286 research outputs found

    A model of signaling for establishing of LSPs for multicast communication over GMPLS networks

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    Label switching, which in IP networks is exemplified by MPLS and its extensions MPLambdaS and GMPLS, appears as one of the best alternatives to offer a reliable and flexible control plane for WDM networks, since it allows the integration of the IP Protocol with WDM technology, when lambdas are associated with labels, implements powerful traffic-engineering mechanisms, and provides several alternative schemes for fault-tolerance, as well as support for quality of service (QoS). However, almost all the definitions and standardizations for MPLS are restricted to unicast communication, leaving support for multicast communication for future work. In the specific case of the triggering problem for LSPs (Label Switched Paths), there is still no consensus about the best strategy for multicast communication. This paper proposes an algorithm for traffic-driven triggering of LSPs, based on MFCs (Multicast Forwarding Caches), and has the advantage of being a schema which is compatible with several multicast routing protocols. To validate the proposed algorithm we carry out simulation studies using the NS-2 (Network Simulator) simulation platform.5th IFIP International Conference on Network Control & Engineering for QoS, Security and MobilityRed de Universidades con Carreras en Informática (RedUNCI

    Teleprotection signalling over an IP/MPLS network

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    Protection of electricity networks have developed to incorporate communications, referred to as protection signalling. Due to the evolution of the electricity supply system, there are many developments pending within the scope of protection signalling and protection engineering in general. This project investigates the use of current and emerging communications technologies (i.e. packetised networks) being applied and incorporated into current protection signalling schemes and technologies. The purpose of the project is to provide a more cost-effective solution to protection schemes running obsolescent hardware. While the medium-term goal of the industry is to move entirely to IEC 61850 communications, legacy teleprotection relays using non-IP communications will still exist for many years to come. For companies to be ready for an IEC 61850 rollout a fully deployed IP/MPLS network will be necessary and it can be seen that various companies worldwide are readying themselves in this way. However, in the short-term for these companies, this means maintaining their existing TDM network (which runs current teleprotection schemes) and IP/MPLS network. This is a costly business outcome that can be minimised with the migration of services from and decommissioning of TDM networks. Network channel testing was the primary testing focus of the project. The testing proved that teleprotection traffic with correct QoS markings assured the system met latency and stability requirements. Furthermore, MPLS resiliency features (secondary LSPs & Fast-reroute) were tested and proved automatic path failover was possible under fault conditions at sub-30ms speeds

    RSVP- A Fault Tolerant Mechanism in MPLS Networks

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    The data transmission over the Internet (IP) takes an increasingly central role in our communications infrastructure. Here there may be the slow convergence of routing protocols after a network failure becomes a growing problem. To minimize this problem in this paper I am introducing a concept called Multi-protocol label switching (MPLS) will reduce the time convergence and network recovery is limited process when compared to IP. In this paper presents a new efficient fault-tolerance approach for MPLS. And we used a protocol in MPLS based networks to evaluate fast reroute maintain which is RSVP (Resource reservation protocol). And it uses RIP (Routing Information Protocol) algorithm based on distance vector routing and is supported on a wide variety of systems to overcome all the defects in IP. In this paper we simulated the scenarios by using GNS3 (Graphical Network Simulator 3)

    Privacy and Robustness in Federated Learning: Attacks and Defenses

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    As data are increasingly being stored in different silos and societies becoming more aware of data privacy issues, the traditional centralized training of artificial intelligence (AI) models is facing efficiency and privacy challenges. Recently, federated learning (FL) has emerged as an alternative solution and continue to thrive in this new reality. Existing FL protocol design has been shown to be vulnerable to adversaries within or outside of the system, compromising data privacy and system robustness. Besides training powerful global models, it is of paramount importance to design FL systems that have privacy guarantees and are resistant to different types of adversaries. In this paper, we conduct the first comprehensive survey on this topic. Through a concise introduction to the concept of FL, and a unique taxonomy covering: 1) threat models; 2) poisoning attacks and defenses against robustness; 3) inference attacks and defenses against privacy, we provide an accessible review of this important topic. We highlight the intuitions, key techniques as well as fundamental assumptions adopted by various attacks and defenses. Finally, we discuss promising future research directions towards robust and privacy-preserving federated learning.Comment: arXiv admin note: text overlap with arXiv:2003.02133; text overlap with arXiv:1911.11815 by other author

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

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    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

    Study of the Application of Neural Networks in Internet Traffic Engineering

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    In this study, we showed various approachs implemented in Artificial Neural Networks for network resources management and Internet congestion control. Through a training process, Neural Networks can determine nonlinear relationships in a data set by associating the corresponding outputs to input patterns. Therefore, the application of these networks to Traffic Engineering can help achieve its general objective: “intelligent” agents or systems capable of adapting dataflow according to available resources. In this article, we analyze the opportunity and feasibility to apply Artificial Neural Networks to a number of tasks related to Traffic Engineering. In previous sections, we present the basics of each one of these disciplines, which are associated to Artificial Intelligence and Computer Networks respectively

    Simple and stable dynamic traffic engineering for provider scale ethernet

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    Trabalho apresentado no âmbito do Mestrado em Engenharia Informática, como requisito parcial para obtenção do grau de Mestre em Engenharia InformáticaThe high speeds and decreasing costs of Ethernet solutions has motivated providers’ interest in using Ethernet as the link layer technology in their backbone and aggregation networks. Provider scale Ethernet offers further advantages, providing not only an easy to manage solution for multicast traffic, but also transparent interconnection between clients’ LANs. These Ethernet deployments face altogether different design issues, requiring support for a significantly higher number of hosts. This support relies on hierarquization, separating address and virtual network spaces of customers and providers. In addition, large scale Ethernet solutions need to grant forwarding optimality. This can be achieved using traffic engineering approaches. Traffic engineering defines the set of engineering methods and techniques used to optimize the flow of network traffic. Static traffic engineering approaches enjoy widespread use in provider networks, but their performance is greatly penalized by sudden load variations. On the other hand, dynamic traffic engineering is tailored to adapt to load changes. However, providers are skeptical to adopt dynamic approaches as these induce problems such as routing instability, and as a result, network performance decreases. This dissertation presents a Simple and Stable Dynamic Traffic Engineering framework (SSD-TE), which addresses these concerns in a provider scale Ethernet scenario. The validation results show that SSD-TE achieves better or equal performance to static traffic engineering approaches, whilst remaining both stable and responsive to load variations

    Implementing Soak Testing for an Access Network Solution

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    Tietoliikennelaitteiden ohjelmistojen toiminnalle asetetaan erittäin kovat laatuvaatimukset. Operaattoreilla on yleensä asiakkaiden kanssa SLA sopimukset, joiden rikkomisesta operaattorit saattavat joutua maksamaan suuriakin korvauksia. Lisäksi jokainen hetki, jolloin laite ei ole toimintavalmis, tuottaa operaattorille kustannuksia menetettyjen tulojen muodossa. Tämän vuoksi on erittäin tärkeää, että laitteet ovat jatkuvasti toimintakunnossa eikä palvelukatkoksia tule. Tämän diplomityön tavoitteena oli kehittää automatisoitu pitkän ajan testausjärjestelmä IP/MPLS pohjaiselle Tellabs 8600 reititinperheelle. Testattava järjestelmä koostuu useista verkkoelementeistä sekä graafisesta Tellabs 8000 verkonhallintajärjestelmästä. Tämän testausympäristön tavoitteena on paljastaa ongelmia, jotka eivät tule esiin normaalissa toiminnallisessa tai regressiotestauksessa vaan vaativat ilmaantuakseen pidempää ajoaikaa tai useita toistoja. Työssä kehitettiin kehys sille, kuinka testausympäristössä voidaan suorittaa automaattisesti erilaisia operaatioita sekä voidaan ohjelmallisesti havaita mahdollisia ongelmatilanteita. Testausjärjestelmä toteutettiin onnistuneesti ja täyttää sille asetetut tavoitteet. Testausjärjestelmä on otettu käyttöön Tellabsin systeemitestauksessa ja on käyttöönoton jälkeen osoittautunut hyödylliseksi ja tehokkaaksi järjestelmäksi. Systeemitestauksen käyttöön toteutettiin myös toinen täysin identtinen ympäristö.The quality requirements are extremely demanding for telecommunications software. Operators usually have SLA agreements with their customers, and violations to that contract may lead to serious compensations. Furthermore, every moment that equipment or some service is not operating correctly means lost income for the operator. For these reasons, it is extremely important for a telecommunications equipment to continue functioning properly without service affecting breaks. The purpose of this thesis was to design and implement automated soak testing for the IP/MPLS-based Tellabs 8600 router series. The system under test is composed of several network elements and a graphical Tellabs 8000 Network Management System. The purpose of this testing environment is to reveal defects that do not show up immediately in functional or regression testing but may manifest when the system is used for longer periods or operations are executed many times. A framework for automatically operating the test network and detecting problems programmatically was implemented in this thesis. The testing environment was successfully implemented and satisfies the objectives initially set for it. Testing environment has been taken into use in system testing at Tellabs and after deployment has turned out to be useful and effective. Another identical environment was also implemented for the system testing group

    Quality of Service over Specific Link Layers: state of the art report

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    The Integrated Services concept is proposed as an enhancement to the current Internet architecture, to provide a better Quality of Service (QoS) than that provided by the traditional Best-Effort service. The features of the Integrated Services are explained in this report. To support Integrated Services, certain requirements are posed on the underlying link layer. These requirements are studied by the Integrated Services over Specific Link Layers (ISSLL) IETF working group. The status of this ongoing research is reported in this document. To be more specific, the solutions to provide Integrated Services over ATM, IEEE 802 LAN technologies and low-bitrate links are evaluated in detail. The ISSLL working group has not yet studied the requirements, that are posed on the underlying link layer, when this link layer is wireless. Therefore, this state of the art report is extended with an identification of the requirements that are posed on the underlying wireless link, to provide differentiated Quality of Service
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