quickly. Efficient and reliable transport of multimedia content is a critical issue of today's IP network design. In this thesis we solve scalability issues of the multicast dissemination trees controlled by the hybrid error correction. We propose a scalable multicast architecture for potentially large overlay networks. Our techniques address suboptimality of the adaptive hybrid error correction (AHEC) scheme in the multicast scenarios. A hierarchical multi-stage multicast tree topology is constructed in order to improve the performance of AHEC and guarantee QoS for the multicast clients. We choose an evolutionary networking approach that has the potential to lower the required resources for multimedia applications by utilizing the error-correction domain separation paradigm in combination with selective insertion of the supplementary data from parallel networks, when the corresponding content is available. Clearly both multipath data transmission and multicast content dissemination are the future Internet trends. We study multiple problems related to the deployment of these methods.Internetin nopeasti kasvava käyttäjäkunta vaatii verkolta yhä enemmän sovelluksia ja palveluita. Samaan aikaan verkon rakenne muuttuu. Suorituskyvyn näkökulmasta on olemassa selvä vuorovaikutussovellusten ja verkon suunnittelun välillä. Verkko on rakennettava siten, että se pystyy takaamaan riittävän suorituskyvyn halutuille palveluille. Tässä väitöskirjassa pohditaan, miten verkon käyttökokemusta voidaan parantaa keskittyen kahteen suosittuun ja resursseja vaativaan sovellukseen: tiedonsiirtoon ja reaaliaikaiseen videon suoratoistoon. Esitämme näkemyksemme tekniikoista, jotka mahdollistavat tarvittavien verkkotoiminnallisuuksien helpon toteuttavuuden sekä kiistatta parantavat sovelluksien suorityskykyä. Nykyaikaiset mobiililaitteet monine verkkoyhteyksineen, kuten myös kotitietokoneet, pystyvät ylläpitämään monta internet-yhteyttä samanaikaisesti. Siksi ehdotamme monikanavaisen tiedonsiirron käyttöä suorituskyvyn parantamiseksi ja etenkin vaativien verkkosovelluksien, kuten tiedostonsiirron, nopeuttamiseksi. Tässä väitöskirjassa suunnitellaan Host Identity Protocol (mHIP) -laajennus, sekä esitetään tiedonsiirron vuorotteluratkaisu, joka hajauttaa TCP-yhteyden tiedonsiirtopaketit käytettävissä oleville kanaville. Protokollamme tueksi luomme myös ruuhkautumishallinta-algoritmin ja näytämme sen pystyvän toimimaan yhteen nykyisien verkkoprotokollien kanssa. Tämän lisäksi tutkimme peliteoreettista mallinnusta käyttäen, miten monikanavaiset HIP-verkkopäätteet toimivat muiden kanssa jaetuissa verkoissa. Reaaliaikaisten sovellusten määrä kasvaa nopeasti. Tehokas ja luotettava multimediasisällön siirto on olennainen vaatimus nykypäivän IP-verkoissa. Tässä työssä ratkaistaan monilähetyksen (multicast) jakelustruktuurin skaalautuvuuteen liittyviä ongelmia. Ehdotamme skaalautuvaa monilähetysarkkitehtuuria suurille peiteverkoille. Ratkaisumme puuttuu adaptiivisen virhekorjauksen (Adaptive Hybrid Error Correction, AHEC) alioptimaalisuuteen monilähetystilanteissa. Luomme hierarkisen monivaiheisen monilähetyspuutopologian parantaaksemme AHECin suorituskykyä, sekä taataksemme monilähetysasiakkaiden palvelun laadun. Valitsimme evoluutiomaisen lähestymistavan, jolla on potentiaalia keventää multimediasovelluksien verkkoresurssivaatimuksia erottamalla virhekorjauksen omaksi verkkotunnuksekseen, sekä käyttämällä valikoivaa täydentävää tiedonlisäystä rinnakkaisverkoista vastaavan sisällön ollessa saatavilla. Sekä monikanava- että monilähetystiedonsiirto ovat selvästi osa internetin kehityssuuntaa. Tässä väitöskirjassa tutkimme monia ongelmia näiden tekniikoiden käyttöönottoon liittyen