Inter-domain networking innovation on steroids: Empowering IXPs with SDN capabilities

While innovation in inter-domain routing has remained stagnant for over a decade, Internet Exchange Points (IXPs) are consolidating their role as economically advantageous interconnection points for reducing path latencies and exchanging ever increasing amounts of traffic. As such, IXPs appear as a natural place to foster network innovation and assess the benefits of Software-Defined Networking (SDN), a recent technological trend that has already boosted innovation within data-center networks. In this paper, we give a comprehensive overview of use cases for SDN at IXPs, which leverage the superior vantage point of an IXP to introduce advanced features like load-balancing and DDoS mitigation. We discuss the benefits of SDN solutions by analyzing real-world data from one of the largest IXPs. We also leverage insights into IXP operations to not only shape benefits for members but also for operators.This research is (in part) supported by European Union’s Horizon 2020 research and innovation programme under the ENDEAVOUR project (grant agreement 644960).This is the author accepted manuscript. The final version is available from IEEE via https://doi.org/ 10.1109/MCOM.2016.758827

Counting the Solutions of Presburger Equations without Enumerating Them

peer reviewedThe Number Decision Diagram (NDD) has recently been proposed as a powerful representation system for sets of integer vectors. In particular, NDDs can be used for representing the sets of solutions of arbitrary Presburger formulas, or the set of reachable states of some systems using unbounded integer variables. In this paper, we address the problem of counting the number of distinct elements in a set of vectors represented as an NDD. We give an algorithm that is able to perform an exact count without enumerating explicitly the vectors, which makes it capable of handling very large sets. As an auxiliary result, we also develop an efficient projection method that allows to construct efficiently NDDs from quantified formulas, and thus makes it possible to apply our counting technique to sets specified by formulas. Our algorithms have been implemented in the verification tool LASH, and applied successfully to various counting problems.ARC - Actions de recherche concertée

An Algorithm for Deciding BAPA: Boolean Algebra with Presburger Arithmetic

We describe an algorithm for deciding the first-order multisorted theory BAPA, which combines 1) Boolean algebras of sets of uninterpreted elements (BA) and 2) Presburger arithmetic operations (PA). BAPA can express the relationship between integer variables and cardinalities of sets, and supports arbitrary quantification over both sets and integers.Our motivation for BAPA is deciding verification conditions that arise in the static analysis of data structure consistency properties. Data structures often use an integer variable to keep track of the number of elements they store; an invariant of such a data structure is that the value of the integer variable is equal to the number of elements stored in the data structure. When the data structure content is represented by a set, the resulting constraints can be captured in BAPA. BAPA formulas with quantifier alternations arise when annotations contain quantifiers themselves, or when proving simulation relation conditions for refinement and equivalence of program fragments. Furthermore, BAPA constraints can be used to extend the techniques for proving the termination of integer programs to programs that manipulate data structures, and have applications in constraint databases.We give a formal description of a decision procedure for BAPA, which implies the decidability of the satisfiability and validity problems for BAPA. We analyze our algorithm and obtain an elementary upper bound on the running time, thereby giving the first complexity bound for BAPA. Because it works by a reduction to PA, our algorithm yields the decidability of a combination of sets of uninterpreted elements with any decidable extension of PA. Our algorithm can also be used to yield an optimal decision procedure for BA though a reduction to PA with bounded quantifiers.We have implemented our algorithm and used it to discharge verification conditions in the Jahob system for data structure consistency checking of Java programs; our experience with the algorithm is promising

Disability Management

none1noSummary Diversity management manifests in a set of transversal business practices – under the “umbrella” of the corporate social responsibility policies – that affect the corporate culture, the strategy, the financial and control management system, the operational activities, as well as the system of relations with the stakeholders and the company reporting (Angeloni 2013; D’Amato 2009; Metallo et al. 2009; Migliaccio 2016). The growing attention paid by policy makers, businesses, and institutions to diversity management is attributable to the increased complexity of society, characterized by a multiplicity of social, cultural, and individual subjectivities tied to gender, age, ethnic origins, disability, sexual orientation, personality characteristics, cognitive styles, level of education, background, etc. In such a context disability management is conceived as a proactive strategy aimed at identifying and solving the factors that prevent people with any type of disability from accessing work (Geisen and Harder 2011). While diversity management consists in practices that an organization implements to create an inclusive climate and an organizational culture (Oberfield 2014), aimed to allow workers attitudes and capabilities flourish and ensure growth and success of their personal and professional paths, disability management is not only limited to a process or to a set of procedures (O’Brien 2013; Sabharwal 2014), but it represents a professional activity which considers all the relational aspects (personal contacts and interactions) that contribute to the success of disability management. Currently disability strategies are often implemented as a reaction to the problems of a single person or an organization, while empirical studies suggest to consider such problems in advance through appropriate policies and procedures for overcoming and preventing them (Geisen and Harder 2011). Namely, workplace disability management concerns all cases of disability from personal and congenital disabilities tothose acquired during the working period (ranging from accidents to chronic-degenerative diseases). In this sense, disability management is conceived as a proactive strategy oriented to identify and remove all the factors that prevent people, with any type of disability, from accessing to developing a professional path (Bruyére and Filiberto 2013; Rahim et al. 2017). This conception differs from a more restrictive one according to which disability management coincides with the return to work, of disable people who are already working.https://link.springer.com/referencework/10.1007/978-3-030-02006-4 Book Springer Series: CSR, Sustainabiliy, Ethics & Governance. ISSN 2196-7075 ISSN 2196 – 7083 (electronic) E227181 Bibliographic information • DOIhttps://doi.org/10.1007/978-3-030-02006-4 • Copyright Information Springer Nature Switzerland AG 2020 • Publisher NameSpringer, Cham • Online ISBN 978-3-030-02006-4 • eBook PackagesBusiness and ManagementReference Module Humanities and Social SciencesrestrictedDel Baldo, MaraDel Baldo, Mar