471 research outputs found

    A practical approach to network-based processing

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    The usage of general-purpose processors externally attached to routers to play virtually the role of active coprocessors seems a safe and cost-effective approach to add active network capabilities to existing routers. This paper reviews this router-assistant way of making active nodes, addresses the benefits and limitations of this technique, and describes a new platform based on it using an enhanced commercial router. The features new to this type of architecture are transparency, IPv4 and IPv6 support, and full control over layer 3 and above. A practical experience with two applications for path characterization and a transport gateway managing multi-QoS is described.Most of this work has been funded by the IST project GCAP (Global Communication Architecture and Protocols for new QoS services over IPv6 networks) IST-1999-10 504. Further development and application to practical scenarios is being supported by IST project Opium (Open Platform for Integration of UMTS Middleware) IST-2001-36063 and the Spanish MCYT under projects TEL99-0988-C02-01 and AURAS TIC2001-1650-C02-01.Publicad

    New Challenges in Quality of Services Control Architectures in Next Generation Networks

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    A mesura que Internet i les xarxes IP s'han anat integrant dins la societat i les corporacions, han anat creixent les expectatives de nous serveis convergents així com les expectatives de qualitat en les comunicacions. Les Next Generation Networks (NGN) donen resposta a les noves necessitats i representen el nou paradigma d'Internet a partir de la convergència IP. Un dels aspectes menys desenvolupats de les NGN és el control de la Qualitat del Servei (QoS), especialment crític en les comunicacions multimèdia a través de xarxes heterogènies i/o de diferents operadors. A més a més, les NGN incorporen nativament el protocol IPv6 que, malgrat les deficiències i esgotament d'adreces IPv4, encara no ha tingut l'impuls definitiu.Aquesta tesi està enfocada des d'un punt de vista pràctic. Així doncs, per tal de poder fer recerca sobre xarxes de proves (o testbeds) que suportin IPv6 amb garanties de funcionament, es fa un estudi en profunditat del protocol IPv6, del seu grau d'implementació i dels tests de conformància i interoperabilitat existents que avaluen la qualitat d'aquestes implementacions. A continuació s'avalua la qualitat de cinc sistemes operatius que suporten IPv6 mitjançant un test de conformància i s'implementa el testbed IPv6 bàsic, a partir del qual es farà la recerca, amb la implementació que ofereix més garanties.El QoS Broker és l'aportació principal d'aquesta tesi: un marc integrat que inclou un sistema automatitzat per gestionar el control de la QoS a través de sistemes multi-domini/multi-operador seguint les recomanacions de les NGN. El sistema automatitza els mecanismes associats a la configuració de la QoS dins d'un mateix domini (sistema autònom) mitjançant la gestió basada en polítiques de QoS i automatitza la negociació dinàmica de QoS entre QoS Brokers de diferents dominis, de forma que permet garantir QoS extrem-extrem sense fissures. Aquesta arquitectura es valida sobre un testbed de proves multi-domini que utilitza el mecanisme DiffServ de QoS i suporta IPv6.L'arquitectura definida en les NGN permet gestionar la QoS tant a nivell 3 (IP) com a nivell 2 (Ethernet, WiFi, etc.) de forma que permet gestionar també xarxes PLC. Aquesta tesi proposa una aproximació teòrica per aplicar aquesta arquitectura de control, mitjançant un QoS Broker, a les noves xarxes PLC que s'estan acabant d'estandarditzar, i discuteix les possibilitats d'aplicació sobre les futures xarxes de comunicació de les Smart Grids.Finalment, s'integra en el QoS Broker un mòdul per gestionar l'enginyeria del tràfic optimitzant els dominis mitjançant tècniques de intel·ligència artificial. La validació en simulacions i sobre un testbed amb routers Cisco demostra que els algorismes genètics híbrids són una opció eficaç en aquest camp.En general, les observacions i avenços assolits en aquesta tesi contribueixen a augmentar la comprensió del funcionament de la QoS en les NGN i a preparar aquests sistemes per afrontar problemes del món real de gran complexitat.A medida que Internet y las redes IP se han ido integrando dentro de la sociedad y las corporaciones, han ido creciendo las expectativas de nuevos servicios convergentes así como las expectativas de calidad en las comunicaciones. Las Next Generation Networks (NGN) dan respuesta a las nuevas necesidades y representan el nuevo paradigma de Internet a partir de la convergencia IP. Uno de los aspectos menos desarrollados de las NGN es el control de la Calidad del Servicio (QoS), especialmente crítico en las comunicaciones multimedia a través de redes heterogéneas y/o de diferentes operadores. Además, las NGN incorporan nativamente el protocolo IPv6 que, a pesar de las deficiencias y agotamiento de direcciones IPv4, aún no ha tenido el impulso definitivo.Esta tesis está enfocada desde un punto de vista práctico. Así pues, con tal de poder hacer investigación sobre redes de prueba (o testbeds) que suporten IPv6 con garantías de funcionamiento, se hace un estudio en profundidad del protocolo IPv6, de su grado de implementación y de los tests de conformancia e interoperabilidad existentes que evalúan la calidad de estas implementaciones. A continuación se evalua la calidad de cinco sistemas operativos que soportan IPv6 mediante un test de conformancia y se implementa el testbed IPv6 básico, a partir del cual se realizará la investigación, con la implementación que ofrece más garantías.El QoS Broker es la aportación principal de esta tesis: un marco integrado que incluye un sistema automatitzado para gestionar el control de la QoS a través de sistemas multi-dominio/multi-operador siguiendo las recomendaciones de las NGN. El sistema automatiza los mecanismos asociados a la configuración de la QoS dentro de un mismo dominio (sistema autónomo) mediante la gestión basada en políticas de QoS y automatiza la negociación dinámica de QoS entre QoS brokers de diferentes dominios, de forma que permite garantizar QoS extremo-extremo sin fisuras. Esta arquitectura se valida sobre un testbed de pruebas multi-dominio que utiliza el mecanismo DiffServ de QoS y soporta IPv6. La arquitectura definida en las NGN permite gestionar la QoS tanto a nivel 3 (IP) o como a nivel 2 (Ethernet, WiFi, etc.) de forma que permite gestionar también redes PLC. Esta tesis propone una aproximación teórica para aplicar esta arquitectura de control, mediante un QoS Broker, a las noves redes PLC que se están acabando de estandardizar, y discute las posibilidades de aplicación sobre las futuras redes de comunicación de las Smart Grids.Finalmente, se integra en el QoS Broker un módulo para gestionar la ingeniería del tráfico optimizando los dominios mediante técnicas de inteligencia artificial. La validación en simulaciones y sobre un testbed con routers Cisco demuestra que los algoritmos genéticos híbridos son una opción eficaz en este campo.En general, las observaciones y avances i avances alcanzados en esta tesis contribuyen a augmentar la comprensión del funcionamiento de la QoS en las NGN y en preparar estos sistemas para afrontar problemas del mundo real de gran complejidad.The steady growth of Internet along with the IP networks and their integration into society and corporations has brought with it increased expectations of new converged services as well as greater demands on quality in communications. The Next Generation Networks (NGNs) respond to these new needs and represent the new Internet paradigm from the IP convergence. One of the least developed aspects in the NGNs is the Quality of Service (QoS) control, which is especially critical in the multimedia communication through heterogeneous networks and/or different operators. Furthermore, the NGNs natively incorporate the IPv6 protocol which, despite its shortcomings and the depletion of IPv4 addresses has not been boosted yet.This thesis has been developed with a practical focus. Therefore, with the aim of carrying out research over testbeds supporting the IPv6 with performance guarantees, an in-depth study of the IPv6 protocol development has been conducted and its degree of implementation and the existing conformance and interoperability tests that evaluate these implementations have been studied. Next, the quality of five implementations has been evaluated through a conformance test and the basic IPv6 testbed has been implemented, from which the research will be carried out. The QoS Broker is the main contribution to this thesis: an integrated framework including an automated system for QoS control management through multi-domain/multi-operator systems according to NGN recommendations. The system automates the mechanisms associated to the QoS configuration inside the same domain (autonomous system) through policy-based management and automates the QoS dynamic negotiation between peer QoS Brokers belonging to different domains, so it allows the guarantee of seamless end-to-end QoS. This architecture is validated over a multi-domain testbed which uses the QoS DiffServ mechanism and supports IPv6.The architecture defined in the NGN allows QoS management at level 3 (IP) as well as at level 2 (e.g. Ethernet, WiFi) so it also facilitates the management of PLC networks. Through the use of a QoS Broker, this thesis proposes a theoretical approach for applying this control architecture to the newly standardized PLC networks, and discusses the possibilities of applying it over the future communication networks of the Smart Grids.Finally, a module for managing traffic engineering which optimizes the network domains through artificial intelligence techniques is integrated in the QoS Broker. The validations by simulations and over a Cisco router testbed demonstrate that hybrid genetic algorithms are an effective option in this area.Overall, the advances and key insights provided in this thesis help advance our understanding of QoS functioning in the NGNs and prepare these systems to face increasingly complex problems, which abound in current industrial and scientific applications

    Case Study - IPv6 based building automation solution integration into an IPv4 Network Service Provider infrastructure

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    The case study presents a case study describing an Internet Protocol (IP) version 6 (v6) introduction to an IPv4 Internet Service Provider (ISP) network infrastructure. The case study driver is an ISP willing to introduce a new “killer” service related to Internet of Things (IoT) style building automation. The provider and cooperation of third party companies specialized in building automation will provide the service. The ISP has to deliver the network access layer and to accommodate the building automation solution traffic throughout its network infrastructure. The third party companies are system integrators and building automation solution vendors. IPv6 is suitable for such solutions due to the following reasons. The operator can’t accommodate large number of IPv4 embedded devices in its current network due to the lack of address space and the fact that many of those will need clear 2 way IP communication channel. The Authors propose a strategy for IPv6 introduction into operator infrastructure based on the current network architecture present service portfolio and several transition mechanisms. The strategy has been applied in laboratory with setup close enough to the current operator’s network. The criterion for a successful experiment is full two-way IPv6 application layer connectivity between the IPv6 server and the IPv6 Internet of Things (IoT) cloud

    MUST, SHOULD, DON'T CARE: TCP Conformance in the Wild

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    Standards govern the SHOULD and MUST requirements for protocol implementers for interoperability. In case of TCP that carries the bulk of the Internets' traffic, these requirements are defined in RFCs. While it is known that not all optional features are implemented and nonconformance exists, one would assume that TCP implementations at least conform to the minimum set of MUST requirements. In this paper, we use Internet-wide scans to show how Internet hosts and paths conform to these basic requirements. We uncover a non-negligible set of hosts and paths that do not adhere to even basic requirements. For example, we observe hosts that do not correctly handle checksums and cases of middlebox interference for TCP options. We identify hosts that drop packets when the urgent pointer is set or simply crash. Our publicly available results highlight that conformance to even fundamental protocol requirements should not be taken for granted but instead checked regularly

    CLOCIS:Cloud-based conformance testing framework for IoT devices in the future internet

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    In recent years, the Internet of Things (IoT) has not only become ubiquitous in daily life but has also emerged as a pivotal technology across various sectors, including smart factories and smart cities. Consequently, there is a pressing need to ensure the consistent and uninterrupted delivery of IoT services. Conformance testing has thus become an integral aspect of IoT technologies. However, traditional methods of IoT conformance testing fall short of addressing the evolving requirements put forth by both industry and academia. Historically, IoT testing has necessitated a visit to a testing laboratory, implying that both the testing systems and testers must be co-located. Furthermore, there is a notable absence of a comprehensive method for testing an array of IoT standards, especially given their inherent heterogeneity. With a surge in the development of diverse IoT standards, crafting an appropriate testing environment poses challenges. To address these concerns, this article introduces a method for remote IoT conformance testing, underpinned by a novel conceptual architecture termed CLOCIS. This architecture encompasses an extensible approach tailored for a myriad of IoT standards. Moreover, we elucidate the methods and procedures integral to testing IoT devices. CLOCIS, predicated on this conceptual framework, is actualized, and to attest to its viability, we undertake IoT conformance testing and present the results. When leveraging CLOCIS, small and medium-sized enterprises (SMEs) and entities in the throes of IoT service development stand to benefit from a reduced time to market and cost-efficient testing procedures. Additionally, this innovation holds promise for IoT standardization communities, enabling them to champion their standards with renewed vigor
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