Customizing Data-plane Processing in Edge Routers

While OpenFlow enables the customization of the control plane of a router, currently no solutions are available for the customization of the data plane. This paper presents a prototype that offers to third parties (even end-users) the possibility to install their own applications on the data plane of a router, particularly the ones operating at the edge of the network. This paper presents the motivation of the idea, the reason why we use OpenFlow even if it does not seem appropriate for the data plane, the architecture and the implementation of our prototype, and a first characterization of the system running in our la

Retroarc Neogene volcanism at Payenia: A review

The Payenia basaltic province is a typical retroarc association developed along the foothills of the Andes between 33°40 ́S and 38°00'S. It records two main events, an older, mostly Miocene one (26 to 8 Ma) and a younger Pliocene to Holocene one (younger than 5 Ma). It covers an N-S lowland belt named here the central depression. To the North of 36°20'S, the region was described as Los Huarpes depression, a partially deformed sedimentary basin characterized by a 1000 m-thick, undifferentiated Cenozoic sequence. To the south, Upper Cretaceous to Lower Paleogene layers, instead of the undifferentiated Cenozoic deposits, are covered by basalts. The volcanism additionally covers the western side of the San Rafael Block as well as the fold and thrust belt of the Andean foothills. The Payenia province consists of more than 800 monogenetic basaltic cones, and scarce polygenetic volcanos fed by shallow magmatic chambers. Among the latter, the following examples can be mentioned: Miocene Chachahuén volcano (7 to 5 Ma), composed of andesites, rhyodacites and basalts with high-K and amphibole; Pliocene El Nevado volcano, with calc-alkaline, basaltic trachyandesites, trachytes, dacites and rhyolites; and Upper Pleistocene to Holocene Payún Matrú volcano, composed of trachytes, trachyandesites and trachybasalts. The southernmost area of the central depression is covered by the Pleistocene, Auca Mahuida basaltic shield (1.7 to 0.88 Ma), consisting of trachybasalts, basaltic trachyandesites and trachyandesites. This shield is aligned with Tromen and Domuyo volcanos, defining an NW-SE volcanic belt, oblique to the Andes, whose southern tip corresponds to the Cortaderas lineament. Some of the monogenetic cones are of hydromagmatic origin, whereas a few others exhibit small mantle inclusions. The Payenia retroarc province develops to the south of the Pampean flat slab segment, where the heights of the Andes are smaller. This height difference might have been caused by a higher thermal gradient that softened the crust in the steeper subduction segment, while the colder lithosphere in the flat slab segment allowed greater crustal thickening and height. From the tectonic point of view the height difference has been attributed to a smaller orogenic contraction in the southern segment. Holocene volcanism appears exclusively at Payun Matru volcano. The associated thermal anomaly may explain the segmentation of the central depression, separating the Cenozoic Los Huarpes basin in the north and the section without coeval sedimentation in the south. The only surface evidence of this segmentation is the E-W, La Carbonilla fault, running both sides of the Payun Matru volcano. Other authors have explained this thermal anomaly as a process of crustal thinning and stretching associated with hot injection from the asthenosphere.Fil:Llambías, E.J. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Risso, C. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina

NFV service dynamicity with a DevOps approach : demonstrating zero-touch deployment & operations

Next generation network services will be realized by NFV-based microservices to enable greater dynamics in deployment and operations. Here, we present a demonstrator that realizes this concept using the NFV platform built in the EU FP7 project UNIFY. Using the example of an Elastic Router service, we show automated deployment and configuration of service components as well as corresponding monitoring components facilitating automated scaling of the entire service. We also demonstrate automatic execution of troubleshooting and debugging actions. Operations of the service are inspired by DevOps principles, enabling quick detection of operational conditions and fast corrective actions. This demo conveys essential insights on how the life-cycle of an NFV-based network service may be realized in future NFV platforms

An Efficient Data Exchange Algorithm for Chained Network Functions

In-network function chaining often involves the deployment of multiple applications into a single, possibly multi-tenant, middlebox. This approach has gained much interest since new network paradigms, such as Software Defined Networking (SDN) and Network Function Virtualization (NFV), have been proposed to virtualize resources as well as network functions. In this scenario, it is very common to move data (e.g., packets) from an application to another by means of a switching module that is in charge of chaining network functions in the correct order, also ensuring an adequate level of isolation between any two virtualized components. With this purpose in mind, this paper proposes an efficient algorithm to handle the communication between the internal soft-switch and the heterogeneous network functions that are executed on the same server. Our proposal is designed with the aim of dealing with high speed packet processing, hence an extensive performance evaluation is also provided to prove the goodness of our solution in this context

Observation weights unlock bulk RNA-seq tools for zero inflation and single-cell applications

Dropout events in single-cell RNA sequencing (scRNA-seq) cause many transcripts to go undetected and induce an excess of zero read counts, leading to power issues in differential expression (DE) analysis. This has triggered the development of bespoke scRNA-seq DE methods to cope with zero inflation. Recent evaluations, however, have shown that dedicated scRNA-seq tools provide no advantage compared to traditional bulk RNA-seq tools. We introduce a weighting strategy, based on a zero-inflated negative binomial model, that identifies excess zero counts and generates gene-and cell-specific weights to unlock bulk RNA-seq DE pipelines for zero-inflated data, boosting performance for scRNA-seq

Oscillations of a liquid bridge resulting from the coalescence of two droplets

The inertial oscillations of a bridge of liquid maintained between two disks are studied under condition of negligible gravity. Both experimental and theoretical results are reported. In the experiment, the bridge is formed by the coalescence of two droplets so that its static equilibrium shape is either concave or convex depending on its length. After coalescence, the bridge performs weakly damped oscillations until it reaches its equilibrium shape. Four modes of oscillations are extracted from digital processing of images recorded by means of a high-speed camera. Their frequency and damping rate are determined and found to be independent of the initial conditions that fix the amplitudes of each mode. Concurrently, the eigen modes of oscillations of a non-cylindrical bridge have been computed by assuming inviscid flow and small amplitude oscillations. The agreement between theoretical and measured frequencies confirms that the experimental modes correspond to the eigenmodes of the linear inviscid theory. Their characteristics turn out to be significantly different from that of a cylindrical bridge. In particular, the eigenfrequencies scale as root gamma/rho R-m(3), where gamma is the surface tension, rho the liquid density, and R-m the radius at the middle of the bridge, which characterizes the shrunk/swollen character of the mean shape

Fog Computing and Networking: Part 2

The articles in this special section focus on the deployment of fog computing in communication networks

Clarifying fog computing and networking: 10 questions and answers

Fog computing is an end-to-end horizontal architecture that distributes computing, storage, control, and networking functions closer to users along the cloud-to-thing continuum. The word “edge” may carry different meanings. A common usage of the term refers to the edge network as opposed to the core network, with equipment such as edge routers, base stations, and home gateways. In that sense, there are several differences between fog and edge. First, fog is inclusive of cloud, core, metro, edge, clients, and things. The fog architecture will further enable pooling, orchestrating, managing, and securing the resources and functions distributed in the cloud, anywhere along the cloud-to-thing continuum, and on the things to support end-to-end services and applications. Second, fog seeks to realize a seamless continuum of computing services from the cloud to the things rather than treating the network edges as isolated computing platforms. Third, fog envisions a horizontal platform that will support the common fog computing functions for multiple industries and application domains, including but not limited to traditional telco services. Fourth, a dominant part of edge is mobile edge, whereas the fog computing architecture will be flexible enough to work over wireline as well as wireless networks

Fog Computing and Networking: Part 1 [Guest editorial]

The articles in this special section focus on fog computing and networking. Fog rises as cloud descends to be closer to the end users. Building on the foundation of past work in related areas and driven by emerging new applications and capabilities, fog computing and networking is now presenting unique opportunities to university researchers and the industry. These articles consists of overview articles that span much of this growing terrain of fog

Unilateral leg swelling in a newborn

A female neonate was born with asymmetric lower limbs, the right leg appearing enlarged, with thickened, reddish-purple skin and ectasic superficial reticulum (figure 1A,B). Limb pulses were present and symmetrical. The girl's family history and prenatal scans were unremarkable. Laboratory findings were within the normal range, except for a mild thrombocytopenia (90 000/μL), which spontaneously resolved during the next few days. A leg X-ray and the Doppler analysis ruled out the presence of calcifications and venous varices, respectively. Ultrasound showed significant skin thickening, with marked dermal hypertrophy and hyperechogenicity. Magnetic resonance showed circumferential thickening of the derma, with mild hypertrophy of some perforating vessels (figure 2). A biopsy of the right thigh showed capillary malformations on histology. edpract;archdischild-2020-320450v1/BLKF1F1BLK_F1Figure 1(A, B) Hypertrophy of the right lower limb, with large capillary malformation extending to the gluteus and the external genitalia. edpract;archdischild-2020-320450v1/BLKF2F2BLK_F2Figure 2Axial THRIVE magnetic resonance scan of the thighs' proximal third, showing circumferential dermal thickening and inhomogeneity of the right leg's subcutaneous tissue. QUESTIONS: Based on the clinical picture and investigations results, which is the most likely diagnosis?Beckwith-WiedemannCLOVES syndromeKlippel-Trenaunay syndromeKaposiform hemangioendotheliomaHow can the diagnosis be confirmed?CT with PETLymphoscintigraphyGenetic testingNone of the above, the diagnosis is clinicalWhat is the mainstay of management?Conservative with follow-upPharmacotherapySclerotherapySurgeryWhich of the following complications can occur?ScoliosisGlaucomaUrinary and gastrointestinal bleedingAll of the above Answers can be found on page 02