1,456 research outputs found
Quality of service assurance for the next generation Internet
The provisioning for multimedia applications has been of increasing interest among researchers and Internet Service Providers. Through the migration from resource-based to service-driven networks, it has become evident that the Internet model should be enhanced to provide support for a variety of differentiated services that match applications and customer requirements, and not stay limited under the flat best-effort service that is currently provided.
In this paper, we describe and critically appraise the major achievements of the efforts to introduce Quality of Service (QoS) assurance and provisioning within the Internet model. We then propose a research path for the creation of a network services management architecture,
through which we can move towards a QoS-enabled network environment, offering support for a variety of different services, based on traffic characteristics and user expectations
Network layer access control for context-aware IPv6 applications
As part of the Lancaster GUIDE II project, we have developed a novel wireless access point protocol designed to support the development of next generation mobile context-aware applications in our local environs. Once deployed, this architecture will allow ordinary citizens secure, accountable and convenient access to a set of tailored applications including location, multimedia and context based services, and the public Internet. Our architecture utilises packet marking and network level packet filtering techniques within a modified Mobile IPv6 protocol stack to perform access control over a range of wireless network technologies. In this paper, we describe the rationale for, and components of, our architecture and contrast our approach with other state-of-the- art systems. The paper also contains details of our current implementation work, including preliminary performance measurements
Evolving SDN for Low-Power IoT Networks
Software Defined Networking (SDN) offers a flexible and scalable architecture
that abstracts decision making away from individual devices and provides a
programmable network platform. However, implementing a centralized SDN
architecture within the constraints of a low-power wireless network faces
considerable challenges. Not only is controller traffic subject to jitter due
to unreliable links and network contention, but the overhead generated by SDN
can severely affect the performance of other traffic. This paper addresses the
challenge of bringing high-overhead SDN architecture to IEEE 802.15.4 networks.
We explore how traditional SDN needs to evolve in order to overcome the
constraints of low-power wireless networks, and discuss protocol and
architectural optimizations necessary to reduce SDN control overhead - the main
barrier to successful implementation. We argue that interoperability with the
existing protocol stack is necessary to provide a platform for controller
discovery and coexistence with legacy networks. We consequently introduce
{\mu}SDN, a lightweight SDN framework for Contiki, with both IPv6 and
underlying routing protocol interoperability, as well as optimizing a number of
elements within the SDN architecture to reduce control overhead to practical
levels. We evaluate {\mu}SDN in terms of latency, energy, and packet delivery.
Through this evaluation we show how the cost of SDN control overhead (both
bootstrapping and management) can be reduced to a point where comparable
performance and scalability is achieved against an IEEE 802.15.4-2012 RPL-based
network. Additionally, we demonstrate {\mu}SDN through simulation: providing a
use-case where the SDN configurability can be used to provide Quality of
Service (QoS) for critical network flows experiencing interference, and we
achieve considerable reductions in delay and jitter in comparison to a scenario
without SDN
The internet: A global telecommunications solution?
The provision and support of new distributed multimedia services are of prime concern for telecommunications operators and suppliers. Clearly, the potential of the latest Internet protocols to contribute communications components is of considerable interest to them. In this article we first review some of the new types of application and their requirements, and identify the need to support applications that have strict QoS requirements, the so-called critical applications. We review two proposals for enhancing the Internet service architecture. In addition to the integrated services work of the IETF, we look at the more recent proposals for differentiated services in the Internet. We then individually review recent protocol developments proposed to improve the Internet, and to support real-time and multimedia communications. These are IPv6 (the new version of the Internet Protocol), Resource reSerVation Protocol, and Multiprotocol Label Switching, respectively. In each case, we attempt to provide critical reviews in order to assess their suitability for this purpose. Finally, we indicate what the basis of the future infrastructure might be in order to support the full variety of application requirements
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Towards scalable end-to-end QoS provision for VoIP applications
The growth of the Internet and the development of its new applications have increased the demand for providing a certain level of resource assurance and service support. The concept of ensuring quality of service (QoS) has been introduced in order to provide the support and assurance for these services. Different QoS mechanisms, such as integrated services (IntServ) and differentiated services (DiffServ), have been developed and introduced to provide different levels of QoS provision. However, IntServ can suffer from scalability issues that make it infeasible for large-scale network implementations. On the other hand, the aggregated-based per-flow technique of DiffServ does not provide such an end-to-end QoS guarantee. Recently, the IETF have proposed a new QoS architecture that implements IntServ over DiffServ in order to provide an end-to-end QoS for scalable networks. Hence, it became possible to provide and support a certain level of QoS for some delay sensitive and bandwidth-demanding applications such as voice over Internet Protocol (VoIP). With regard to VoIP applications, delay, jitter and packet loss are crucial issues that have to be taken into consideration for any VoIP system design and such parameters need a distinct level of QoS support
A practical approach to network-based processing
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
Mobile IP: state of the art report
Due to roaming, a mobile device may change its network attachment each time it moves to a new link. This might cause a disruption for the Internet data packets that have to reach the mobile node. Mobile IP is a protocol, developed by the Mobile IP Internet Engineering Task Force (IETF) working group, that is able to inform the network about this change in network attachment such that the Internet data packets will be delivered in a seamless way to the new point of attachment. This document presents current developments and research activities in the Mobile IP area
New Challenges in Quality of Services Control Architectures in Next Generation Networks
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 aixĂ 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 Ă©s el control de la Qualitat del Servei (QoS), especialment crĂtic en les comunicacions multimèdia a travĂ©s de xarxes heterogènies i/o de diferents operadors. A mĂ©s a mĂ©s, 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 estĂ enfocada des d'un punt de vista prĂ ctic. AixĂ 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'implementaciĂł i dels tests de conformĂ ncia i interoperabilitat existents que avaluen la qualitat d'aquestes implementacions. A continuaciĂł s'avalua la qualitat de cinc sistemes operatius que suporten IPv6 mitjançant un test de conformĂ ncia i s'implementa el testbed IPv6 bĂ sic, a partir del qual es farĂ la recerca, amb la implementaciĂł que ofereix mĂ©s garanties.El QoS Broker Ă©s l'aportaciĂł principal d'aquesta tesi: un marc integrat que inclou un sistema automatitzat per gestionar el control de la QoS a travĂ©s de sistemes multi-domini/multi-operador seguint les recomanacions de les NGN. El sistema automatitza els mecanismes associats a la configuraciĂł de la QoS dins d'un mateix domini (sistema autònom) mitjançant la gestiĂł basada en polĂtiques de QoS i automatitza la negociaciĂł dinĂ mica 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 tambĂ© xarxes PLC. Aquesta tesi proposa una aproximaciĂł 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'aplicaciĂł sobre les futures xarxes de comunicaciĂł de les Smart Grids.Finalment, s'integra en el QoS Broker un mòdul per gestionar l'enginyeria del trĂ fic optimitzant els dominis mitjançant tècniques de intel·ligència artificial. La validaciĂł en simulacions i sobre un testbed amb routers Cisco demostra que els algorismes genètics hĂbrids sĂłn una opciĂł eficaç en aquest camp.En general, les observacions i avenços assolits en aquesta tesi contribueixen a augmentar la comprensiĂł del funcionament de la QoS en les NGN i a preparar aquests sistemes per afrontar problemes del mĂłn 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 asĂ 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 crĂtico en las comunicaciones multimedia a travĂ©s de redes heterogĂ©neas y/o de diferentes operadores. Además, las NGN incorporan nativamente el protocolo IPv6 que, a pesar de las deficiencias y agotamiento de direcciones IPv4, aĂşn no ha tenido el impulso definitivo.Esta tesis está enfocada desde un punto de vista práctico. AsĂ pues, con tal de poder hacer investigaciĂłn sobre redes de prueba (o testbeds) que suporten IPv6 con garantĂas de funcionamiento, se hace un estudio en profundidad del protocolo IPv6, de su grado de implementaciĂłn y de los tests de conformancia e interoperabilidad existentes que evalĂşan la calidad de estas implementaciones. A continuaciĂłn 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 investigaciĂłn, con la implementaciĂłn que ofrece más garantĂas.El QoS Broker es la aportaciĂłn principal de esta tesis: un marco integrado que incluye un sistema automatitzado para gestionar el control de la QoS a travĂ©s de sistemas multi-dominio/multi-operador siguiendo las recomendaciones de las NGN. El sistema automatiza los mecanismos asociados a la configuraciĂłn de la QoS dentro de un mismo dominio (sistema autĂłnomo) mediante la gestiĂłn basada en polĂticas de QoS y automatiza la negociaciĂłn 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 tambiĂ©n redes PLC. Esta tesis propone una aproximaciĂłn teĂłrica 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 aplicaciĂłn sobre las futuras redes de comunicaciĂłn de las Smart Grids.Finalmente, se integra en el QoS Broker un mĂłdulo para gestionar la ingenierĂa del tráfico optimizando los dominios mediante tĂ©cnicas de inteligencia artificial. La validaciĂłn en simulaciones y sobre un testbed con routers Cisco demuestra que los algoritmos genĂ©ticos hĂbridos son una opciĂłn eficaz en este campo.En general, las observaciones y avances i avances alcanzados en esta tesis contribuyen a augmentar la comprensiĂłn 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
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