1,987 research outputs found

    Replacing the Ethernet access mechanism with the real-time access mechanism of Twentenet

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    The way in which a Local Area Network access mechanism (Medium Access Control protocol) designed for a specific type of physical service can be used on top of another type of physical service is discussed using a particular example. In the example, an Ethernet physical layer is used to provide service to the Twentenet real-time access mechanism. Relevant Ethernet and Twentenet concepts are explained, the approach taken is introduced, and problems encountered, along with the actual synthesis of both networks, are described

    Self-management of lambda-connections in optical networks

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    This paper presents a new idea for the management of lambda-connections in optical networks. The idea consists of making multi-service optical switches responsible for automatically detecting IP flows at the packet-level, creating lambda-connections for them, and moving them to the optical-level. In addition to that, they are also in charge of tearing down the connections when no longer needed. This new idea is the result of 1 year of research work at the University of Twente (UT) and it is aimed at resulting in a Ph.D. thesis by the end of 4 years of Ph.D. research

    The Hidden Energy Cost of Web Advertising

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    Advertising is an important source of income for many websites. To get the attention of the unsuspecting (and probably uninterested) visitors, web advertisements (ads) tend to use elaborate animations and graphics. Depending on the specific technology being used, displaying such ads on the visitor's screen may require a vast amount of CPU-power. Since present day desktop-CPUs can easily use 100W or more, ads may consume a substantial amount of energy. Although it is important for environmental reasons to reduce energy consumption, increasing the number of ads seems to be counterproductive.\ud The goal of this paper is to investigate the power consumption of web advertisements. For this purpose we used an energy meter to measure the differences in PC power consumption while browsing the web normally (thus with ads enabled), and while browsing with ads being blocked.\ud To simulate normal web browsing, we created a browser-based tool called AutoBrowse, which periodically opens an URL from a predefined list. To block advertisements, we used the Adblock Plus extension for Mozilla Firefox. To measure also power consumption with other browsers, we used in addition the Apache HTTP server and its mod_proxy module to act as an ad-blocking proxy server.\ud The measurements on several PCs and browsers show that, on average, the additional energy consumption to display web advertisements is 2.5W. To put this number into perspective, we calculated that the total amount of energy used to display web advertisement is equivalent of the total yearly electricity consumption of nearly 2000 households in the Netherlands. It takes 3,6 “average” wind turbines to generate this amount of energy

    Scalable Detection and Isolation of Phishing

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    This paper presents a proposal for scalable detection and isolation of phishing. The main ideas are to move the protection from end users towards the network provider and to employ the novel bad neighborhood concept, in order to detect and isolate both phishing e-mail senders and phishing web servers. In addition, we propose to develop a self-management architecture that enables ISPs to protect their users against phishing attacks, and explain how this architecture could be evaluated. This proposal is the result of half a year of research work at the University of Twente (UT), and it is aimed at a Ph.D. thesis in 2012

    DNS zones revisited

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    Recent research [Pap04b] suggests DNS reliability and performance is not up to the levels it should be due to misconfigurations. This paper checks the configuration of nameserver zones against additional requirements, recommendations and best-practices. It shows that almost one in four domains fails to pass one or more of these checks. During the checks an interesting correlation is established: a higher number of nameservers for a single zone usually decreases reliability and performance instead of increasing both

    Report of the Third Workshop on the Usage of NetFlow/IPFIX in Network Management

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    The Network Management Research Group (NMRG) organized in 2010 the Third Workshop on the Usage of NetFlow/IPFIX in Network Management, as part of the 78th IETF Meeting in Maastricht. Yearly organized since 2007, the workshop is an opportunity for people from both academia and industry to discuss the latest developments of the protocol, possibilities for new applications, and practical experiences. This report summarizes the presentations and the main conclusions of the workshop

    Remote MIB-item look-up service

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    Despite some deficiencies, the Internet management framework is widely deployed and thousands of management information base (MIB) modules have been defined thus far. These modules are used by implementers of agent software, as well as by managers and management applications, to understand the syntax and semantics of the management information that may be exchanged. At the manager's side, MIB modules are usually stored in separate files, which are maintained by the human manager and read by the management application. Since maintenance of this file repository can be cumbersome, management applications are often confronted with incomplete and outdated information. To solve this "meta-management" problem, this paper discusses the design of a remote look-up service for MIB-item definitions. Such a service facilitates the retrieval of missing MIB module definitions, as well as definitions of individual MIB-items. Initially the service may be provided by a single server, but other servers can be added at later stages to improve performance and prevent copyright problems. It is envisaged that vendors of network equipment will also install servers, to distribute their vendor specific MIB. The paper describes how the service, which is provided on a best effort basis, can be accessed by managers/management applications, and how servers inform each other about the MIB modules they support

    Assessing unknown network traffic

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    Recent measurements have shown that a growing fraction of all Internet traffic is unknown: it is unclear which applications are causing the traffic. Therefore we have developed and applied a novel methodology to find out what applications are running on the network. This methodology is based on the notion of Âżinduced trafficÂż: traffic cannot (wide-scale) be on unknown ports, thus, \ud the hypothesis is that such traffic on unknown ports should be preceeded by traffic on known ports between the same peers. We have developed and implemented an algorithm to test this hypothesis. After applying the algorithm in two case studies we, unfortunately, have to conclude that although some improvement is made, there is still a significant fraction of traffic unidentifiable

    «FRIENDLY» COMPLAINING BEHAVIORS: TOWARD A RELATIONAL APPROACH

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    The relational approach is often presented as a strategy to retain customers, but it may also be an appropriate approach to encourage customers to complain, as a review of literature shows. Using information contained in complaints and giving the right answers (distributive, procedural and interactional) to such complaints is essential. Relational marketing may also be used to induce customers (but not all of them) to complain about the attributes of certain products/services. This article focuses on these issues and should stimulate further research in this new field.Relationship Marketing; Complaining Behavior; Friendly Complaints, Justice Theory
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