163 research outputs found

    Optimization of BGP Convergence and Prefix Security in IP/MPLS Networks

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    Multi-Protocol Label Switching-based networks are the backbone of the operation of the Internet, that communicates through the use of the Border Gateway Protocol which connects distinct networks, referred to as Autonomous Systems, together. As the technology matures, so does the challenges caused by the extreme growth rate of the Internet. The amount of BGP prefixes required to facilitate such an increase in connectivity introduces multiple new critical issues, such as with the scalability and the security of the aforementioned Border Gateway Protocol. Illustration of an implementation of an IP/MPLS core transmission network is formed through the introduction of the four main pillars of an Autonomous System: Multi-Protocol Label Switching, Border Gateway Protocol, Open Shortest Path First and the Resource Reservation Protocol. The symbiosis of these technologies is used to introduce the practicalities of operating an IP/MPLS-based ISP network with traffic engineering and fault-resilience at heart. The first research objective of this thesis is to determine whether the deployment of a new BGP feature, which is referred to as BGP Prefix Independent Convergence (PIC), within AS16086 would be a worthwhile endeavour. This BGP extension aims to reduce the convergence delay of BGP Prefixes inside of an IP/MPLS Core Transmission Network, thus improving the networks resilience against faults. Simultaneously, the second research objective was to research the available mechanisms considering the protection of BGP Prefixes, such as with the implementation of the Resource Public Key Infrastructure and the Artemis BGP Monitor for proactive and reactive security of BGP prefixes within AS16086. The future prospective deployment of BGPsec is discussed to form an outlook to the future of IP/MPLS network design. As the trust-based nature of BGP as a protocol has become a distinct vulnerability, thus necessitating the use of various technologies to secure the communications between the Autonomous Systems that form the network to end all networks, the Internet

    Planning tools for MPLS networks

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    Verkot, joissa MPLS-tekniikkaa (Multi Protocol Label Switching) käytetään pakettien reitittämiseen, kasvavat jatkuvasti yhä suuremmiksi ja toiminnallisuus, jota verkoissa tarvitaan, monipuolistuu koko ajan. Tämän syyn vuoksi verkon suunnittelija tarvitsee yhä parempia apuvälineitä, jotta suunnittelu olisi onnistunutta, optimaalista ja tuottaisi halutun tuloksen. Tämän diplomityön tarkoitus on selvittää tärkeimmät toiminnallisuudet ja ominaisuudet, joita MPLS-verkkojen suunnitteluun laadittu työkalu vaatii. Diplomityö on jaettu kolmeen osaan. Ensimmäisessä osassa valotetaan MPLS-verkkojen käyttämää tekniikkaa. Tuossa osiossa käydään läpi tekniikat ja protokollat, joita MPLS-verkot käyttävät erinäisiin tehtäviin. Ensin käydään läpi yleisesti miksi MPLS-tekniikkaa ylipäätään tarvitaan ja miksi sitä käytetään verkkojen reitittämiseen. Tämän jälkeen tarkastellaan MPLS-protokollan otsikkokenttää ja sen osien käyttötarkoitukset selitetään. Sitten tarkastellaan MPLS-verkon rakennetta ja siihen kuuluvia laitteita. Seuraavaksi siirrytään osioon, joka selvittää kaikki yleisesti MPLS-polkujen rakentamiseen käytettävät protokollat ja miten ne eroavat toisistaan. Tämän jälkeen kerrotaan MPLS-vuonohjauksesta Differentiated Services-tekniikan avulla ja siitä miten se auttaa erilaisten liikenneluokkien erittelyssä MPLS-liikenteessä. Viimeinen kohta tässä osassa listaa erilaiset VPN-yhteydet, jotka ovat mahdollisia MPLS-tekniikkaa käytettäessä. Osio selventää näiden tekniikoiden eroavaisuudet ja mahdollisuudet, joita nämä MPLS-tekniikan avulla toteutettavat VPN-yhteydet suovat verrattuna aiempiin VPN-toteutuksiin. Toinen osa tässä diplomityössä kertoo verkon suunnittelusta. Ensin käydään läpi verkon suunnittelua yleisellä tasolla. Tämä osa sisältää verkon suunnittelun eri vaiheet pääosittain: erilaiset ennustusmallit esitellään ja selvitetään mitoituksen ja vuonohjauksen rooli verkkosuunnittelussa. Näiden jälkeen siirrytään yleisestä verkonsunnittelusta osioihin, joita käytetään MPLS-verkon suunnittelussa ja joiden yleisesti oletetaan tai halutaan löytyvän MPLS-verkkoihin tarkoitetusta suunnittelutyökalusta. Viimeinen kohta kertoo toiminnallisuus- ja skaalautuvuushaasteista, joihin MPLS:n on tekniikkana vastattava nykypäivänä. Kolmannessa osiossa tarkastellaan kahta eri suunnittelutyökalua, jotka on laadittu MPLS-verkkojen suunnitelua varten: WANDL-yhtiön julkaisemaa IP/MPLSView:ta ja Aria Networks Oy:n julkaisemaa iVNT:ta. Tässä osiossa käydään läpi näiden työkalujen toiminnallisuutta kertomalla erilaisista simulaatiomahdollisuuksista, joita kumpikin työkalu tarjoaa. Lisäksi kerrotaan mitä toimintoja ja protokollia näihin työkaluihin on mallinnettu, miten hyvin työkalut skaalautuvat kaupallisten MPLS-verkkojen tarpeisiin ja minkälaisita moduuleista työkalut on rakennettu. Työn lopussa on pohdittu näiden kolmen osion perusteella, että mitkä ominaisuudet tulisi ottaa huomioon MPLS-verkon suunnittelutyökalua laadittaessa ja millä tavalla nämä ominaisuudet tulisi toteuttaa työkalussa. Näiden jälkeen on työhön vielä tehty loppuyhteenveto, joka kertoo työ tuloksista ja mahdollisista jatkokehitysmahdollisuuksista. MPLS-verkon suunnittelu koostuu monesta eri vaiheesta, ja jokainen vaihe sisältää suuren määrän toiminnallisuusvaatimuksia. Nämä toiminnallisuusvaatimukset on mallinnettava MPLS-verkkojen suunnitteluun laaditussa työkalussa, jos halutaan että työkalu pystyy mallintamaan koko verkon suunnitteluprosessin alusta loppuun. Tärkeimmät toiminnallisuudet, jotka MPLS-verkon suunnittelutyökalun tulee omata ovat simulointimahdollisuudet MPLS-poluille (LSP:t), MPLS-TE:lle, eri VPN-tyypeille ja DiffServ-liikenteelle, sillä nämä ovat tärkeimmät toiminnallisuudet MPLS-verkoissa tänä päivänä. Jos edellä mainittu toiminnallisuus on toteutettu ja mallinnettu suunnittelutyökalussa ja työkalu osaa optimoida liikennettä hyvin saadaan verkon pääoma- ja operaationaaliset kulut laskemaan. MPLS-verkon suunnittelutyökalua laadittaessa on myös tärkeää ottaa huomioon työkalun skaalautuvuusominaisuudet. Runkoverkot voivat koostua tänä päivänä tuhansista solmuista ja sadoista tuhansista liikennevirroista, joten suunnitelutyökalun tulisi omata toiminnallisuutta joka automatisoi joitain vaiheita verkonsuunnittelussa, mikä mahdollistaa tämän kokoluokan verkkojen suunnittelun. Tällainen toiminnallisuus voisi esimerkiksi olla automatisoitu vuonohjaus ja verkkojen topologiakokonaisuuden vienti ja tuonti suunnittelutyökaluun ja siitä ulos. /Kir1

    Toward Automated Network Management and Operations.

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    Network management plays a fundamental role in the operation and well-being of today's networks. Despite the best effort of existing support systems and tools, management operations in large service provider and enterprise networks remain mostly manual. Due to the larger scale of modern networks, more complex network functionalities, and higher network dynamics, human operators are increasingly short-handed. As a result, network misconfigurations are frequent, and can result in violated service-level agreements and degraded user experience. In this dissertation, we develop various tools and systems to understand, automate, augment, and evaluate network management operations. Our thesis is that by introducing formal abstractions, like deterministic finite automata, Petri-Nets and databases, we can build new support systems that systematically capture domain knowledge, automate network management operations, enforce network-wide properties to prevent misconfigurations, and simultaneously reduce manual effort. The theme for our systems is to build a knowledge plane based on the proposed abstractions, allowing network-wide reasoning and guidance for network operations. More importantly, the proposed systems require no modification to the existing Internet infrastructure and network devices, simplifying adoption. We show that our systems improve both timeliness and correctness in performing realistic and large-scale network operations. Finally, to address the current limitations and difficulty of evaluating novel network management systems, we have designed a distributed network testing platform that relies on network and device virtualization to provide realistic environments and isolation to production networks.Ph.D.Computer Science & EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/78837/1/chenxu_1.pd

    SEMANTIC WEB-BASED MANAGEMENT OF ROUTING CONFIGURATIONS

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    Abstract-Today, network operators typically reason about network behaviour by observing the effects of a particular configuration in operation. This configuration process typically involves logging configuration changes and rolling back to a previous version when a problem arises. Advanced network operators (more each day) use policy-based routing languages to define the routing configuration and tools based on systematic verification techniques to ensure that operational behaviour is consistent with the intended behaviour. These tools help operators to reason about properties of routing protocols. However, these languages and tools work in low-level, i.e. they focus on properties, parameters, and elements of routing protocols. However, network operators receive high-level policies that must be refined to low level parameters before they can be applied. These high-level policies should consider other properties (e.g. extensibility or reasoning capabilities), parameters (e.g. time period, localization or QoS parameters), and elements (e.g. AAA individuals or resources), when the network configuration is defined. We believe that there is a need of broader approaches in languages and tools for defining routing configurations that are more powerful and integrated to other network elements. This article provides the main ideas behind the specification of routing policies using formal languages which enable the description of semantics. (1) Corresponding author; telephone: +34 868 887646; Fax: +34 868 884151 These semantics make easier the policy refinement process and allows describing an automated process for doing conflict detection on these policies

    Communication Technologies Support to Railway Infrastructure and Operations

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    Design and Development of a Framework for Traffic Management in a Global Manufacturing Enterprise: The American Standard Case Study

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    Managed Bandwidth Services (MBSs) use Quality of Service (QoS) guarantees to effectively control traffic flows and reduce network delay. In the past, the provision of MBS in a global manufacturing enterprise was a difficult task for network administrators. However, advances in recently emerging technologies, such as Multiprotocol Label Switching (MPLS), Generalized Multiprotocol Label Switching (GMPLS), Integrated Services (IntServ), Differentiated Services (DiffServ), and Constraint-based Routing (CBR), hold promise to make MBS implementation more manageable. QoS technologies, such as DiffServ and IntServ, offer the benefits of better application performance and delivery of reliable network service. As a consequence of network traffic loads, packet congestion and latency increases still exist and must be addressed by enterprises that intend to support an MBS solution. In this investigation, the author addressed an issue that is faced by many large manufacturing enterprises, i.e., the addition of latency and congestion sensitive traffic such as Voice-over-Internet Protocol (VoIP) to networks with limited bandwidth. The goal of this research was to provide global manufacturing enterprises with a model for bandwidth management in their offices and plants. This model was based on findings from a case study of traffic management at American Standard Companies

    Enabling architectures for QoS provisioning

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    Nowadays, new multimedia services have been deployed with stringent requirements for Quality of Service (QoS). The QoS provisioning is faced with the heterogeneity of system components. This thesis presents two research: on architectures for QoS management at the application layer, fulfilled mainly by software components; and on distributed software architectures for routing devices providing desired QoS at the underlying communication layer. At the application layer, the QoS architecture we propose, based on the Quality Driven Delivery (QDD) framework, deals with the increasing amount of QoS information of a distributed system. Based on various QoS information models we define for key actors of a distributed system, a QoS information base is generated using QoS information collecting and analysis tools. To translate QoS information among different components, we propose mechanisms to build QoS mapping rules from statistical data. Experiments demonstrate that efficient QoS decisions can be made effectively regarding the contribution of all system components with the help of the QoS information management system. At the underlying layer, we investigate distributed and scalable software architectures for QoS-enabled devices. Due to the huge volume of traffic to be switched, the traditional software model used for current generation routers, where the control card of the router performs all the processing tasks, is no longer appropriate in the near future. We propose a new scalable and distributed architecture to fully exploit the hardware platforms of the next generation routers, and to improve the quality of routers, particularly with respect to scalability and to a lesser extent to resiliency and availability. Our proposal is a distributed software framework where control tasks are shared among the control and line cards of the router. Specific architectures for routing, signaling protocols and routing table management are developed. We investigate the challenges for such distributed architectures and proposed various solutions to overcome them. Based on a general distributed software framework, an efficient scalable distributed architecture for MPLS/LDP and different scalable distributed schemes for the routing table manager (RTM) are developed. We also evaluate the performance of proposed distributed schemes and discuss where to deploy these architectures depending on the type of routers (i.e., their hardware capacity

    Strategies for internet route control: past, present and future

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    Uno de los problemas más complejos en redes de computadores es el de proporcionar garantías de calidad y confiabilidad a las comunicaciones de datos entre entidades que se encuentran en dominios distintos. Esto se debe a un amplio conjunto de razones -- las cuales serán analizadas en detalle en esta tesis -- pero de manera muy breve podemos destacar: i) la limitada flexibilidad que presenta el modelo actual de encaminamiento inter-dominio en materia de ingeniería de tráfico; ii) la naturaleza distribuida y potencialmente antagónica de las políticas de encaminamiento, las cuales son administradas individualmente y sin coordinación por cada dominio en Internet; y iii) las carencias del protocolo de encaminamiento inter-dominio utilizado en Internet, denominado BGP (Border Gateway Protocol).El objetivo de esta tesis, es precisamente el estudio y propuesta de soluciones que permitan mejorar drásticamente la calidad y confiabilidad de las comunicaciones de datos en redes conformadas por múltiples dominios.Una de las principales herramientas para lograr este fin, es tomar el control de las decisiones de encaminamiento y las posibles acciones de ingeniería de tráfico llevadas a cabo en cada dominio. Por este motivo, esta tesis explora distintas estrategias de como controlar en forma precisa y eficiente, tanto el encaminamiento como las decisiones de ingeniería de tráfico en Internet. En la actualidad este control reside principalmente en BGP, el cual como indicamos anteriormente, es uno de los principales responsables de las limitantes existentes. El paso natural sería reemplazar a BGP, pero su despliegue actual y su reconocida operatividad en muchos otros aspectos, resultan claros indicadores de que su sustitución (ó su posible evolución) será probablemente gradual. En este escenario, esta tesis propone analizar y contribuir con nuevas estrategias en materia de control de encaminamiento e ingeniería de tráfico inter-dominio en tres marcos temporales distintos: i) en la actualidad en redes IP; ii) en un futuro cercano en redes IP/MPLS (MultiProtocol Label Switching); y iii) a largo plazo en redes ópticas, modelando así una evolución progresiva y realista, facilitando el reemplazo gradual de BGP.Más concretamente, este trabajo analiza y contribuye mediante: - La propuesta de estrategias incrementales basadas en el Control Inteligente de Rutas (Intelligent Route Control, IRC) para redes IP en la actualidad. Las estrategias propuestas en este caso son de carácter incremental en el sentido de que interaccionan con BGP, solucionando varias de las carencias que éste presenta sin llegar a proponer aún su reemplazo. - La propuesta de estrategias concurrentes basadas en extender el concepto del PCE (Path Computation Element) proveniente del IETF (Internet Engineering Task Force) para redes IP/MPLS en un futuro cercano. Las estrategias propuestas en este caso son de carácter concurrente en el sentido de que no interaccionan con BGP y pueden ser desplegadas en forma paralela. En este caso, BGP continúa controlando el encaminamiento y las acciones de ingeniería de tráfico inter-dominio del tráfico IP, pero el control del tráfico IP/MPLS se efectúa en forma independiente de BGP mediante los PCEs.- La propuesta de estrategias que reemplazan completamente a BGP basadas en la incorporación de un nuevo agente de control, al cual denominamos IDRA (Inter-Domain Routing Agent). Estos agentes proporcionan un plano de control dedicado, físicamente independiente del plano de datos, y con gran capacidad computacional para las futuras redes ópticas multi-dominio.Los resultados expuestos aquí validan la efectividad de las estrategias propuestas, las cuales mejoran significativamente tanto la concepción como la performance de las actuales soluciones en el área de Control Inteligente de Rutas, del esperado PCE en un futuro cercano, y de las propuestas existentes para extender BGP al área de redes ópticas.One of the most complex problems in computer networks is how to provide guaranteed performance and reliability to the communications carried out between nodes located in different domains. This is due to several reasons -- which will be analyzed in detail in this thesis -- but in brief, this is mostly due to: i) the limited capabilities of the current inter-domain routing model in terms of Traffic Engineering (TE); ii) the distributed and potentially conflicting nature of policy-based routing, where routing policies are managed independently and without coordination among domains; and iii) the clear limitations of the inter-domain routing protocol, namely, the Border Gateway Protocol (BGP). The goal of this thesis is precisely to study and propose solutions allowing to drastically improve the performance and reliability of inter-domain communications. One of the most important tools to achieve this goal, is to control the routing and TE decisions performed by routing domains. Therefore, this thesis explores different strategies on how to control such decisions in a highly efficient and accurate way. At present, this control mostly resides in BGP, but as mentioned above, BGP is in fact one of the main causes of the existing limitations. The natural next-step would be to replace BGP, but the large installed base at present together with its recognized effectiveness in other aspects, are clear indicators that its replacement (or its possible evolution) will probably be gradually put into practice.In this framework, this thesis proposes to to study and contribute with novel strategies to control the routing and TE decisions of domains in three different time frames: i) at present in IP multi-domain networks; ii) in the near-future in IP/MPLS (MultiProtocol Label Switching) multi- domain networks; and iii) in the future optical Internet, modeling in this way a realistic and progressive evolution, facilitating the gradual replacement of BGP.More specifically, the contributions in this thesis can be summarized as follows. - We start by proposing incremental strategies based on Intelligent Route Control (IRC) solutions for IP networks. The strategies proposed in this case are incremental in the sense that they interact with BGP, and tackle several of its well-known limitations. - Then, we propose a set of concurrent route control strategies for MPLS networks, based on broadening the concept of the Path Computation Element (PCE) coming from the IETF (Internet Engineering Task Force). Our strategies are concurrent in the sense that they do not interact directly with BGP, and they can be deployed in parallel. In this case, BGP still controlls the routing and TE actions concerning regular IP-based traffic, but not how IP/MPLS paths are routed and controlled. These are handled independently by the PCEs.- We end with the proposal of a set of route control strategies for multi-domain optical networks, where BGP has been completely replaced. These strategies are supported by the introduction of a new route control element, which we named Inter-Domain Routing Agent (IDRA). These IDRAs provide a dedicated control plane, i.e., physically independent from the data plane, and with high computational capacity for future optical networks.The results obtained validate the effectiveness of the strategies proposed here, and confirm that our proposals significantly improve both the conception and performance of the current IRC solutions, the expected PCE in the near-future, as well as the existing proposals about the optical extension of BGP.Postprint (published version
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