10 research outputs found

    An Application-aware SDN Controller for Hybrid Optical-electrical DC Networks

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    The adoption of optical switching technologies in Data Centre Networks (DCNs) offers a solution for high speed traffic and energy efficiency in Data Centre (DC) operational management, enabling an easy scaling of DC infrastructures. Flexible, slotted allocation of optical resources is fundamental to efficiently support the dynamicity of DC traffic. In this context, the NEPHELE project proposes a Time Division Multiple Access approach for optical resource allocation, orchestrated through a Software Defined Networking controller which coordinates the DCN configuration based on real-time cloud application requests

    Reducing the complexity of virtual machine networking

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    Virtualization is an enabling technology that improves scalability, reliability, and flexibility. Virtualized networking is tackled by emulating or paravirtualizing network interface cards. This approach, however, leads to complexities (implementation and management) and has to conform to some limitations imposed by the Ethernet standard. RINA turns the current approach to virtualized networking on its head: instead of emulating networks to perform inter-process communication on a single processing system, it sees networking as an extension to local inter-process communication. In this article, we show how RINA can leverage a paravirtualization approach to achieve a more manageable solution for virtualized networking. We also present experimental results performed on IRATI, the reference open source implementation of RINA, which shows the potential performance that can be achieved by deploying our solution

    Milk composition, fatty acids profile and fat globule size of Bottlenose Dolphin (Tursiops truncatus, Montagu 1821) milk at early lactation

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    RResearch data on milk composition in cetaceans are scattered and fragmentary. This paper analyses the gross and mineral composition, the fatty acids profile and the fat globule size of bottlenose dolphin (Tursiops truncatus) colostrum and milk at early lactation. The milk samplings were carried out on three lactating female of bottlenose dolphins at the 1st, 4-5 and 20- 42 day post partum. High percentages of dry matter (51.88%), fat (26.08%) and protein (13.83%) were found in the colostrum on the first day, while there was a tendency for these components to decrease in the milk. The average diameter the milk fat globule (7.07 μm) of this species was assessed for the first time. The milk was rich in unsaturated fatty acids, which were more than twice compared to the saturated fatty acids (unsaturated / saturated ratio = 2.6). The main fatty acids of dolphin milk were C16: 0, C16:1 n-7, C18: 1n-9, C20: 1 n-11 C20: 5 and C22:6n-3. Several FA tended to increase from colostrum to milk: C12: 0 doubled, C20: 1 n-7 and C22:1 n-11 tripled, C20: 1 n-9 quintupled in later milk samples. Differently, other FA tended to decrease: C18: 3 n-3 was approximately 4 times lower and C24: 0 and C24: 1 halved in milk compared to colostrum. In conclusion, this paper contributes to the knowledge of the nutritional value of milk from bottlenose dolphins maintained under human care. Higher content of nutritional components such as fat and protein was found in the first day colostrum compared to milk. Moreover, the findings of this study highlight abundance of unsaturated fatty acids and large sized milk fat globules in dolphin milk

    Reducing Complexity of Virtual Machine Networking

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    Virtualization is an enabling technology that improves scalability, reliability, and flexibility. Virtualized networking is tackled by emulating or paravirtualizing network interface cards. This approach, however, leads to complexities (implementation and management) and has to conform to some limitations imposed by the Ethernet standard. RINA turns the current approach to virtualized networking on its head: instead of emulating networks to perform inter-process communication on a single processing system, it sees networking as an extension to local inter-process communication. In this article, we show how RINA can leverage a paravirtualization approach to achieve a more manageable solution for virtualized networking. We also present experimental results performed on IRATI, the reference open source implementation of RINA, which shows the potential performance that can be achieved by deploying our solution

    Orchestrating virtual slices in data centre infrastructures with optical DCN

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    The emergence of new paradigms and services is pushing the limits of nowadays cloud infrastructures. It is a fact that current solutions lack in the flexibility and configurability to adapt to heterogeneous requirements coming from the applications/services to be supported over them. This results most of the time in severe underutilization of the underlying physical substrate. In light of this, newer approaches on resource provisioning and infrastructure management are needed. The Infrastructure as a Service (IaaS) paradigm is proposed as a solution to overcome these limitations. Thanks to IaaS, the physical infrastructure is partitioned onto virtual slices, encompassing heterogeneous resources (e.g. network, computing). Such a concept is expected to be harnessed by future data center (DC) infrastructures in order to cope efficiently with multi-tenancy as well as heterogeneous application requirements. However, current DC networks (DCNs) impose sever limitations onto traffic handling to fully exploit this vision. In light of this, optical technologies are seen as prime candidates for realizing the high performance network fabrics that future DC architectures will need. Under such an umbrella, it becomes primordial to develop specific provisioning solutions that account for the particularities of the optical medium, while providing the means to efficiently slice the DC infrastructure. With all of these in mind, in this article we present a solution for orchestrating and controlling virtual slices in a DC scenario with optical intra-DCN, with the scope of optimizing the underlying physical infrastructure utilization. The benefits of the presented solution are demonstrated against legacy architectures through exhaustive experiments and simulations.Peer ReviewedPostprint (author's final draft

    A survey of cloud services and potential applications of social awareness

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    The variety of emerging cloud services and applications manifests in a multitude of network and hardware requirements, but also in different service and traffic characteristics. Due to the popularity of clouds, a set of issues emerges for the different stakeholders involved in providing and delivering cloud services to the end user. Not only pure network layer optimization, but especially the new field of socially-aware traffic management seems promising to overcome these issues. In this paper, the applicability of social awareness to different types of cloud services is discussed. For that purpose, cloud applications are classified according to relevant technical and non-technical characteristics. Based on this novel classification scheme, the benefits and challenges of social awareness are discussed and examples for the optimization of cloud services are given

    The bottlenose dolphin (Tursiops truncatus) faecal microbiota

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    Cetaceans have evolved from herbivorous terrestrial artiodactyls closely related to ruminants and hippopotamuses. Delphinidae, a family included in this order, represent an extreme and successful re-adaptation of mammalian physiology to the marine habitat and piscivorous diet. The anatomical aspects of Delphinidae success are well understood, whereas some physiological aspects of their environmental fitness are less defined, such as the gut microbiota composition and its adaptation to their dietary niche. Here, we explored the faecal microbiota structure of nine adult bottlenose dolphins (Tursiops truncatus) and one breast-fed calf living in a controlled environment. According to our findings, dolphins possess a unique microbiota profile within the Mammalia class, highly resembling that of carnivorous marine fishes. The breast-fed calf showed a distinctive compositional structure of the gut microbial ecosystem, which partially overlaps with the mother's milk microbiota. Taken together, our data indicate that in dolphins the adaptation to the marine niche and piscivorous diet involved the convergence of their gut microbiota structure with that of marine fishes, overcoming the gut microbiota phylogenetic inertia previously described in terrestrial mammalians

    Orchestrating virtual slices in data centre infrastructures with optical DCN

    No full text
    The emergence of new paradigms and services is pushing the limits of nowadays cloud infrastructures. It is a fact that current solutions lack in the flexibility and configurability to adapt to heterogeneous requirements coming from the applications/services to be supported over them. This results most of the time in severe underutilization of the underlying physical substrate. In light of this, newer approaches on resource provisioning and infrastructure management are needed. The Infrastructure as a Service (IaaS) paradigm is proposed as a solution to overcome these limitations. Thanks to IaaS, the physical infrastructure is partitioned onto virtual slices, encompassing heterogeneous resources (e.g. network, computing). Such a concept is expected to be harnessed by future data center (DC) infrastructures in order to cope efficiently with multi-tenancy as well as heterogeneous application requirements. However, current DC networks (DCNs) impose sever limitations onto traffic handling to fully exploit this vision. In light of this, optical technologies are seen as prime candidates for realizing the high performance network fabrics that future DC architectures will need. Under such an umbrella, it becomes primordial to develop specific provisioning solutions that account for the particularities of the optical medium, while providing the means to efficiently slice the DC infrastructure. With all of these in mind, in this article we present a solution for orchestrating and controlling virtual slices in a DC scenario with optical intra-DCN, with the scope of optimizing the underlying physical infrastructure utilization. The benefits of the presented solution are demonstrated against legacy architectures through exhaustive experiments and simulations.Peer Reviewe
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