194 research outputs found

    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

    How to accelerate your internet : a practical guide to bandwidth management and optimisation using open source software

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    xiii, 298 p. : ill. ; 24 cm.Libro ElectrĂłnicoAccess to sufficient Internet bandwidth enables worldwide electronic collaboration, access to informational resources, rapid and effective communication, and grants membership to a global community. Therefore, bandwidth is probably the single most critical resource at the disposal of a modern organisation. The goal of this book is to provide practical information on how to gain the largest possible benefit from your connection to the Internet. By applying the monitoring and optimisation techniques discussed here, the effectiveness of your network can be significantly improved

    Performance analysis of a database caching system in a grid environment

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    Tese de mestrado. Engenharia Informática. Faculdade de Engenharia. Universidade do Porto. 200

    Building high-performance web-caching servers

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    Enhancing Video Streaming Quality of DASH over Cloud/Edge Integrated Networks

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    With the advancement of mobile technologies and the popularity of mobile devices, mobile video streaming applications/services have increased considerably in recent years. Dynamic Adaptive Streaming over HTTP (DASH) or MPEG-DASH is one of the most widely used video streaming techniques over the Internet. It adapts video sending bit rate according to available network resources, however, in case of low bandwidth, DASH performs poorly, which will cause video quality degradation and video stalling. Mobile Edge Computing (MEC) or Multi-access Edge Computing, in connection with the backend cloud has been used to reduce latency and overcome some of the video quality degradation problems for mobile video streaming services. However, an end user might be suffering from video quality drop downs when s/he moves out from the coverage of one node to another or when the mobile network condition goes down. To tackle the degradation problems and assure enhanced video streaming quality, a novel follow-me Edge Node Prefetching (ENP) scheme was proposed and developed in the project, by prefetching video segments in advance in the upcoming node used by the end-user. A test bed was set up consisting of a backend cloud (OpenStack), two edge nodes (LXD Containers) and one mobile device, the ENP algorithm was implemented on the cloud server and client sides. Experiments were carried out for the DASH streaming service based on Dash.js from the DASH Industry Forum. Preliminary results show that the ENP scheme can maintain higher video quality and less service migration time when moving from one mobile node to another, when compared to existing approaches, i.e. live migration in Follow-me-Edge and the C-up schemes. The proposed scheme could be useful in smart city applications or providing seamless mobile video streaming services in Cloud/Edge integrated networks.Ibrahim Mohammedamee

    Client-Side Page Element Web-Caching

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    When a user explores different web pages in a given website, the website typically sends the entire requested page even if only a portion of the page was different to the current page. That is, two pages on a given website might share elements on the page like search bar, left bar, navigation controls, advertisements, etc., but this information is retransmitted. Most of the users spent their time on the front-end while downloading all the components in the page. Nowadays, server-side caching of page elements is often done using tools like memcached. The aim of my project is to explore element web page caching on the client-side. That is, our goal is to develop a system that caches the most common html parts of web pages in the website and reuses them in the further web pages reducing the transmission data. This effect probably is currently attainable using frames or object tags; however, the actual UI meaning of these tags is different than one integrated HTML file and so could cause usability issues, therefore, we want to explore solutions which are transparent to the end user -- the solution must behave just like a single fixed web page. In order to explore the advantage of having client-side caching and determine the effect on the response time, we made our server set-up as realistic as possible. So Squid, a front-end load balance, was used when we tested our client-side caching

    Comparison of Different Caching Techniques for High-Performance Web Map Services

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    The demand for digital maps on the Internet has increased considerably in the last few years. Therefore the performance of Web Mapping Services is becoming more and more important. This article introduces different caching techniques for high performance transfer of data using standardized Open Geospatial Consortium (OGC) Web Map Services (WMS). It describes and examines different caching mechanisms based on tile caching, reverse proxy caching and web application acceleration. Furthermore it demonstrates benefits, problems and how data needs to be modified for different caching techniques. The article outlines the advantages of WMS caching systems and investigates the behaviour of these systems with an increasing number of concurrent requests using benchmark tests. This includes the examination of applicability of the INSPIRE service level agreement for view services

    Network-based IP flow mobility support in 3GPPs evolved packet core

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    Includes bibliographical references.Mobile data traffic in cellular networks has increased tremendously in the last few years. Due to the costs associated with licensed spectrum, Mobile Network Operators (MNOs) are battling to manage these increased traffic growths. Offloading mobile data traffic to alternative low cost access networks like Wi-Fi has been proposed as a candidate solution to enable MNOs to alleviate congestion from the cellular networks. This dissertation investigates an offloading technique called IP flow mobility within the 3rd Generation Partnership Project (3GPP) all-IP mobile core network, the Evolved Packet Core (EPC). IP flow mobility would enable offloading a subset of the mobile user‟s traffic to an alternative access network while allowing the rest of the end-user‟s traffic to be kept in the cellular access; this way, traffic with stringent quality of service requirements like Voice over Internet Protocol (VoIP) would not experience service disruption or interruption when offloaded. This technique is different from previous offloading techniques where all the end-user‟s traffic is offloaded. IP flow mobility functionality can be realised with either host- or network-based mobility protocols. The recommended IP flow mobility standard of 3GPP is based on the host-based mobility solution, Dual-Stack Mobile IPv6. However, host-based mobility solutions have drawbacks like long handover latencies and produce signaling overhead in the radio access networks, which could be less appealing to MNOs. Network-based mobility solutions, compared to the host-based mobility solutions, have reduced handover latencies with no signaling overhead occurring in the radio access network. Proxy Mobile IPv6 is a networkbased mobility protocol adapted by 3GPP for mobility in the EPC. However, the standardisation of the Proxy Mobile IPv6-based IP flow mobility functionality is still ongoing within 3GPP. A review of related literature and standardisation efforts reveals shortcomings with the Proxy Mobile IPv6 mobility protocol in supporting IP flow mobility. Proxy Mobile IPv6 does not have a mechanism that would ensure session continuity during IP flow handoffs or a mechanism enabling controlling of the forwarding path of a particular IP flow i.e., specifying the access network for the IP flow. The latter mechanism is referred to as IP flow information management and flow-based routing. These mechanisms represent the basis for enabling the IP flow mobility functionality. To address the shortcomings of Proxy Mobile IPv6, this dissertation proposes vi enhancements to the protocol procedures to enable the two mechanisms for IP flow mobility functionality. The proposed enhancements for the session continuity mechanism draw on work in related literature and the proposed enhancements for the IP flow information management and flow-based routing mechanism are based on the concepts used in the Dual- Stack Mobile IPv6 IP flow mobility functionality. Together the two mechanisms allow the end-user to issue requests on what access network a particular IP flow should be routed, and ensure that the IP flows are moved to the particular access network without session discontinuity

    Non-business use of the World Wide Web : A study of selected Western Australian organisations

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    Employees undertake a wide range of activities when they use the World Wide Web in the work place. Some of these activities may leave the modem Internet connected organisation vulnerable to undue or unknown risk, potential productivity losses and expense us a result of misuse or abuse or the Internet provision. Much of the existing literature on this subject points to a purported epidemic of misuse in the workplace. If this practice is so prevalent and widespread, what can modem Internet connected organisations do to identify the abuse and reduce the risks and losses that these abuses represent? To what extent is the World Wide Web used by employees for non-business related activities in organisations and can filtering or organisational policies impact on this activity? This research specifically examines contextually, the level of misuse with respect to the use of the World Wide Web in three selected Western Australian organisations using multiple interpretive case study as the vehicle for the study. The research is significant internationally to all organisations that use Internet in their everyday work. The research has discovered anomalous behaviour on the part of non-business users who have employed a variety of techniques and tactics to mask their activities. Also, organisational management in the cases examined had demonstrated shortfalls in their perception of misuse within their organisations and, the implementation of effective policy
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