61,149 research outputs found

    No NAT'd User left Behind: Fingerprinting Users behind NAT from NetFlow Records alone

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    It is generally recognized that the traffic generated by an individual connected to a network acts as his biometric signature. Several tools exploit this fact to fingerprint and monitor users. Often, though, these tools assume to access the entire traffic, including IP addresses and payloads. This is not feasible on the grounds that both performance and privacy would be negatively affected. In reality, most ISPs convert user traffic into NetFlow records for a concise representation that does not include, for instance, any payloads. More importantly, large and distributed networks are usually NAT'd, thus a few IP addresses may be associated to thousands of users. We devised a new fingerprinting framework that overcomes these hurdles. Our system is able to analyze a huge amount of network traffic represented as NetFlows, with the intent to track people. It does so by accurately inferring when users are connected to the network and which IP addresses they are using, even though thousands of users are hidden behind NAT. Our prototype implementation was deployed and tested within an existing large metropolitan WiFi network serving about 200,000 users, with an average load of more than 1,000 users simultaneously connected behind 2 NAT'd IP addresses only. Our solution turned out to be very effective, with an accuracy greater than 90%. We also devised new tools and refined existing ones that may be applied to other contexts related to NetFlow analysis

    Innovation, Learning Organizations and Industrial Relations

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    Innovation may be seen as a process of knowledge creation and the speed and direction of knowledge creation reflects the organizational set-up of the firm as well as its investments in R&D and training. Establishing ‘a learning organization’ where horizontal interaction and communication inside and across the borders of the firm is a major factor promoting knowledge creation in the context of a learning economy. An important issue is to what extent direct and indirect participation of employees in shaping the new form of organization is critical for its realization. On the basis of a unique data set covering 2000 Danish private firms it is demonstrated that firms combining several of the organizational traits of the learning organization are much more prone to introduce new products than the others. It is also demonstrated that such firms have involved employees in different forms of direct and indirect participation much more frequently than the rest. As more sectors become exposed to the need to engage in incremental product and service innovation the economic potential of diffusing good practices in terms of organization and participation is growing and needs to be reflected in firm strategies and public policies aiming at promoting innovation and knowledge creation.Innovation, knowledge creation, learning economy

    zCap: a zero configuration adaptive paging and mobility management mechanism

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    Today, cellular networks rely on fixed collections of cells (tracking areas) for user equipment localisation. Locating users within these areas involves broadcast search (paging), which consumes radio bandwidth but reduces the user equipment signalling required for mobility management. Tracking areas are today manually configured, hard to adapt to local mobility and influence the load on several key resources in the network. We propose a decentralised and self-adaptive approach to mobility management based on a probabilistic model of local mobility. By estimating the parameters of this model from observations of user mobility collected online, we obtain a dynamic model from which we construct local neighbourhoods of cells where we are most likely to locate user equipment. We propose to replace the static tracking areas of current systems with neighbourhoods local to each cell. The model is also used to derive a multi-phase paging scheme, where the division of neighbourhood cells into consecutive phases balances response times and paging cost. The complete mechanism requires no manual tracking area configuration and performs localisation efficiently in terms of signalling and response times. Detailed simulations show that significant potential gains in localisation effi- ciency are possible while eliminating manual configuration of mobility management parameters. Variants of the proposal can be implemented within current (LTE) standards

    The impact of broadband in schools

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    The report reviews evidence for the impact of broadband in English schools, exploring; Variations in provision in level of broadband connectivity; Links between the level of broadband activity and nationally accessible performance data; Aspects of broadband connectivity and the school environment that contribute to better outcomes for pupils and teachers; Academic and motivational benefits associated with educational uses of this technology

    Data analytics 2016: proceedings of the fifth international conference on data analytics

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