144 research outputs found

    On the Notion of Abstract Platform in MDA Development

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    Although platform-independence is a central property in MDA models, the study of platform-independence has been largely overlooked in MDA. As a consequence, there is a lack of guidelines to select abstraction criteria and modelling concepts for platform-independent design. In addition, there is little methodological support to distinguish between platform-independent and platform-specific concerns, which could be detrimental to the beneficial exploitation of the PIM-PSM separation-of-concerns adopted by MDA. This work is an attempt towards clarifying the notion of platform-independent modelling in MDA development. We argue that each level of platform-independence must be accompanied by the identification of an abstract platform. An abstract platform is determined by the platform characteristics that are relevant for applications at a certain level of platform-independence, and must be established by balancing various design goals. We present some methodological principles for abstract platform design, which forms a basis for defining requirements for design languages intended to support platform-independent design. Since our methodological framework is based on the notion of abstract platform, we pay particular attention to the definition of abstract platforms and the language requirements to specify abstract platforms. We discuss how the concept of abstract platform relates to UML

    Formal Specification of QoS Negotiation in ODP System

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    The future of Open Distributed Processing systems (ODP) will see an increasing of components number, these components are sharing resources. In general, these resources are offering some kind of services. Due to the huge number of components, it is very difficult to offer the optimum Quality of service (QoS). This encourages us to develop a model for QoS negotiation process to optimize the QoS in an ODP system. In such system, there is a High risk of software or hardware failure. To ensure good performance of a system based on our model, we develop it using a formal method. In our case, we will use Event-B to get in the end of our development a system correct by construction

    Security and management policy specification

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    A Survey on the Contributions of Software-Defined Networking to Traffic Engineering

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    Since the appearance of OpenFlow back in 2008, software-defined networking (SDN) has gained momentum. Although there are some discrepancies between the standards developing organizations working with SDN about what SDN is and how it is defined, they all outline traffic engineering (TE) as a key application. One of the most common objectives of TE is the congestion minimization, where techniques such as traffic splitting among multiple paths or advanced reservation systems are used. In such a scenario, this manuscript surveys the role of a comprehensive list of SDN protocols in TE solutions, in order to assess how these protocols can benefit TE. The SDN protocols have been categorized using the SDN architecture proposed by the open networking foundation, which differentiates among data-controller plane interfaces, application-controller plane interfaces, and management interfaces, in order to state how the interface type in which they operate influences TE. In addition, the impact of the SDN protocols on TE has been evaluated by comparing them with the path computation element (PCE)-based architecture. The PCE-based architecture has been selected to measure the impact of SDN on TE because it is the most novel TE architecture until the date, and because it already defines a set of metrics to measure the performance of TE solutions. We conclude that using the three types of interfaces simultaneously will result in more powerful and enhanced TE solutions, since they benefit TE in complementary ways.European Commission through the Horizon 2020 Research and Innovation Programme (GN4) under Grant 691567 Spanish Ministry of Economy and Competitiveness under the Secure Deployment of Services Over SDN and NFV-based Networks Project S&NSEC under Grant TEC2013-47960-C4-3-

    Software engineering and middleware: a roadmap (Invited talk)

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    The construction of a large class of distributed systems can be simplified by leveraging middleware, which is layered between network operating systems and application components. Middleware resolves heterogeneity and facilitates communication and coordination of distributed components. Existing middleware products enable software engineers to build systems that are distributed across a local-area network. State-of-the-art middleware research aims to push this boundary towards Internet-scale distribution, adaptive and reconfigurable middleware and middleware for dependable and wireless systems. The challenge for software engineering research is to devise notations, techniques, methods and tools for distributed system construction that systematically build and exploit the capabilities that middleware deliver

    Web Services Support for Dynamic Business Process Outsourcing

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    Outsourcing of business processes is crucial for organizations to be effective, efficient and flexible. To meet fast-changing market conditions, dynamic outsourcing is required, in which business relationships are established and enacted on-the-fly in an adaptive, fine-grained way unrestricted by geographic distance. This requires automated means for both the establishment of outsourcing relationships and for the enactment of services performed in these relationships over electronic channels. Due to wide industry support and the underlying model of loose coupling of services, Web services increasingly become the mechanism of choice to connect organizations across organizational boundaries. This paper analyzes to which extent Web services support the dynamic process outsourcing paradigm. We discuss contract -based dynamic business process outsourcing to define requirements and then introduce the Web services framework. Based on this, we investigate the match between the two. We observe that the Web services framework requires further support for cross - organizational business processes and mechanisms for contracting, QoS management and process-based transaction support and suggest ways to fill those gaps

    Design of a Teleworking Service Using Parlay Framework Federation

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    Faculty of Engineering and Built Enviroment School of Electrical and Information Engineering 0314356t [email protected] teleworking service allows people to work effectively together from home or other approved locations away from the regular work site, on an established work schedule. This is made possible via the use of Information and Communications Technology (ICT). Presently, there are isolated applications that can assist teleworkers, such as e-mail and video conferencing, which were developed for use over the Internet. But the Internet is a best-effort network with no guarantee of Quality of service (QoS), low security and no standard billing system. The design of this teleworking service involves the integration of many existing services like e-mail, messaging, video conferencing, shared whiteboard and database access. Other requirements are for service providers interworking for service and resource usage, security, and QoS specification. Hence, we explore the emerging open service concept to create this integrated teleworking service that can be made available for subscription by corporate bodies and individuals. Service federation is the interaction between teleworkers across service provider domains. It is achieved via the interworking of providersā€™ services, and is an essential aspect of teleworking. We have realised a service federation in a secure and seamless manner in the OSA / Parlay environment via the use of the OSA / Parlay framework. We looked at the use of a framework federation for the actual implementation of service federation. This framework federation is an interworking of frameworks based on an agreed-upon federation contract between them. New framework interfaces were introduced to facilitate this proposed solution, as the OSA / Parlay specifications do not yet support this approach. Service composition is the creation of a new service instance by composing one or more other services. We implemented this via the use of framework and trader federation. The trader federation was used to locate services or users in different ASP domains. A high level design of the teleworking service was done with federation explored for actual implementation. The Common Object Request Broker Architecture (CORBA) trading service was used to prove the concept. The RM-ODP methodology is followed in this teleworking service design. The OSA / Parlay terminal capability, generic call control, multiparty and location and Service Capability Features (SCF) were used for implementing in the CORBA Distributed Processing Environment (DPE)

    Integration of Internet and Telecommunications- An Architecture for Hybrid Services

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    In this article, we propose an architecture for hybrid services, i.e., services that span many network technologies, such as the Public Switched Telephone Network (PSTN), cellular networks and networks based on the Internet Protocol (IP). These services will play an important role in the future because they leverage on the existing infrastructures, rather than requiring new and sophisticated mechanisms to be deployed. We explore a few issues related to hybrid services and propose a platform, as well as a set of components, to facilitate their creation and deployment. The existing infrastructure is only required to generate specific events when requests for hybrid services are detected. We present the design of a service layer, based on Java, that handles the treatment of these special requests. Our service layer is provided with a set of generic components realized according to the JavaBeans model. We illustrate the strength of our architecture by discussing two hybrid-service examples: a calendar service and a call forwarding service
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