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• Description

Context

Due to the multiplication of video based services and to the use of higher definition coding methods, a large
and increasing portion of network traffic is related to video services. In addition, actors of the video
chain require the best possible video quality with constraints on the zapping time (channel switching), the
buffering delay, playback facilities, etc. Network operators control the performance of their network in order
to satisfy their users. Ultimately, the goal of network operators is that for each application, the Quality of
Experience (QoE) is good.

However, network operators have little control on the traffic generated by video services, unless they explicitly manage the video distribution services. If a distant network server or an independent Content Delivery Network (CDN) manages the distribution, the network cannot engineer the traffic distributed by the CDN since it does not interact with the CDN. In case of P2P distribution, it is even worse: the network has almost no control on P2P traffic ignoring the source address of incoming traffic. Even in the context of P4P, the network operator just provides hints and has no direct control on P2P traffic flows.

Objectives

The main objective of the present project is to provide methods allowing a network operator to have explicit control on traffic flows related to video distribution. VIPEER builds upon the collaboration between a traditional CDN and a peer-assisted CDN or "distributed CDN" (dCDN), i.e. an overlay controlled by the network operator using P2P paradigms. The peers in the dCDN may be network elements such as network nodes or boxes located at customers' premises. In the latter case, the box is actually split between a private part which is directly under the customer's control and a "public" part that is managed within the distributed overlay, by the network operator.

Although projects addressing the design of peer-assisted CDN have recently flourished, a theoretical framework describing the interactions between multiple servers and clients, and the related flow and packet management dynamics is still lacking. VIPEER aims at defining a framework, both theoretical and operational, for video distribution when distributed servers and routers exhibit resource constraints. The whole project is divided into 6 tasks.

 

Task0 PROJECT MANAGEMENT, EXPLOITATION AND DISSEMINATION

The objective of Task 0 is to carry out the project management and administrative Tasks to support the other more technically oriented work packages. The Task includes also exploitation and dissemination of the project results based on the work done in other work packages.

Task1 ARCHITECTURE

The objective of Task 1 is to define the architecture of the overall system for delivering video content with a certain level of quality of experience. The basic principle is to use storage capacities equipped with some processing capabilities in order to run algorithms, which orchestrate the content delivery.

Task2 METROLOGY

This task mainly consists of building a global measurement infrastructure in order to inform the network and QoS aware dCDN with useful information about the network state and about the end user activity. The ultimate goal is to be able to optimize the distribution strategy of the dCDN so as to minimize the impact of the dCDN on the QoS perceived by the set-top-box owners and to maximize the QoS experienced by the dCDN's users.

Task3 MEDIA HANDLING

Media handling mainly consists in adapting the media (or audio/video content) according to the distribution conditions in time. These conditions include constraints about: the bandwidth variability at different levels into the distribution path, the local quality of service (e.g packet loss on a given access network type), targeted device (interoperability) as well as content popularity. Actually, a popular content might be available into various forms in the dCDN requiring less content adaptation while a less popular content may require more content adaptation and therefore consume more resources.

Task4 DISTRIBUTED CDN

This task aims at designing the technical elements of the system which is sketched in Task 2. The major components include a CDN, a “dCDN” (a set of set-top-boxes), and the clients. The main contributions of this task include: maintaining a state-of-the-art bibliography on a flourishing scientific and applicative topic, the design of algorithms for allocating content to edge servers, either CDN or dCDN, the design of algorithms for delivering the data to the clients, and the development of several tools, both theoretical and applicative, allowing a comprehensive analysis of the proposed algorithms.

Task5 TESTS AND DEMONSTRATIONS

The objective of this work package is to design demonstration “showcases” presenting the project results from different stakeholders' point of view. We plan to use demonstrations both in the evaluation process and for dissemination purpose.