4,145 research outputs found

    Towards automated test and validation of SIP solutions

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    IP networks are currently the major communication infrastructure used by an increasing number of applications and heterogeneous services, including voice services. In this context, the Session Initiation Protocol (SIP) is a signaling protocol widely used for controlling multimedia communication sessions such as voice or video calls over IP networks, thus performing vital functions in an extensive set of public and enter- prise solutions. However, the SIP protocol dissemination also entails some challenges, such as the complexity associated with the testing/validation processes of IMS/SIP networks. As a consequence, manual IMS/SIP testing solutions are inherently costly and time consuming tasks, being crucial to develop automated approaches in this specific area. In this perspective, this article presents an experimental approach for automated testing/validation of SIP scenarios in IMS networks. For that purpose, an automation framework is proposed allowing to replicate the configuration of SIP equipment from the pro- duction network and submit such equipment to a battery of tests in the testing network. The proposed solution allows to drastically reduce the test and validation times when compared with traditional manual approaches, also allowing to enhance testing reliability and coverage. The automation framework comprises of some freely available tools which are conveniently integrated with other specific modules implemented within the context of this work. In order to illustrate the advantages of the proposed automated framework, a real case study taken from a PT Inovação customer is presented comparing the time required to perform a manual SIP testing approach with the one time required when using the proposed auto- mated framework. The presented results clearly corroborate the advantages of using the presented framework.This work has been supported by FCT - Fundação para a CiĂȘncia e Tecnologia within the Project Scope: PEstOE/EEI/UI0319/2014. This research work was developed within the collaboration of PT Inovação (http://www.ptinovacao.pt/ en/)

    Digital Preservation Services : State of the Art Analysis

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    Research report funded by the DC-NET project.An overview of the state of the art in service provision for digital preservation and curation. Its focus is on the areas where bridging the gaps is needed between e-Infrastructures and efficient and forward-looking digital preservation services. Based on a desktop study and a rapid analysis of some 190 currently available tools and services for digital preservation, the deliverable provides a high-level view on the range of instruments currently on offer to support various functions within a preservation system.European Commission, FP7peer-reviewe

    Algorithms for advance bandwidth reservation in media production networks

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    Media production generally requires many geographically distributed actors (e.g., production houses, broadcasters, advertisers) to exchange huge amounts of raw video and audio data. Traditional distribution techniques, such as dedicated point-to-point optical links, are highly inefficient in terms of installation time and cost. To improve efficiency, shared media production networks that connect all involved actors over a large geographical area, are currently being deployed. The traffic in such networks is often predictable, as the timing and bandwidth requirements of data transfers are generally known hours or even days in advance. As such, the use of advance bandwidth reservation (AR) can greatly increase resource utilization and cost efficiency. In this paper, we propose an Integer Linear Programming formulation of the bandwidth scheduling problem, which takes into account the specific characteristics of media production networks, is presented. Two novel optimization algorithms based on this model are thoroughly evaluated and compared by means of in-depth simulation results

    Assessing and Improving Interoperability of Distributed Systems

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    InteroperabilitĂ€t von verteilten Systemen ist eine Grundlage fĂŒr die Entwicklung von neuen und innovativen GeschĂ€ftslösungen. Sie erlaubt es existierende Dienste, die auf verschiedenen Systemen angeboten werden, so miteinander zu verknĂŒpfen, dass neue oder erweiterte Dienste zur VerfĂŒgung gestellt werden können. Außerdem kann durch diese Integration die ZuverlĂ€ssigkeit von Diensten erhöht werden. Das Erreichen und Bewerten von InteroperabilitĂ€t stellt jedoch eine finanzielle und zeitliche Herausforderung dar. Zur Sicherstellung und Bewertung von InteroperabilitĂ€t werden systematische Methoden benötigt. Um systematisch InteroperabilitĂ€t von Systemen erreichen und bewerten zu können, wurde im Rahmen der vorliegenden Arbeit ein Prozess zur Verbesserung und Beurteilung von InteroperabilitĂ€t (IAI) entwickelt. Der IAI-Prozess beinhaltet drei Phasen und kann die InteroperabilitĂ€t von verteilten, homogenen und auch heterogenen Systemen bewerten und verbessern. Die Bewertung erfolgt dabei durch InteroperabilitĂ€tstests, die manuell oder automatisiert ausgefĂŒhrt werden können. FĂŒr die Automatisierung von InteroperabilitĂ€tstests wird eine neue Methodik vorgestellt, die einen Entwicklungsprozess fĂŒr automatisierte InteroperabilitĂ€tstestsysteme beinhaltet. Die vorgestellte Methodik erleichtert die formale und systematische Bewertung der InteroperabilitĂ€t von verteilten Systemen. Im Vergleich zur manuellen PrĂŒfung von InteroperabilitĂ€t gewĂ€hrleistet die hier vorgestellte Methodik eine höhere Testabdeckung, eine konsistente TestdurchfĂŒhrung und wiederholbare InteroperabilitĂ€tstests. Die praktische Anwendbarkeit des IAI-Prozesses und der Methodik fĂŒr automatisierte InteroperabilitĂ€tstests wird durch drei Fallstudien belegt. In der ersten Fallstudie werden Prozess und Methodik fĂŒr Internet Protocol Multimedia Subsystem (IMS) Netzwerke instanziiert. Die InteroperabilitĂ€t von IMS-Netzwerken wurde bisher nur manuell getestet. In der zweiten und dritten Fallstudie wird der IAI-Prozess zur Beurteilung und Verbesserung der InteroperabilitĂ€t von Grid- und Cloud-Systemen angewendet. Die Bewertung und Verbesserung dieser InteroperabilitĂ€t ist eine Herausforderung, da Grid- und Cloud-Systeme im Gegensatz zu IMS-Netzwerken heterogen sind. Im Rahmen der Fallstudien werden Möglichkeiten fĂŒr Integrations- und InteroperabilitĂ€tslösungen von Grid- und Infrastructure as a Service (IaaS) Cloud-Systemen sowie von Grid- und Platform as a Service (PaaS) Cloud-Systemen aufgezeigt. Die vorgestellten Lösungen sind in der Literatur bisher nicht dokumentiert worden. Sie ermöglichen die komplementĂ€re Nutzung von Grid- und Cloud-Systemen, eine vereinfachte Migration von Grid-Anwendungen in ein Cloud-System sowie eine effiziente Ressourcennutzung. Die InteroperabilitĂ€tslösungen werden mit Hilfe des IAI-Prozesses bewertet. Die DurchfĂŒhrung der Tests fĂŒr Grid-IaaS-Cloud-Systeme erfolgte manuell. Die InteroperabilitĂ€t von Grid-PaaS-Cloud-Systemen wird mit Hilfe der Methodik fĂŒr automatisierte InteroperabilitĂ€tstests bewertet. InteroperabilitĂ€tstests und deren Beurteilung wurden bisher in der Grid- und Cloud-Community nicht diskutiert, obwohl sie eine Basis fĂŒr die Entwicklung von standardisierten Schnittstellen zum Erreichen von InteroperabilitĂ€t zwischen Grid- und Cloud-Systemen bieten.Achieving interoperability of distributed systems offers means for the development of new and innovative business solutions. Interoperability allows the combination of existing services provided on different systems, into new or extended services. Such an integration can also increase the reliability of the provided service. However, achieving and assessing interoperability is a technical challenge that requires high effort regarding time and costs. The reasons are manifold and include differing implementations of standards as well as the provision of proprietary interfaces. The implementations need to be engineered to be interoperable. Techniques that assess and improve interoperability systematically are required. For the assurance of reliable interoperation between systems, interoperability needs to be assessed and improved in a systematic manner. To this aim, we present the Interoperability Assessment and Improvement (IAI) process, which describes in three phases how interoperability of distributed homogeneous and heterogeneous systems can be improved and assessed systematically. The interoperability assessment is achieved by means of interoperability testing, which is typically performed manually. For the automation of interoperability test execution, we present a new methodology including a generic development process for a complete and automated interoperability test system. This methodology provides means for a formalized and systematic assessment of systems' interoperability in an automated manner. Compared to manual interoperability testing, the application of our methodology has the following benefits: wider test coverage, consistent test execution, and test repeatability. We evaluate the IAI process and the methodology for automated interoperability testing in three case studies. Within the first case study, we instantiate the IAI process and the methodology for Internet Protocol Multimedia Subsystem (IMS) networks, which were previously assessed for interoperability only in a manual manner. Within the second and third case study, we apply the IAI process to assess and improve the interoperability of grid and cloud computing systems. Their interoperability assessment and improvement is challenging, since cloud and grid systems are, in contrast to IMS networks, heterogeneous. We develop integration and interoperability solutions for grids and Infrastructure as a Service (IaaS) clouds as well as for grids and Platform as a Service (PaaS) clouds. These solutions are unique and foster complementary usage of grids and clouds, simplified migration of grid applications into the cloud, as well as efficient resource utilization. In addition, we assess the interoperability of the grid-cloud interoperability solutions. While the tests for grid-IaaS clouds are performed manually, we applied our methodology for automated interoperability testing for the assessment of interoperability to grid-PaaS cloud interoperability successfully. These interoperability assessments are unique in the grid-cloud community and provide a basis for the development of standardized interfaces improving the interoperability between grids and clouds

    BlogForever: D3.1 Preservation Strategy Report

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    This report describes preservation planning approaches and strategies recommended by the BlogForever project as a core component of a weblog repository design. More specifically, we start by discussing why we would want to preserve weblogs in the first place and what it is exactly that we are trying to preserve. We further present a review of past and present work and highlight why current practices in web archiving do not address the needs of weblog preservation adequately. We make three distinctive contributions in this volume: a) we propose transferable practical workflows for applying a combination of established metadata and repository standards in developing a weblog repository, b) we provide an automated approach to identifying significant properties of weblog content that uses the notion of communities and how this affects previous strategies, c) we propose a sustainability plan that draws upon community knowledge through innovative repository design

    A method to Formalise the Rapid Prototyping Process

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    Facing the increasing complexity of the product design area, (reduction of cycle times, introduction of simultaneous engineering, introduction of digital mock-up, ... ) a research department which wants to define a rapid prototyping process is confronted to the problem of the tools’ choice. Therefore, we will propose in this article, a method allowing to conceive such a process. In a first chapter, we present the rapid prototyping area in the product design environment, in a second chapter we will propose our method illustrated by an industrial case

    Deploying an NFV-Based Experimentation Scenario for 5G Solutions in Underserved Areas

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    Presently, a significant part of the world population does not have Internet access. The fifth-generation cellular network technology evolution (5G) is focused on reducing latency, increasing the available bandwidth, and enhancing network performance. However, researchers and companies have not invested enough effort into the deployment of the Internet in remote/rural/undeveloped areas for different techno-economic reasons. This article presents the result of a collaboration between Brazil and the European Union, introducing the steps designed to create a fully operational experimentation scenario with the main purpose of integrating the different achievements of the H2020 5G-RANGE project so that they can be trialed together into a 5G networking use case. The scenario encompasses (i) a novel radio access network that targets a bandwidth of 100 Mb/s in a cell radius of 50 km, and (ii) a network of Small Unmanned Aerial Vehicles (SUAV). This set of SUAVs is NFV-enabled, on top of which Virtual Network Functions (VNF) can be automatically deployed to support occasional network communications beyond the boundaries of the 5G-RANGE radio cells. The whole deployment implies the use of a virtual private overlay network enabling the preliminary validation of the scenario components from their respective remote locations, and simplifying their subsequent integration into a single local demonstrator, the configuration of the required GRE/IPSec tunnels, the integration of the new 5G-RANGE physical, MAC and network layer components and the overall validation with voice and data services

    Beyond OAIS : towards a reliable and consistent digital preservation implementation framework

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    Current work in digital preservation (DP) is dominated by the "Open Archival Information System" (OAIS) reference framework specified by the international standard ISO 14721:2003. This is a useful aid to understanding the concepts, main functional components and the basic data flows within a DP system, but does not give specific guidance on implementation-level issues. In this paper we suggest that there is a need for a reference architecture which goes beyond OAIS to address such implementationlevel issues - to specify minimum requirements in respect of the policies, processes, and metadata required to measure and validate repository trustworthiness in respect of the authenticity, integrity, renderability, meaning, and retrievability of the digital materials preserved. The suggestion is not that a particular way of implementing OAIS be specified, but, rather that general guidelines on implementation are required if the term 'OAIS-compliant' is to be meaningful in the sense of giving an assurance of attaining and maintaining an operationally adequate or better level of long-term reliability, consistency, and crosscompatibility in implemented DP systems that is measurable, verifiable, manageable, and (as far as possible) futureproofed
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