4,745 research outputs found

    On The Impact of Internet Naming Evolution: Deployment, Performance, and Security Implications

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    As one of the most critical components of the Internet, the Domain Name System (DNS) provides naming services for Internet users, who rely on DNS to perform the translation between the domain names and network entities before establishing an In- ternet connection. In this dissertation, we present our studies on different aspects of the naming infrastructure in today’s Internet, including DNS itself and the network services based on the naming infrastructure such as Content Delivery Networks (CDNs). We first characterize the evolution and features of the DNS resolution in web ser- vices under the emergence of third-party hosting services and cloud platforms. at the bottom level of the DNS hierarchy, the authoritative DNS servers (ADNSes) maintain the actual mapping records and answer the DNS queries. The increasing use of upstream ADNS services (i.e., third-party ADNS-hosting services) and Infrastructure-as-a-Service (IaaS) clouds facilitates the deployment of web services, and has been fostering the evo- lution of the deployment of ADNS servers. to shed light on this trend, we conduct a large-scale measurement to investigate the ADNS deployment patterns of modern web services and examine the characteristics of different deployment styles, such as perfor- mance, life-cycle of servers, and availability. Furthermore, we specifically focus on the DNS deployment for subdomains hosted in IaaS clouds. Then, we examine a pervasive misuse of DNS names and explore a straightforward solution to mitigate the performance penalty in DNS cache. DNS cache plays a critical role in domain name resolution, providing (1) high scalability at Root and Top-level- domain nameservers with reduced workloads and (2) low response latency to clients when the resource records of the queried domains are cached. However, the pervasive misuses of domain names, e.g., the domain names of “one-time-use” pattern, have negative impact on the effectiveness of DNS caching as the cache has been filled with those entries that are highly unlikely to be retrieved. By leveraging the domain name based features that are explicitly available from a domain name itself, we propose simple policies for improving DNS cache performance and validate their efficacy using real traces. Finally, we investigate the security implications of a fundamental vulnerability in DNS- based CDNs. The success of CDNs relies on the mapping system that leverages the dynamically generated DNS records to distribute a client’s request to a proximal server for achieving optimal content delivery. However, the mapping system is vulnerable to malicious hijacks, as it is very difficult to provide pre-computed DNSSEC signatures for dynamically generated records in CDNs. We illustrate that an adversary can deliberately tamper with the resolvers to hijack CDN’s redirection by injecting crafted but legitimate mappings between end-users and edge servers, while remaining undetectable by exist- ing security practices, which can cause serious threats that nullify the benefits offered by CDNs, such as proximal access, load balancing, and DoS protection. We further demonstrate that DNSSEC is ineffective to address this problem, even with the newly adopted ECDSA that is capable of achieving live signing for dynamically generated DNS records. We then discuss countermeasures against this redirection hijacking

    Algorithms for advance bandwidth reservation in media production networks

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    Media production generally requires many geographically distributed actors (e.g., production houses, broadcasters, advertisers) to exchange huge amounts of raw video and audio data. Traditional distribution techniques, such as dedicated point-to-point optical links, are highly inefficient in terms of installation time and cost. To improve efficiency, shared media production networks that connect all involved actors over a large geographical area, are currently being deployed. The traffic in such networks is often predictable, as the timing and bandwidth requirements of data transfers are generally known hours or even days in advance. As such, the use of advance bandwidth reservation (AR) can greatly increase resource utilization and cost efficiency. In this paper, we propose an Integer Linear Programming formulation of the bandwidth scheduling problem, which takes into account the specific characteristics of media production networks, is presented. Two novel optimization algorithms based on this model are thoroughly evaluated and compared by means of in-depth simulation results

    A Scalable Cluster-based Infrastructure for Edge-computing Services

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    In this paper we present a scalable and dynamic intermediary infrastruc- ture, SEcS (acronym of BScalable Edge computing Services’’), for developing and deploying advanced Edge computing services, by using a cluster of heterogeneous machines. Our goal is to address the challenges of the next-generation Internet services: scalability, high availability, fault-tolerance and robustness, as well as programmability and quick prototyping. The system is written in Java and is based on IBM’s Web Based Intermediaries (WBI) [71] developed at IBM Almaden Research Center

    The impact of User-Browser Interaction on web performance

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    © ACM 2013. This is the author's version of the work. It is posted here for your personal use. Not for redistribution. The definitive Version of Record was published in ACM, In Proceedings of the 28th Annual ACM Symposium on Applied Computing (pp. 695-702). http://dx.doi.org/10.1145/2480362.2480497The user interaction with the current web contents is a major concern when defining web workloads in order to precisely estimate system performance. However, the intrinsic diffi- culty to represent this behavior in a workload model leads many research works to still use workloads non representative of the current web navigations. In contrast, in previous works we demonstrated that the use of an accurate workload model that considers user’s dynamism when navigating the web clearly affects system performance metrics. In this paper we analyze, for the first time, the effect of considering the User-Browser Interaction (UBI) as a part of user’s dynamic behavior on web workload characterization in performance studies. To this end, we evaluate a typical e-commerce scenario and compare the obtained results for different UBI behaviors, such as the use of the back button and parallel browsing originated by using browser tabs or opening new windows when surfing a website.This work has been partially supported by the Spanish Ministry of Science and Innovation under grant TIN-2009-08201.Peña Ortiz, R.; Gil Salinas, JA.; Sahuquillo Borrás, J.; Pont Sanjuan, A. (2013). The impact of User-Browser Interaction on web performance. ACM. https://doi.org/10.1145/2480362.2480497

    Designing Distributed, Component-Based Systems for Industrial Robotic Applications

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    none3noneM. Amoretti; S. Caselli; M. ReggianiM., Amoretti; S., Caselli; Reggiani, Monic

    Ad-hoc Stream Adaptive Protocol

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    With the growing market of smart-phones, sophisticated applications that do extensive computation are common on mobile platform; and with consumers’ high expectation of technologies to stay connected on the go, academic researchers and industries have been making efforts to find ways to stream multimedia contents to mobile devices. However, the restricted wireless channel bandwidth, unstable nature of wireless channels, and unpredictable nature of mobility, has been the major road block for wireless streaming advance forward. In this paper, various recent studies on mobility and P2P system proposal are explained and analyzed, and propose a new design based on existing P2P systems, aimed to solve the wireless and mobility issues

    Back-Office Web Traffic on The Internet

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    Although traffic between Web servers and Web browsers is readily apparent to many knowledgeable end users, fewer are aware of the extent of server-to-server Web traffic carried over the public Internet. We refer to the former class of traffic as front-office Internet Web traffic and the latter as back-office Internet Web traffic (or just front-office and back-office traffic, for short). Back-office traffic, which may or may not be triggered by end-user activity, is essential for today's Web as it supports a number of popular but complex Web services including large-scale content delivery, social networking, indexing, searching, advertising, and proxy services. This paper takes a first look at back-office traffic, measuring it from various vantage points, including from within ISPs, IXPs, and CDNs. We describe techniques for identifying back-office traffic based on the roles that this traffic plays in the Web ecosystem. Our measurements show that back-office traffic accounts for a significant fraction not only of core Internet traffic, but also of Web transactions in the terms of requests and responses. Finally, we discuss the implications and opportunities that the presence of back-office traffic presents for the evolution of the Internet ecosystem

    A two-stage framework for designing visual analytics systems to augment organizational analytical processes

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    A perennially interesting research topic in the field of visual analytics is how to effectively develop systems that support organizational knowledge worker’s decision-making and reasoning processes. The primary objective of a visual analytic system is to facilitate analytical reasoning and discovery of insights through interactive visual interfaces. It also enables the transfer of capability and expertise from where it resides to where it is needed–across individuals, and organizations as necessary. The problem is, however, most domain analytical practices generally vary from organizations to organizations. This leads to the diversified design of visual analytics systems in incorporating domain analytical processes, making it difficult to generalize the success from one domain to another. Exacerbating this problem is the dearth of general models of analytical workflows available to enable such timely and effective designs. To alleviate these problems, this dissertation presents a two-stage framework for informing the design of a visual analytics system. This two-stage design framework builds upon and extends current practices pertaining to analytical workflow and focuses, in particular, on investigating its effect on the design of visual analytics systems for organizational environments. It aims to empower organizations with more systematic and purposeful information analyses through modeling the domain users’ reasoning processes. The first stage in this framework is an Observation and Designing stage, in which a visual analytic system is designed and implemented to abstract and encapsulate general organizational analytical processes, through extensive collaboration with domain users. The second stage is the User-centric Refinement stage, which aims at interactively enriching and refining the already encapsulated domain analysis process based on understanding user’s intentions through analyzing their task behavior. To implement this framework in the process of designing a visual analytics system, this dissertation proposes four general design recommendations that, when followed, empower such systems to bring the users closer to the center of their analytical processes. This dissertation makes three primary contributions: first, it presents a general characterization of the analytical workflow in organizational environments. This characterization fills in the blank of the current lack of such an analytical model and further represents a set of domain analytical tasks that are commonly applicable to various organizations. Secondly, this dissertation describes a two-stage framework for facilitating the domain users’ workflows through integrating their analytical models into interactive visual analytics systems. Finally, this dissertation presents recommendations and suggestions on enriching and refining domain analysis through capturing and analyzing knowledge workers’ analysis processes. To exemplify the generalizability of these design recommendations, this dissertation presents three visual analytics systems that are developed following the proposed recommendations, including Taste for Xerox Corporation, OpsVis for Microsoft, and IRSV for the U.S. Department of Transportation. All of these systems are deployed to domain knowledge workers and are adopted for their analytical practices. Extensive empirical evaluations are further conducted to demonstrate efficacy of these systems in facilitating domain analytical processes
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