OSHI - Open Source Hybrid IP/SDN networking (and its emulation on Mininet and on distributed SDN testbeds)

The introduction of SDN in IP backbones requires the coexistence of regular IP forwarding and SDN based forwarding. The former is typically applied to best effort Internet traffic, the latter can be used for different types of advanced services (VPNs, Virtual Leased Lines, Traffic Engineering...). In this paper we first introduce the architecture and the services of an "hybrid" IP/SDN networking scenario. Then we describe the design and implementation of an Open Source Hybrid IP/SDN (OSHI) node. It combines Quagga for OSPF routing and Open vSwitch for OpenFlow based switching on Linux. The availability of tools for experimental validation and performance evaluation of SDN solutions is fundamental for the evolution of SDN. We provide a set of open source tools that allow to facilitate the design of hybrid IP/SDN experimental networks, their deployment on Mininet or on distributed SDN research testbeds and their test. Finally, using the provided tools, we evaluate key performance aspects of the proposed solutions. The OSHI development and test environment is available in a VirtualBox VM image that can be downloaded.Comment: Final version (Last updated August, 2014

Hybrid IP/SDN networking: open implementation and experiment management tools

The introduction of SDN in large-scale IP provider networks is still an open issue and different solutions have been suggested so far. In this paper we propose a hybrid approach that allows the coexistence of traditional IP routing with SDN based forwarding within the same provider domain. The solution is called OSHI - Open Source Hybrid IP/SDN networking as we have fully implemented it combining and extending Open Source software. We discuss the OSHI system architecture and the design and implementation of advanced services like Pseudo Wires and Virtual Switches. In addition, we describe a set of Open Source management tools for the emulation of the proposed solution using either the Mininet emulator or distributed physical testbeds. We refer to this suite of tools as Mantoo (Management tools). Mantoo includes an extensible web-based graphical topology designer, which provides different layered network "views" (e.g. from physical links to service relationships among nodes). The suite can validate an input topology, automatically deploy it over a Mininet emulator or a distributed SDN testbed and allows access to emulated nodes by opening consoles in the web GUI. Mantoo provides also tools to evaluate the performance of the deployed nodes.Comment: Accepted for publication in IEEE Transaction of Network and Service Management - December 2015 http://dx.doi.org/10.1109/TNSM.2015.250762

Prevalence of hypospadias in Italy according to severity, gestational age and birthweight: an epidemiological study

<p>Abstract</p> <p>Background</p> <p>Hypospadias is a congenital displacement of the urethral meatus in male newborns, being either an isolated defect at birth or a sign of sexual development disorders. The aim of this study was to assess the prevalence rate of hypospadias in different Districts of Italy, in order to make a comparison with other countries all over the world.</p> <p>Methods</p> <p>We reviewed all the newborns file records (years 2001–2004) in 15 Italian Hospitals.</p> <p>Results</p> <p>We found an overall hypospadias prevalence rate of 3.066 ± 0.99 per 1000 live births (82.48% mild hypospadias, 17.52% moderate-severe). In newborns Small for Gestational Age (birthweight < 10^thpercentile) of any gestational age the prevalence rate of hypospadias was 6.25 per 1000 live births. Performing multivariate logistic regression analysis for different degrees of hypospadias according to severity, being born SGA remained the only risk factor for moderate-severe hypospadias (p = 0.00898) but not for mild forms (p > 0.1).</p> <p>Conclusion</p> <p>In our sample the prevalence of hypospadias results as high as reported in previous European and American studies (3–4 per 1000 live births). Pathogenesis of isolated hypospadias is multifactorial (genetic, endocrine and environmental factors): however, the prevalence rate of hypospadias is higher in infants born small for gestational age than in newborns with normal birth weight.</p

Voyage [d' Horace Vernet] en Orient

Dedication:Content description: TitleIllustration: (portraits ,varia ,)Pagination: PP2+328PVolumes: 1Format: 22cmText Genre:Prose / JournalIllustration: (πορτραίτα ,άλλα θέματα ,

Una descrizione di Candia del principio del seicento.

Preface: , Gerola, GiuseppeDedication:Pagination: 15PVolumes: 1Edition:ReprintText Genre:Pros