Pathways: Augmenting interoperability across scholarly repositories

In the emerging eScience environment, repositories of papers, datasets, software, etc., should be the foundation of a global and natively-digital scholarly communications system. The current infrastructure falls far short of this goal. Cross-repository interoperability must be augmented to support the many workflows and value-chains involved in scholarly communication. This will not be achieved through the promotion of single repository architecture or content representation, but instead requires an interoperability framework to connect the many heterogeneous systems that will exist. We present a simple data model and service architecture that augments repository interoperability to enable scholarly value-chains to be implemented. We describe an experiment that demonstrates how the proposed infrastructure can be deployed to implement the workflow involved in the creation of an overlay journal over several different repository systems (Fedora, aDORe, DSpace and arXiv).Comment: 18 pages. Accepted for International Journal on Digital Libraries special issue on Digital Libraries and eScienc

Mobile Ad-Hoc Networks

Being infrastructure-less and without central administration control, wireless ad-hoc networking is playing a more and more important role in extending the coverage of traditional wireless infrastructure (cellular networks, wireless LAN, etc). This book includes state-of the-art techniques and solutions for wireless ad-hoc networks. It focuses on the following topics in ad-hoc networks: vehicular ad-hoc networks, security and caching, TCP in ad-hoc networks and emerging applications. It is targeted to provide network engineers and researchers with design guidelines for large scale wireless ad hoc networks

Mesmerizer: A Effective Tool for a Complete Peer-to-Peer Software Development Life-cycle

In this paper we present what are, in our experience, the best practices in Peer-To-Peer(P2P) application development and how we combined them in a middleware platform called Mesmerizer. We explain how simulation is an integral part of the development process and not just an assessment tool. We then present our component-based event-driven framework for P2P application development, which can be used to execute multiple instances of the same application in a strictly controlled manner over an emulated network layer for simulation/testing, or a single application in a concurrent environment for deployment purpose. We highlight modeling aspects that are of critical importance for designing and testing P2P applications, e.g. the emulation of Network Address Translation and bandwidth dynamics. We show how our simulator scales when emulating low-level bandwidth characteristics of thousands of concurrent peers while preserving a good degree of accuracy compared to a packet-level simulator

Information Centric Networking in the IoT: Experiments with NDN in the Wild

This paper explores the feasibility, advantages, and challenges of an ICN-based approach in the Internet of Things. We report on the first NDN experiments in a life-size IoT deployment, spread over tens of rooms on several floors of a building. Based on the insights gained with these experiments, the paper analyses the shortcomings of CCN applied to IoT. Several interoperable CCN enhancements are then proposed and evaluated. We significantly decreased control traffic (i.e., interest messages) and leverage data path and caching to match IoT requirements in terms of energy and bandwidth constraints. Our optimizations increase content availability in case of IoT nodes with intermittent activity. This paper also provides the first experimental comparison of CCN with the common IoT standards 6LoWPAN/RPL/UDP.Comment: 10 pages, 10 figures and tables, ACM ICN-2014 conferenc

Flexible Application-Layer Multicast in Heterogeneous Networks

This work develops a set of peer-to-peer-based protocols and extensions in order to provide Internet-wide group communication. The focus is put to the question how different access technologies can be integrated in order to face the growing traffic load problem. Thereby, protocols are developed that allow autonomous adaptation to the current network situation on the one hand and the integration of WiFi domains where applicable on the other hand

On Data Dissemination for Large-Scale Complex Critical Infrastructures

Middleware plays a key role for the achievement of the mission of future largescalecomplexcriticalinfrastructures, envisioned as federations of several heterogeneous systems over Internet. However, available approaches for datadissemination result still inadequate, since they are unable to scale and to jointly assure given QoS properties. In addition, the best-effort delivery strategy of Internet and the occurrence of node failures further exacerbate the correct and timely delivery of data, if the middleware is not equipped with means for tolerating such failures. This paper presents a peer-to-peer approach for resilient and scalable datadissemination over large-scalecomplexcriticalinfrastructures. The approach is based on the adoption of epidemic dissemination algorithms between peer groups, combined with the semi-active replication of group leaders to tolerate failures and assure the resilient delivery of data, despite the increasing scale and heterogeneity of the federated system. The effectiveness of the approach is shown by means of extensive simulation experiments, based on Stochastic Activity Networks

A Novel Approach to Load Balancing in P2P Overlay Networks for Edge Systems

Edge computing aims at addressing some limitations of cloud computing by bringing computation towards the edge of the system, i.e., closer to the client. There is a panoply of devices that can be integrated into future edge computing platforms, from local datacenters and ISP points of presence, to 5G towers, and even, multiple user devices like smartphones, laptops, and IoT devices. For all of these devices to communicate fruitfully, we need to build systems that enable the seamless interaction and cooperation among these diverse devices. However, creating and maintaining these systems is not trivial since there are numerous types of devices with different capacities. This resource heterogeneity has to be taken into account so that different types of machines contribute to the management of the distributed infrastructure differently, and the operation of the overall system becomes more efficient. In this work, we addressed the challenges identified above by exploring unstructured overlay networks, that have been shown to be possible to manage efficiently and in a fully decentralized way, while being highly robust to failures. To that end, we devised a solution that adapts the number of neighbors of each device (i.e., how many other devices that device knows) according to the capacity of that device and the distribution of capacities of the other devices in the network, as to ensure that the load is fairly distributed between them and, as a consequence, improve the operation of other services atop the unstructured overlay network, for instance, reducing the latencies experienced when broadcasting information. This solution can be easily integrated into most existing peer-to-peer distributed systems, requiring just a slight adaptation to their membership protocol. To show the correction and benefits of our proposal, we evaluated it by comparing it with state of the art decentralized solutions to manage unstructured overlay networks, combining both simulation (to observe the performance of the solution at large scale) and prototype deployments in realistic distributed infrastructures.A computação de periferia visa abordar algumas limitações da computação em nuvem, trazendo a computação para mais perto do cliente. Há uma enorme variedade de dispositivos que podem ser integrados em futuras plataformas de computação de periferia, de data centers locais e pontos de presença de ISPs a torres 5G e até mesmo dispositivos de cliente, como smartphones, laptops e dispositivos IoT. Para que todos esses dispositivos comuniquem de forma proveitosa entre si, precisamos construir sistemas que possibilitem a interação e cooperação eficaz entre eles. No entanto, criar e manter esses sistemas não é trivial, uma vez que existem vários tipos de dispositivos com diferentes capacidades. Essa heterogeneidade de recursos deve ser levada em consideração para que diferentes tipos de máquinas contribuam para o gerenciamento da infraestrutura distribuída de forma distinta e a operação do sistema se torne mais eficiente. Neste trabalho, enfrentámos os desafios identificados acima explorando redes sobrepostas não estruturadas, que se têm mostrado possíveis de gerenciar de forma eficiente e totalmente descentralizada, sendo altamente resistentes a falhas. Para tal, concebemos uma solução que adapta o número de vizinhos de cada dispositivo (ou seja, quantos outros dispositivos aquele dispositivo conhece) de acordo com a sua capacidade e a capacidade dos demais dispositivos da rede, de forma a garantir que a carga seja proporcionalmente distribuída entre eles e, como consequência, reduzindo as latências experienciadas por esses dispositivos. Esta solução pode ser facilmente integrada num sistema distribuído entre-pares existente, exigindo apenas uma ligeira adaptação ao seu protocolo de filiação. Avaliámos a nossa solução comparando-a com outras soluções descentralizadas de última geração, combinando simulação (para observar o desempenho da soluç

Broadcasting in Prefix Space: P2P Data Dissemination with Predictable Performance

A broadcast mode may augment peer-to-peer overlay networks with an efficient, scalable data replication function, but may also give rise to a virtual link layer in VPN-type solutions. We introduce a simple broadcasting mechanism that operates in the prefix space of distributed hash tables without signaling. This paper concentrates on the performance analysis of the prefix flooding scheme. Starting from simple models of recursive $k$-ary trees, we analytically derive distributions of hop counts and the replication load. Extensive simulation results are presented further on, based on an implementation within the OverSim framework. Comparisons are drawn to Scribe, taken as a general reference model for group communication according to the shared, rendezvous-point-centered distribution paradigm. The prefix flooding scheme thereby confirmed its widely predictable performance and consistently outperformed Scribe in all metrics. Reverse path selection in overlays is identified as a major cause of performance degradation.Comment: final version for ICIW'0

Wired/Wireless Compound Networking

International audienceThis chapter explores techniques that enable efficient link state routing on compound networks. These techniques rely on the selection and maintenance of a subset of links in the network (i.e. an overlay) along which the different operations of link-state routing can be performed more efficiently. This chapter provides a formal analysis of such techniques, a qualitative evaluation of their specific properties and example applications of such techniques with a standard routing protocol