1,505 research outputs found

    Deliverable JRA1.1: Evaluation of current network control and management planes for multi-domain network infrastructure

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    This deliverable includes a compilation and evaluation of available control and management architectures and protocols applicable to a multilayer infrastructure in a multi-domain Virtual Network environment.The scope of this deliverable is mainly focused on the virtualisation of the resources within a network and at processing nodes. The virtualization of the FEDERICA infrastructure allows the provisioning of its available resources to users by means of FEDERICA slices. A slice is seen by the user as a real physical network under his/her domain, however it maps to a logical partition (a virtual instance) of the physical FEDERICA resources. A slice is built to exhibit to the highest degree all the principles applicable to a physical network (isolation, reproducibility, manageability, ...). Currently, there are no standard definitions available for network virtualization or its associated architectures. Therefore, this deliverable proposes the Virtual Network layer architecture and evaluates a set of Management- and Control Planes that can be used for the partitioning and virtualization of the FEDERICA network resources. This evaluation has been performed taking into account an initial set of FEDERICA requirements; a possible extension of the selected tools will be evaluated in future deliverables. The studies described in this deliverable define the virtual architecture of the FEDERICA infrastructure. During this activity, the need has been recognised to establish a new set of basic definitions (taxonomy) for the building blocks that compose the so-called slice, i.e. the virtual network instantiation (which is virtual with regard to the abstracted view made of the building blocks of the FEDERICA infrastructure) and its architectural plane representation. These definitions will be established as a common nomenclature for the FEDERICA project. Other important aspects when defining a new architecture are the user requirements. It is crucial that the resulting architecture fits the demands that users may have. Since this deliverable has been produced at the same time as the contact process with users, made by the project activities related to the Use Case definitions, JRA1 has proposed a set of basic Use Cases to be considered as starting point for its internal studies. When researchers want to experiment with their developments, they need not only network resources on their slices, but also a slice of the processing resources. These processing slice resources are understood as virtual machine instances that users can use to make them behave as software routers or end nodes, on which to download the software protocols or applications they have produced and want to assess in a realistic environment. Hence, this deliverable also studies the APIs of several virtual machine management software products in order to identify which best suits FEDERICA’s needs.Postprint (published version

    Train-scheduling optimization model for railway networks with multiplatform stations

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    This paper focuses on optimizing the schedule of trains on railway networks composed of busy complex stations. A mathematical formulation of this problem is provided as a Mixed Integer Linear Program (MILP). However, the creation of an optimal new timetable is an NP-hard problem; therefore, the MILP can be solved for easy cases, computation time being impractical for more complex examples. In these cases, a heuristic approach is provided that makes use of genetic algorithms to find a good solution jointly with heuristic techniques to generate an initial population. The algorithm was applied to a number of problem instances producing feasible, though not optimal, solutions in several seconds on a laptop, and compared to other proposals. Some improvements are suggested to obtain better results and further improve computation time. Rail transport is recognized as a sustainable and energy-efficient means of transport. Moreover, each freight train can take a large number of trucks off the roads, making them safer. Studies in this field can help to make railways more attractive to travelers by reducing operative cost, and increasing the number of services and their punctuality. To improve the transit system and service, it is necessary to build optimal train scheduling. There is an interest from the industry in automating the scheduling process. Fast computerized train scheduling, moreover, can be used to explore the effects of alternative draft timetables, operating policies, station layouts, and random delays or failures.Postprint (published version

    Deliverable DJRA1.3: Tool prototype for creating and stitching multiple network resources for virtual infrastructures

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    This document describes the prototype FEDERICA Slice Tool developed for the virtualization of network elements in FEDERICA and for creating and stitching network resources over this virtual infrastructure. An SNMP-based resource discovery prototype is also introduced as a new functionality to be integrated in the tool.The deliverable also presents aviability study for the use of traffic prioritization in the FEDERICA infrastructure and some network performance measurements on a real slice within FEDERICA.This document reports the final results of JRA1.2 Activity in the development of a tool prototype for creating sets ofvirtual resourcesinFEDERICA.The prototype goal is to simplify and automate part of the work for NOC.The tool may also serve,with different privileges, a FEDERICA user to operate on his/her slice. The tool described here was designed with the objective of providing an interactive application with a graphical interface to operate on resources for the NOC and the end users (researchers). The tool simplify the creation and configuration of resources in a slice and it is a mandatory step to ensure scalability of the NOC effort. It offers an interactive Graphical User Interface that translates the users’ actions to commands in the substrate (networknodesandV-nodes)andslice elements(VirtualMachines).User accounts may be created for the NOC and for researchers, each with specific privileges to enable different sets of capabilities. The NOC account has full access to all the resources in the substrate, while each user’account has full access only to the virtual resources in his/her slice. The tool has been developed using the Java programming language as Open Source code and relies on the open source Globus® Toolkit. Testing has been performed in a laboratory environment and on some FEDERICA substrate equipment (1switch, 2VMwareServers) in their standard configuration. For testing the router, web services and GUI an additional computer was used, using a public IP address.Postprint (published version

    Self-healing topology discovery protocol for software defined networks

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    “© 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. http://ieeexplore.ieee.org/document/8319433/”This letter presents the design of a self-healing protocol for automatic discovery and maintenance of the network topology in Software Defined Networks (SDN). The proposed protocol integrates two enhanced features (i.e. layer 2 topology discovery and autonomic fault recovery) in a unified mechanism. This novel approach is validated through simulation experiments using OMNET++. Obtained results show that our protocol discovers and recovers the control topology efficiently in terms of time and message load over a wide range of generated networks.Peer ReviewedPostprint (author's final draft

    A framework for the joint placement of edge service infrastructure and User Plane Functions for 5G

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    Achieving less than 1 ms end-to-end communication latency, required for certain 5G services and use cases, is imposing severe technical challenges for the deployment of next-generation networks. To achieve such an ambitious goal, the service infrastructure and User Plane Function (UPF) placement at the network edge, is mandatory. However, this solution implies a substantial increase in deployment and operational costs. To cost-effectively solve this joint placement problem, this paper introduces a framework to jointly address the placement of edge nodes (ENs) and UPFs. Our framework proposal relies on Integer Linear Programming (ILP) and heuristic solutions. The main objective is to determine the ENs and UPFs’ optimal number and locations to minimize overall costs while satisfying the service requirements. To this aim, several parameters and factors are considered, such as capacity, latency, costs and site restrictions. The proposed solutions are evaluated based on different metrics and the obtained results showcase over 20% cost savings for the service infrastructure deployment. Moreover, the gap between the UPF placement heuristic and the optimal solution is equal to only one UPF in the worst cases, and a computation time reduction of over 35% is achieved in all the use cases studied.Postprint (author's final draft

    Energy-aware routing in multiple domains software defined networks

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    The growing energy consumption of communication networks has attracted the attention of the networking researchers in the last decade. In this context, the new architecture of Software-Defined Networks (SDN) allows a flexible programmability, suitable for the power-consumption optimization problem. In this paper we address the issue of designing a novel distributed routing algorithm that optimizes the power consumption in large scale SDN with multiple domains. The solution proposed, called DEAR (Distributed Energy- Aware Routing), tackles the problem of minimizing the number of links that can be used to satisfy a given data traffic demand under performance constraints such as control traffic delay and link utilization. To this end, we present a complete formulation of the optimization problem that considers routing requirements for control and data plane communications. Simulation results confirm that the proposed solution enables the achievement of significant energy savings.Peer ReviewedPostprint (published version

    Discovering the network topology: an efficient approach for SDN

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    Network topology is a physical description of the overall resources in the network. Collecting this information using efficient mechanisms becomes a critical task for important network functions such as routing, network management, quality of service (QoS), among many others. Recent technologies like Software-Defined Networks (SDN) have emerged as promising approaches for managing the next generation networks. In order to ensure a proficient topology discovery service in SDN, we propose a simple agents-based mechanism. This mechanism improves the overall efficiency of the topology discovery process. In this paper, an algorithm for a novel Topology Discovery Protocol (SD-TDP) is described. This protocol will be implemented in each switch through a software agent. Thus, this approach will provide a distributed solution to solve the problem of network topology discovery in a more simple and efficient way.Peer ReviewedPostprint (published version

    A Data Distribution Service in a hierarchical SDN architecture: implementation and evaluation

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    © 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Software-defined networks (SDNs) have caused a paradigm shift in communication networks as they enable network programmability using either centralized or distributed controllers. With the development of the industry and society, new verticals have emerged, such as Industry 4.0, cooperative sensing and augmented reality. These verticals require network robustness and availability, which forces the use of distributed domains to improve network scalability and resilience. To this aim, this paper proposes a new solution to distribute SDN domains by using Data Distribution Services (DDS). The DDS allows the exchange of network information, synchronization among controllers and auto-discovery. Moreover, it increases the control plane robustness, an important characteristic in 5G networks (e.g., if a controller fails, its resources and devices can be managed by other controllers in a short amount of time as they already know this information). To verify the effectiveness of the DDS, we design a testbed by integrating the DDS in SDN controllers and deploying these controllers in different regions of Spain. The communication among the controllers was evaluated in terms of latency and overhead.Postprint (author's final draft

    The Double Feminine Nature and the Medical Gaze: Elsie Venner (1861)

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    Elsie Venner: A Romance of Destiny, written in 1861 by Oliver Wendell Holmes, is a singular novel. Written at a time when medicine was struggling to become a model of professionalization, its singularity lies in the fact that there are four doctors involved in the novel: its author, the narrator of the story and two main characters. Apart from this, out of the three main female characters in the novel, two of them sicken as a consequence of their disobedience to social and moral standards. The novel helps us explore some of the most important issues that were at the center of public debate in nineteenth century medicine: the supposedly pathological nature of female health, the complex relationship between doctor and patient, the consequences of crossing the borders of gender roles, the medical treatment of hysteria, the observational skills of the doctor, the role of the nurse and the threats to healthy reproduction.Elsie Venner: A Romance of Destiny, escrita en 1861 por Oliver Wendell Holmes, es una novela singular. Escrita en una época en que la medicina luchaba por convertirse en un modelo de profesionalización, su singularidad recae en el hecho de que hay cuatro médicos implicados en la novela: su autor, el narrador de la historia y dos personajes principales. Aparte de esto, de los tres personajes femeninos principales en la novela, dos de ellos enferman como consecuencia de su desobediencia a los estándares morales y sociales. La novela nos ayuda a explorar algunas de las cuestiones más importantes que se situaban en el centro del debate público en la medicina del siglo XIX: la supuesta naturaleza patológica de la salud femenina, la compleja relación entre el médico y su paciente, las consecuencias de cruzar las fronteras de los roles de género, el tratamiento médico de la histeria, las destrezas observacionales del médico, el papel de la enfermera y las amenazas a la salud de la reproducción

    A new technique based on mini-UAS for estimating water and bottom radiance contributions in optically shallow waters

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    The mapping of nearshore bathymetry based on spaceborne radiometers is commonly used for QC ocean colour products in littoral waters. However, the accuracy of these estimates is relatively poor with respect to those derived from Lidar systems due in part to the large uncertainties of bottom depth retrievals caused by changes on bottom reflectivity. Here, we present a method based on mini unmanned aerial vehicles (UAS) images for discriminating bottom-reflected and water radiance components by taking advantage of shadows created by different structures sitting on the bottom boundary. Aerial surveys were done with a drone Draganfly X4P during October 1 2013 in optically shallow waters of the Saint Lawrence Estuary, and during low tide. Colour images with a spatial resolution of 3 mm were obtained with an Olympus EPM-1 camera at 10 m height. Preliminary results showed an increase of the relative difference between bright and dark pixels (dP) toward the red wavelengths of the camera's receiver. This is suggesting that dP values can be potentially used as a quantitative proxy of bottom reflectivity after removing artefacts related to Fresnel reflection and bottom adjacency effects.Peer ReviewedPostprint (published version
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