86,196 research outputs found

    ADAPTIVE ROUTING BASED ON DELAY TRUSTED ROUTING IN ADHOC NETWORK

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    Existing network hardware is constantly being improved and new communication technology continues to be developed. Together with the trend that computing hardware becomes smaller and portable, this network technology progress has led to dynamic networks. Next generation wireless networks are characterized as heterogeneous networks, particularly in terms of its underlying technology. One of the challenges of these heterogeneous networks is to manage handoff. Mobile IP is chosen for managing the handoff to accommodate the all-IP vision of the future interconnected networks. However, the handoff management of the mobile IP is mainly for data services where delay is not of a major concern. Therefore, it would be considerable challenge to achieve low latency handoff for real-time services. In this paper, we propose a multicasting scheme for delay-sensitive applications

    Bandwidth management and quality of service

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    With the advent of bandwidth-hungry video and audio applications, demand for bandwidth is expected to exceed supply. Users will require more bandwidth and, as always, there are likely to be more users. As the Internet user base becomes more diverse, there is an increasing perception that Internet Service Providers (ISPs) should be able to differentiate between users, so that the specific needs of different types of users can be met. Differentiated services is seen as a possible solution to the bandwidth problem. Currently, however, the technology used on the Internet differentiates neither between users, nor between applications. The thesis focuses on current and anticipated bandwidth shortages on the Internet, and on the lack of a differentiated service. The aim is to identify methods of managing bandwidth and to investigate how these bandwidth management methods can be used to provide a differentiated service. The scope of the study is limited to networks using both Ethernet technology and the Internet Protocol (IP). Tile study is significant because it addresses current problems confronted by network managers. The key terms, Quality of Service (QoS) and bandwidth management, are defined. “QoS” is equated to a differentiating system. Bandwidth management is defined as any method of controlling and allocating bandwidth. Installing more capacity is taken to be a method of bandwidth management. The review of literature concentrates on Ethernet/IP networks. It begins with a detailed examination of definitions and interpretations of the term Quality of Service and shows how the meaning changed over the last decade. The review then examines congestion control, including a survey of queuing methods. Priority queuing implemented in hardware is examined in detail, followed by a review of the ReSource reserVation Protocol (RSVP) and a new version of IP (lPv6). Finally, the new standards IEEE 802.1p and IEEE 802.1Q are outlined, and parts of ISO/IEC 15802-3 are analysed. The Integrated Services Architecture (ISA), Differentiated Services (DiffServ) and MultiProtocol Label Switching (MPLS) are seen as providing a theoretical framework for QoS development. The Open Systems Interconnection Reference Model (OSI model) is chosen as the preferred framework for investigating bandwidth management because it is more comprehensive than the alternative US Department of Defence Model (DoD model). A case study of the Edith Cowan University (ECU) data network illustrates current practice in network management. It provides concrete examples of some of the problems, methods and solutions identified in the literary review. Bandwidth management methods are identified and categorised based on the OSI layers in which they operate. Suggestions are given as to how some of these bandwidth management methods are, or can be used within current QoS architectures. The experimental work consists of two series of tests on small, experimental LANs. The tests are aimed at evaluating the effectiveness of IEEE 802.1 p prioritisation. The results suggest that in small Local Area Networks (LANs) prioritisation provides no benefit when Ethernet switches are lightly loaded

    The development of metrica

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    Examining performance data over time can help operators identify underlying trends that would go unnoticed if the data was merely looked at in real time, then discarded. Network performance reporting management can lead to a more proactive style of network management. Metrica/NPR is a Network Performance Reporting application that provides network operators an integrated view of the performance of telecommunications networks for various technology including wireless, wireline and Internet Protocol (IP). Metrica/NPR helps operators improve their understanding of network behavior by managing, analyzing and reporting, performance statistics generated by the network. Metrica/NPR 3.3 is the latest release of Metrica/NPR product line produced by ADC in order to adopt the challenge of a continuously changing network environment. It is a significant release, which is for the first time being developed from ADC research and development (R&D) center in Kuala Lumpur. ADC Software Systems is an ISO9001:2000 certified company since June 1998 for its management system in product development and deployment. Quality management system, now called as business management system (BMS), is the primary process reference in product development. The development of Metrica/NPR 3.3 explores the internal part of ADC development process involved in producing a great software product, focusing on coding and testing, based on BMS. Besides the requirement of high set of programming technique and deep exploration on different operating system environment, this technical report explains the details aspect of the software development activities such as coding, testing, project management and configuration management

    Deliverable JRA1.1: Evaluation of current network control and management planes for multi-domain network infrastructure

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    This deliverable includes a compilation and evaluation of available control and management architectures and protocols applicable to a multilayer infrastructure in a multi-domain Virtual Network environment.The scope of this deliverable is mainly focused on the virtualisation of the resources within a network and at processing nodes. The virtualization of the FEDERICA infrastructure allows the provisioning of its available resources to users by means of FEDERICA slices. A slice is seen by the user as a real physical network under his/her domain, however it maps to a logical partition (a virtual instance) of the physical FEDERICA resources. A slice is built to exhibit to the highest degree all the principles applicable to a physical network (isolation, reproducibility, manageability, ...). Currently, there are no standard definitions available for network virtualization or its associated architectures. Therefore, this deliverable proposes the Virtual Network layer architecture and evaluates a set of Management- and Control Planes that can be used for the partitioning and virtualization of the FEDERICA network resources. This evaluation has been performed taking into account an initial set of FEDERICA requirements; a possible extension of the selected tools will be evaluated in future deliverables. The studies described in this deliverable define the virtual architecture of the FEDERICA infrastructure. During this activity, the need has been recognised to establish a new set of basic definitions (taxonomy) for the building blocks that compose the so-called slice, i.e. the virtual network instantiation (which is virtual with regard to the abstracted view made of the building blocks of the FEDERICA infrastructure) and its architectural plane representation. These definitions will be established as a common nomenclature for the FEDERICA project. Other important aspects when defining a new architecture are the user requirements. It is crucial that the resulting architecture fits the demands that users may have. Since this deliverable has been produced at the same time as the contact process with users, made by the project activities related to the Use Case definitions, JRA1 has proposed a set of basic Use Cases to be considered as starting point for its internal studies. When researchers want to experiment with their developments, they need not only network resources on their slices, but also a slice of the processing resources. These processing slice resources are understood as virtual machine instances that users can use to make them behave as software routers or end nodes, on which to download the software protocols or applications they have produced and want to assess in a realistic environment. Hence, this deliverable also studies the APIs of several virtual machine management software products in order to identify which best suits FEDERICA’s needs.Postprint (published version

    Appropriation of value in Biomedical research outcome at Public Research Organisations

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    Transactions on biomedical research outcomes bring into play strategies that are determined by leveraging resources into quasi-markets and on options based on expectations. To govern such transactions, the choice of appropriate governance structures and the governance of interaction are all too often in remittance of risk and uncertainty. Organisation and communities are prompted by issues concerning intellectual property (IP) to underwrite information, which is inherently fraught with difficulties of discerning ownership and quantifying qualitative business variables. Against that backdrop, we enquire on the mechanisms underpinning value dissipation and value appropriation of biomedical research outcomes to make proposition on the organisational antecedence to innovation. It is a preamble study with the view to developing a meso-level framework to describe mechanisms of value appropriation of upstream biomedical (non-invasive) research at Public Research Organisation. Its underpinning is largely based on the availability appropriability regimes and viability of organizational governance decisions and how the choice of organizational governance form affects both the creation and appropriation of economic value

    Requirements of a middleware for managing a large, heterogeneous programmable network

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    Programmable networking is an increasingly popular area of research in both industry and academia. Although most programmable network research projects seem to focus on the router architecture rather than on issues relating to the management of programmable networks, there are numerous research groups that have incorporated management middleware into the programmable network router software. However, none seem to be concerned with the effective management of a large heterogeneous programmable network. The requirements of such a middleware are outlined in this paper. There are a number of fundamental middleware principles that are addressed in this paper; these include management paradigms, configuration delivery, scalability and transactions. Security, fault tolerance and usability are also examined—although these are not essential parts of the middleware, they must be addressed if the programmable network management middleware is to be accepted by industry and adopted by other research projects
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