31 research outputs found

    Final Report - Dynamic Path Scheduling through Extensions to Generalized Multiprotocol Label Switching (GMPLS)

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    Topology forming and optimization framework for heterogeneous wireless back-haul networks supporting unidirectional technologies

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    Wireless operators, in developed or emerging regions, must support triple-play service offerings as demanded by the market or mandated by regulatory bodies through so-called Universal Service Obligations (USOs). Since individual operators might face different constraints such as available spectrum licenses, technologies, cost structures or a low energy footprint, the EU FP7 CARrier grade wireless MEsh Network (CARMEN) project has developed a carrier-grade heterogeneous multi-radio back-haul architecture which may be deployed to extend, complement or even replace traditional operator equipment. To support offloading of live triple-play content to broadcast-optimized, e.g., DVB-T, overlay cells, this heterogeneous wireless back-haul architecture integrates unidirectional broadcast technologies. In order to manage the physical and logical resources of such a network, a centralized coordinator approach has been chosen, where no routing state is kept at plain WiBACK Nodes (WNs) which merely store QoS-aware MPLS forwarding state. In this paper we present our Unidirectional Technology (UDT)-aware design of the centralized Topology Management Function (TMF), which provides a framework for different topology and spectrum allocation optimization strategies and algorithms to be implemented. Following the validation of the design, we present evaluation results using a hybrid local/centralized topology optimizer showing that our TMF design supports the reliable forming of optimized topologies as well as the timely recovery from node failures.Federal Ministry of Education and Research of the Federal Republic of German (F篓orderkennzeichen 01 BU1116,SolarMesh Energieeffizientes,autonomesgro脽fl篓achiges Sprach- undDatenfunknetzmitflacher IP-Architektur

    On the resource abstraction, partitioning and composition for virtual GMPLS-controlled multi-layer optical networks

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    Virtual optical networking supports the dynamic provisioning of dedicated networks over the same network infrastructure, which has received a lot of attention by network providers. The stringent network requirements (e.g., Quality of Service -QoS-, Service Level Agreement -SLA-, dynamicity) of the emerging high bandwidth and dynamic applications such as high-definition video streaming (e.g., telepresence, television, remote surgery, etc.), and cloud computing (e.g., real-time data backup, remote desktop, etc.) can be supported by the deployment of dynamic infrastructure services to build ad-hoc Virtual Optical Networks (VON), which is known as Infrastructure as a Service (IaaS). Future Internet should support two separate entities: infrastructure providers (who manage the physical infrastructure) and service providers (who deploy network protocols and offer end-to-end services). Thus, network service providers shall request, on a per-need basis, a dedicated and application-specific VON and have full control over it. Optical network virtualization technologies allow the partitioning/composition of the network infrastructure (i.e., physical optical nodes and links) into independent virtual resources, adopting the same functionality as the physical resource. The composition of these virtual resources (i.e., virtual optical nodes and links) allows the deployment of multiple VONs. A VON must be composed of not only a virtual transport plane but also of a virtual control plane, with the purpose of providing the required independent and full control functionalities (i.e., automated connection provisioning and recovery (protection/restauration), traffic engineering (e.g., QoS, SLA), etc.). This PhD Thesis focuses on optical network virtualization, with three main objectives. The first objective consists on the design, implementation and evaluation of an architecture and the necessary protocols and interfaces for the virtualization of a Generalized Multi-Protocol Label Switching (GMPLS) controlled Wavelength Switched Optical Network (WSON) and the introduction of a resource broker for dynamic virtual GMPLS-controlled WSON infrastructure services, whose task is to dynamically deploy VONs from service provider requests. The introduction of a resource broker implies the need for virtual resource management and allocation algorithms for optimal usage of the shared physical infrastructure. Also, the deployment of independent virtual GMPLS control plane on top of each VON shall be performed by the resource broker. This objective also includes the introduction of optical network virtualization for Elastic Optical Networks (EON). The second objective is to design, implement and experimentally evaluate a system architecture for deploying virtual GMPLS-controlled Multi-Protocol Label Switching Transport Profile (MPLS-TP) networks over a shared WSON. With this purpose, this PhD Thesis also focuses on the design and development of MPLS-TP nodes which are deployed on the WSON of the ADRENALINE Testbed at CTTC premises. Finally, the third objective is the composition of multiple virtual optical networks with heterogeneous control domains (e.g., GMPLS, OpenFlow). A multi-domain resource broker has been designed, implemented and evaluated.La gesti贸 de xarxes 貌ptiques virtuals permet la provisi贸 din脿mica de xarxes dedicades a sobre la mateixa infraestructura de xarxa i ha cridat molt l鈥檃tenci贸 als prove茂dors de xarxes. Els requisits de xarxa (per exemple la qualitat de servei, els acords de nivell de servei o la dinamicitat) s贸n cada cop m茅s astringents per a les aplicacions emergents d'elevat ample de banda i din脿miques, que inclouen per exemple la reproducci贸 en temps real de v铆deo d'alta definici贸 (telepres猫ncia, televisi贸, telemedicina) i serveis d鈥檌nform脿tica en n煤vol (c貌pies de seguretat en temps real, escriptori remot). Aquests requisits poden ser assolits a trav茅s del desplegament de serveis de infraestructura din脿mics per construir xarxes 貌ptiques virtuals (VON, en angl猫s), fet que 茅s conegut com a infraestructura com a servei (IaaS). La internet del futur hauria de suportar dos entitats diferenciades: els prove茂dors d'infraestructures (responsables de gestionar la infraestructura f铆sica), i els prove茂dors de serveis (responsables dels protocols de xarxa i d'oferir els serveis finals). D'aquesta forma els prove茂dors de serveis podrien sol鈥icitar i gestionar en funci贸 de les necessitats xarxes 貌ptiques virtuals dedicades i espec铆fiques per les aplicacions. Les tecnologies de virtualitzaci贸 de xarxes 貌ptiques virtuals permeten la partici贸 i composici贸 de infraestructura de xarxa (nodes i enlla莽os 貌ptics) en recursos virtuals independents que adopten les mateixes funcionalitats que els recursos f铆sics. La composici贸 d'aquests recursos virtuals (nodes i enlla莽os 貌ptics virtuals) permet el desplegament de m煤ltiples VONs. Una VON no sols est脿 composada per un pla de transport virtual, sin贸 tamb茅 per un pla de control virtual, amb l'objectiu d'incorporar les funcionalitats necess脿ries a la VON (provisi贸 de connexions autom脿tiques i recuperaci贸 (protecci贸/restauraci贸), enginyeria de tr脿fic, etc.). Aquesta tesis es centra en la virtualitzaci贸 de xarxes 貌ptiques amb tres objectius principals. El primer objectiu consisteix en el disseny, implementaci贸 i avaluaci贸 de l'arquitectura i els protocols i interf铆cies necessaris per la virtualitzaci贸 de xarxes encaminades a trav茅s de la longitud d'ona i controlades per GMPLS. Tamb茅 inclou la introducci贸 d'un gestor de recursos per desplegar xarxes 貌ptiques virtuals de forma din脿mica. La introducci贸 d'aquest gestor de recursos implica la necessitat d'una gesti贸 dels recursos virtuals i d鈥檃lgoritmes d鈥檃ssignaci贸 de recursos per a la utilitzaci贸 貌ptima dels recursos f铆sics. A m茅s el gestor de recursos ha de ser capa莽 del desplegament dels recursos assignats, incloent un pla de control GMPLS virtual independent per a cada VON desplegada. Finalment, aquest objectiu inclou la introducci贸 de mecanismes de virtualitzaci贸 per a xarxes el脿stiques 貌ptiques (EON, en angl猫s). El segon objectiu 茅s el disseny, la implementaci贸 i l鈥檃valuaci贸 experimental d'una arquitectura de sistema per oferir xarxes MPLS-TP virtuals controlades per GMPLS sobre una infraestructura i WSON compartida. Per aix貌, aquesta tesis tamb茅 es centra en el disseny i desenvolupament d'un node MPLS-TP que ha estat desplegat al demostrador ADRENALINE, al CTTC. Finalment, el tercer objectiu 茅s la composici贸 de m煤ltiples xarxes 貌ptiques virtuals en dominis de control heterogenis (GMPLS i OpenFlow). Un gestor de recursos multi-domini ha estat dissenyat, implementat i avaluat.La gesti贸n de redes 贸pticas virtuales permite la provisi贸n din谩mica de redes dedicadas encima la misma infraestructura de red y ha llamado mucho la atenci贸n a los proveedores de redes. Los requisitos de red (por ejemplo la calidad de servicio, los acuerdos de nivel de servicio o la dinamicidad) son cada vez m谩s estringentes para las aplicaciones emergentes de elevado ancho de banda y din谩micas, que incluyen por ejemplo la reproducci贸n en tiempo real de v铆deo de alta definici贸n (telepresencia, televisi贸n, telemedicina) y servicios de computaci贸n en la nube (copias de seguridad en tiempo real, escritorio remoto). Estos requisitos pueden ser logrados a trav茅s del despliegue de servicios de infraestructura din谩micos para construir redes 贸pticas virtuales (VON, en ingl茅s), hecho que es conocido como infraestructura como servicio (IaaS). La internet del futuro tendr谩 que soportar dos entidades diferenciadas: los proveedores de infraestructuras (responsables de gestionar la infraestructura f铆sica), y los proveedores de servicios (responsables de los protocolos de red y de ofrecer los servicios finales). De esta forma los proveedores de servicios podr谩n solicitar y gestionar en funci贸n de las necesitados redes 贸pticas virtuales dedicadas y espec铆ficas por las aplicaciones. Las tecnolog铆as de virtualizaci贸n de redes 贸pticas virtuales permiten la partici贸n y composici贸n de infraestructura de red (nodos y enlaces 贸pticos) en recursos virtuales independientes que adoptan las mismas funcionalidades que los recursos f铆sicos. La composici贸n de estos recursos virtuales (nodos y enlaces 贸pticos virtuales) permite el despliegue de m煤ltiples VONs. Una VON no s贸lo est谩 compuesta por un plan de transporte virtual, sino tambi茅n por un plan de control virtual, con el objetivo de incorporar las funcionalidades necesarias a la VON (provisi贸n de conexiones autom谩ticas y recuperaci贸n (protecci贸n/restauraci贸n), ingenier铆a de tr谩fico, etc.). Esta tesis se centra en la virtualizaci贸n de redes 贸pticas con tres objetivos principales. El primer objetivo consiste en el dise帽o, implementaci贸n y evaluaci贸n de la arquitectura y los protocolos e interfaces necesarios por la virtualizaci贸n de redes encaminadas a trav茅s de la longitud de ola y controladas por GMPLS. Tambi茅n incluye la introducci贸n de un gestor de recursos para desplegar redes 贸pticas virtuales de forma din谩mica. La introducci贸n de este gestor de recursos implica la necesidad de una gesti贸n de los recursos virtuales y de algoritmos de asignaci贸n de recursos para la utilizaci贸n 贸ptima de los recursos f铆sicos. Adem谩s el gestor de recursos tiene que ser capaz del despliegue de los recursos asignados, incluyendo un plan de control GMPLS virtual independiente para cada VON desplegada. Finalmente, este objetivo incluye la introducci贸n de mecanismos de virtualizaci贸n para redes el谩sticas 贸pticas (EON, en ingl茅s). El segundo objetivo es el dise帽o, la implementaci贸n y la evaluaci贸n experimental de una arquitectura de sistema para ofrecer redes MPLS-TP virtuales controladas por GMPLS sobre una infraestructura WSON compartida. Por eso, esta tesis tambi茅n se centra en el dise帽o y desarrollo de un nodo MPLS-TP que ha sido desplegado al demostrador ADRENALINE, en el CTTC. Finalmente, el tercer objetivo es la composici贸n de m煤ltiples redes 贸pticas virtuales en dominios de control heterog茅neos (GMPLS y OpenFlow). Un gestor de recursos multi-dominio ha sido dise帽ado, implementado y evaluado

    Intelligent Network Infrastructures: New Functional Perspectives on Leveraging Future Internet Services

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    The Internet experience of the 21st century is by far very different from that of the early '80s. The Internet has adapted itself to become what it really is today, a very successful business platform of global scale. As every highly successful technology, the Internet has suffered from a natural process of ossification. Over the last 30 years, the technical solutions adopted to leverage emerging applications can be divided in two categories. First, the addition of new functionalities either patching existing protocols or adding new upper layers. Second, accommodating traffic grow with higher bandwidth links. Unfortunately, this approach is not suitable to provide the proper ground for a wide gamma of new applications. To be deployed, these future Internet applications require from the network layer advanced capabilities that the TCP/IP stack and its derived protocols can not provide by design in a robust, scalable fashion. NGNs (Next Generation Networks) on top of intelligent telecommunication infrastructures are being envisioned to support future Internet Services. This thesis contributes with three proposals to achieve this ambitious goal. The first proposal presents a preliminary architecture to allow NGNs to seamlessly request advanced services from layer 1 transport networks, such as QoS guaranteed point-to-multipoint circuits. This architecture is based on virtualization techniques applied to layer 1 networks, and hides from NGNs all complexities of interdomain provisioning. Moreover, the economic aspects involved were also considered, making the architecture attractive to carriers. The second contribution regards a framework to develop DiffServ-MPLS capable networks based exclusively on open source software and commodity PCs. The developed DiffServ-MPLS flexible software router was designed to allow NGN prototyping, that make use of pseudo virtual circuits and assured QoS as a starting point of development. The third proposal presents a state of the art routing and wavelength assignment algorithm for photonic networks. This algorithm considers physical layer impairments to 100% guarantee the requested QoS profile, even in case of single network failures. A number of novel techniques were applied to offer lower blocking probability when compared with recent proposed algorithms, without impacting on setup delay time

    In-operation planning in flexgrid optical core networks

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    New generation applications, such as cloud computing or video distribution, can run in a telecom cloud infrastructure where the datacenters (DCs) of telecom operators are integrated in their networks thus, increasing connections' dynamicity and resulting in time-varying traffic capacities, which might also entail changes in the traffic direction along the day. As a result, a flexible optical technology able to dynamically set-up variable-capacity connections, such as flexgrid, is needed. Nonetheless, network dynamicity might entail network performance degradation thus, requiring re-optimizing the network while it is in operation. This thesis is devoted to devise new algorithms to solve in-operation network planning problems aiming at enhancing the performance of optical networks and at studying their feasibility in experimental environments. In-operation network planning requires from an architecture enabling the deployment of algorithms that must be solved in stringent times. That architecture can be based on a Path Computation Element (PCE) or a Software Defined Networks controller. In this thesis, we assume the former split in a front-end PCE, in charge of provisioning paths and handling network events, and a specialized planning tool in the form of a back-end PCE responsible for solving in-operation planning problems. After the architecture to support in-operation planning is assessed, we focus on studying the following applications: 1) Spectrum fragmentation is one of the most important problems in optical networks. To alleviate it to some extent without traffic disruption, we propose a hitless spectrum defragmentation strategy. 2) Each connection affected by a failure can be recovered using multiple paths to increase traffic restorability at the cost of poor resource utilization. We propose re-optimizing the network after repairing the failure to aggregate and reroute those connections to release spectral resources. 3) We study two approaches to provide multicast services: establishing a point-to-multipoint connections at the optical layer and using multi-purpose virtual network topologies (VNT) to serve both unicast and multicast connectivity requests. 4) The telecom cloud infrastructure, enables placing contents closer to the users. Based on it, we propose a hierarchical content distribution architecture where VNTs permanently interconnect core DCs and metro DCs periodically synchronize contents to the core DCs. 5) When the capacity of the optical backbone network becomes exhausted, we propose using a planning tool with access to inventory and operation databases to periodically decide the equipment and connectivity to be installed at the minimum cost reducing capacity overprovisioning. 6) In multi-domain multi-operator scenarios, a broker on top of the optical domains can provision multi-domain connections. We propose performing intra-domain spectrum defragmentation when no contiguous spectrum can be found for a new connection request. 7) Packet nodes belonging to a VNT can collect and send incoming traffic monitoring data to a big data repository. We propose using the collected data to predict next period traffic and to adapt the VNT to future conditions. The methodology followed in this thesis consists in proposing a problem statement and/or a mathematical formulation for the problems identified and then, devising algorithms for solving them. Those algorithms are simulated and then, they are experimentally assessed in real test-beds. This thesis demonstrates the feasibility of performing in-operation planning in optical networks, shows that it enhances the performance of the network and validates the feasibility of its deployment in real networks. It shall be mentioned that part of the work reported in this thesis has been done within the framework of several research projects, namely IDEALIST (FP7-ICT-2011-8) and GEANT (238875) funded by the EC and SYNERGY (TEC2014-59995-R) funded by the MINECO.Les aplicacions de nova generaci贸, com ara el cloud computing o la distribuci贸 de v铆deo, es poden executar a infraestructures de telecom cloud (TCI) on operadors integren els seus datacenters (DC) a les seves xarxes. Aquestes aplicacions fan que incrementi tant la dinamicitat de les connexions, com la variabilitat de les seves capacitats en el temps, arribant a canviar de direcci贸 al llarg del dia. Llavors, cal disposar de tecnologies 貌ptiques flexibles, tals com flexgrid, que suportin aquesta dinamicitat a les connexions. Aquesta dinamicitat pot degradar el rendiment de la xarxa, obligant a re-optimitzar-la mentre 茅s en operaci贸. Aquesta tesis est脿 dedicada a idear nous algorismes per a resoldre problemes de planificaci贸 sobre xarxes en operaci贸 (in-operation network planning) per millorar el rendiment de les xarxes 貌ptiques i a estudiar la seva factibilitat en entorns experimentals. Aquests problemes requereixen d鈥檜na arquitectura que permeti desplegar algorismes que donin solucions en temps restrictius. L鈥檃rquitectura pot estar basada en un Element de Computaci贸 de Rutes (PCE) o en un controlador de Xarxes Definides per Software. En aquesta tesis, assumim un PCE principal encarregat d鈥檃provisionar rutes i gestionar esdeveniments de la xarxa, i una eina de planificaci贸 especialitzada en forma de PCE de suport per resoldre problemes d鈥檌n-operation planning. Un cop validada l鈥檃rquitectura que dona suport a in-operation planning, estudiarem les seg眉ents aplicacions: 1) La fragmentaci贸 d鈥檈spectre 茅s un dels principals problemes a les xarxes 貌ptiques. Proposem reduir-la en certa mesura, fent servir una estrat猫gia que no afecta al tr脿fic durant la desfragmentaci贸. 2) Cada connexi贸 afectada per una fallada pot ser recuperada fent servir m煤ltiples rutes incrementant la restaurabilitat de la xarxa, tot i empitjorar-ne la utilitzaci贸 de recursos. Proposem re-optimitzar la xarxa despr茅s de reparar una fallada per agregar i re-enrutar aquestes connexions tractant d鈥檃lliberar recursos espectrals. 3) Estudiem dues solucions per aprovisionar serveis multicast: establir connexions punt-a-multipunt sobre la xarxa 貌ptica i utilitzar Virtual Network Topologies (VNT) multi-prop貌sit per a servir peticions de connectivitat tant unicast com multicast. 4) La TCI permet mantenir els continguts a prop dels usuaris. Proposem una arquitectura jer脿rquica de distribuci贸 de continguts basada en la TCI, on els DC principals s鈥檌nterconnecten per mitj脿 de VNTs permanents i els DCs metropolitans peri貌dicament sincronitzen continguts amb els principals. 5) Quan la capacitat de la xarxa 貌ptica s鈥檈xhaureix, proposem utilitzar una eina de planificaci贸 amb acc茅s a bases de dades d鈥檌nventari i operacionals per decidir peri貌dicament l鈥檈quipament i connectivitats a instal路lar al m铆nim cost i reduir el sobre-aprovisionament de capacitat. 6) En entorns multi-domini multi-operador, un broker per sobre dels dominis 貌ptics pot aprovisionar connexions multi-domini. Proposem aplicar desfragmentaci贸 d鈥檈spectre intra-domini quan no es pot trobar espectre contigu per a noves peticions de connexi贸. 7) Els nodes d鈥檜na VNT poden recollir i enviar informaci贸 de monitoritzaci贸 de tr脿fic entrant a un repositori de big data. Proposem utilitzar aquesta informaci贸 per adaptar la VNT per a futures condicions. La metodologia que hem seguit en aquesta tesis consisteix en formalitzar matem脿ticament els problemes un cop aquests son identificats i, despr茅s, idear algorismes per a resoldre鈥檒s. Aquests algorismes son simulats i finalment validats experimentalment en entorns reals. Aquesta tesis demostra la factibilitat d鈥檌mplementar mecanismes d鈥檌n-operation planning en xarxes 貌ptiques, mostra els beneficis que aquests aporten i valida la seva aplicabilitat en xarxes reals. Part del treball presentat en aquesta tesis ha estat dut a terme en el marc dels projectes de recerca IDEALIST (FP7-ICT-2011-8) i GEANT (238875), finan莽ats per la CE, i SYNERGY (TEC2014-59995-R), finan莽at per el MINECO.Postprint (published version

    Traffic engineering in dynamic optical networks

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    Traffic Engineering (TE) refers to all the techniques a Service Provider employs to improve the efficiency and reliability of network operations. In IP over Optical (IPO) networks, traffic coming from upper layers is carried over the logical topology defined by the set of established lightpaths. Within this framework then, TE techniques allow to optimize the configuration of optical resources with respect to an highly dynamic traffic demand. TE can be performed with two main methods: if the demand is known only in terms of an aggregated traffic matrix, the problem of automatically updating the configuration of an optical network to accommodate traffic changes is called Virtual Topology Reconfiguration (VTR). If instead the traffic demand is known in terms of data-level connection requests with sub-wavelength granularity, arriving dynamically from some source node to any destination node, the problem is called Dynamic Traffic Grooming (DTG). In this dissertation new VTR algorithms for load balancing in optical networks based on Local Search (LS) techniques are presented. The main advantage of using LS is the minimization of network disruption, since the reconfiguration involves only a small part of the network. A comparison between the proposed schemes and the optimal solutions found via an ILP solver shows calculation time savings for comparable results of network congestion. A similar load balancing technique has been applied to alleviate congestion in an MPLS network, based on the efficient rerouting of Label-Switched Paths (LSP) from the most congested links to allow a better usage of network resources. Many algorithms have been developed to deal with DTG in IPO networks, where most of the attention is focused on optimizing the physical resources utilization by considering specific constraints on the optical node architecture, while very few attention has been put so far on the Quality of Service (QoS) guarantees for the carried traffic. In this thesis a novel Traffic Engineering scheme is proposed to guarantee QoS from both the viewpoint of service differentiation and transmission quality. Another contribution in this thesis is a formal framework for the definition of dynamic grooming policies in IPO networks. The framework is then specialized for an overlay architecture, where the control plane of the IP and optical level are separated, and no information is shared between the two. A family of grooming policies based on constraints on the number of hops and on the bandwidth sharing degree at the IP level is defined, and its performance analyzed in both regular and irregular topologies. While most of the literature on DTG problem implicitly considers the grooming of low-speed connections onto optical channels using a TDM approach, the proposed grooming policies are evaluated here by considering a realistic traffic model which consider a Dynamic Statistical Multiplexing (DSM) approach, i.e. a single wavelength channel is shared between multiple IP elastic traffic flows

    End-to-end quality of service provisioning in multilayer and multidomain environments

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    Tesis doctoral in茅dita. Universidad Aut贸noma de Madrid, Escuela Polit茅cnica Superior, marzo de 200

    Architectures and protocols for sub-wavelength optical networks: contributions to connectionless and connection-oriented data transport

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    La r脿pida evoluci贸 d鈥橧nternet i l鈥櫭爉plia gamma de noves aplicacions (per exemple, multim猫dia, videoconfer猫ncia, jocs en l铆nia, etc.) ha fomentat canvis revolucionaris en la manera com ens comuniquem. A m茅s, algunes d鈥檃questes aplicacions demanden grans quantitats de recursos d鈥檃mple de banda amb diversos requeriments de qualitat de servei (QoS). El desenvolupament de la multiplexaci贸 per divisi贸 de longitud d鈥檕na (WDM) en els anys noranta va fer molt rendible la disponibilitat d鈥檃mple de banda. Avui dia, les tecnologies de commutaci贸 貌ptica de circuits s贸n predominants en el nucli de la xarxa, les quals permeten la configuraci贸 de canals (lightpaths) a trav茅s de la xarxa. No obstant aix貌, la granularitat d鈥檃quests canals ocupa tota la longitud d鈥檕na, el que fa que siguin ineficients per a proveir canals de menor ample de banda (sub-longitud d鈥檕na). Segons la comunitat cient铆fica, 茅s necessari augmentar la transpar猫ncia dels protocols, aix铆 com millorar l鈥檃provisionament d鈥檃mple de banda de forma din脿mica. Per tal de fer aix貌 realitat, 茅s necessari desenvolupar noves arquitectures. La commutaci贸 貌ptica de r脿fegues i de paquets (OBS/OPS), s贸n dues de les tecnologies proposades. Aquesta tesi contribueix amb tres arquitectures de xarxa destinades a millorar el transport de dades sub-longitud d鈥檕na. En primer lloc, aprofundim en la naturalesa sense connexi贸 en OBS. En aquest cas, la xarxa incrementa el seu dinamisme a causa de les transmissions a r脿fega. A m茅s, les col路lisions entre r脿fegues degraden el rendiment de la xarxa fins i tot a c脿rregues molt baixes. Per fer front a aquestes col路lisions, es proposa un esquema de resoluci贸 de col路lisions pro actiu basat en un algorisme d鈥檈ncaminament i assignaci贸 de longitud d鈥檕na (RWA) que balanceja de forma autom脿tica i distribu茂da la c脿rrega en la xarxa. En aquest protocol, el RWA i la transmissi贸 de r脿fegues es basen en l鈥檈xplotaci贸 i exploraci贸 de regles de commutaci贸 que incorporen informaci贸 sobre contencions i encaminament. Per donar suport a aquesta arquitectura, s鈥檜tilitzen dos tipus de paquets de control per a l鈥檈ncaminament de les r脿fegues i l鈥檃ctualitzaci贸 de les regles de commutaci贸, respectivament. Per analitzar els beneficis del nou algorisme, s鈥檜tilitzen quatre topologies de xarxa diferents. Els resultats indiquen que el m猫tode proposat millora en diferents marges la resta d鈥檃lgorismes RWA en funci贸 de la topologia i sense penalitzar altres par脿metres com el retard extrem a extrem. La segona contribuci贸 proposa una arquitectura h铆brida sense i orientada a connexi贸 sobre la base d鈥檜n protocol de control d鈥檃cc茅s al medi (MAC) per a xarxes OBS (DAOBS). El MAC ofereix dos m猫todes d鈥檃cc茅s: arbitratge de cua (QA) per a la transmissi贸 de r脿fegues sense connexi贸, i pre-arbitratge (PA) per serveis TDM orientats a connexi贸. Aquesta arquitectura permet una 脿mplia gamma d鈥檃plicacions sensibles al retard i al bloqueig. Els resultats avaluats a trav茅s de simulacions mostren que en l鈥檃cc茅s QA, les r脿fegues de m茅s alta prioritat tenen garantides zero p猫rdues i lat猫ncies d鈥檃cc茅s molt baixes. Pel que fa a l鈥檃cc茅s PA, es reporta que la duplicaci贸 de la c脿rrega TDM augmenta en m茅s d鈥檜n ordre la probabilitat de bloqueig, per貌 sense afectar en la mateixa mesura les r脿fegues sense connexi贸. En aquest cap铆tol tamb茅 es tracten dos dels problemes relacionats amb l鈥檃rquitectura DAOBS i el seu funcionament. En primer lloc, es proposa un model matem脿tic per aproximar el retard d鈥檃cc茅s inferior i superior com a conseq眉猫ncia de l鈥檃cc茅s QA. En segon lloc, es formula matem脿ticament la generaci贸 i optimitzaci贸 de les topologies virtuals que suporten el protocol per a l鈥檈scenari amb tr脿fic est脿tic. Finalment, l鈥櫭簂tima contribuci贸 explora els beneficis d鈥檜na arquitectura de xarxa 貌ptica per temps compartit (TSON) basada en elements de c脿lcul de camins (PCE) centralitzats per tal d鈥檈vitar col路lisions en la xarxa. Aquesta arquitectura permet garantir l鈥檃provisionament orientat a connexi贸 de canals sub-longitud d鈥檕na. En aquest cap铆tol proposem i simulem tres arquitectures GMPLS/PCE/TSON. A causa del enfocament centralitzat, el rendiment de la xarxa dep猫n en gran mesura de l鈥檃ssignaci贸 i aprovisionament de les connexions. Amb aquesta finalitat, es proposen diferents algorismes d鈥檃ssignaci贸 de ranures temporals i es comparen amb les corresponents formulacions de programaci贸 lineal (ILP) per al cas est脿tic. Per al cas de tr脿fic din脿mic, proposem i avaluem mitjan莽ant simulaci贸 diferents heur铆stiques. Els resultats mostren els beneficis de proporcionar flexibilitat en els dominis temporal i freq眉encial a l鈥檋ora d鈥檃ssignar les ranures temporals.The rapid evolving Internet and the broad range of new data applications (e.g., multimedia, video-conference, online gaming, etc.) is fostering revolutionary changes in the way we communicate. In addition, some of these applications demand for unprecedented amounts of bandwidth resources with diverse quality of service (QoS). The development of wavelength division multiplexing (WDM) in the 90's made very cost-effective the availability of bandwidth. Nowadays, optical circuit switching technologies are predominant in the core enabling the set up of lightpaths across the network. However, full-wavelength lightpath granularity is too coarse, which results to be inefficient for provisioning sub-wavelength channels. As remarked by the research community, an open issue in optical networking is increasing the protocol transparency as well as provisioning true dynamic bandwidth allocation at the network level. To this end, new architectures are required. Optical burst/packet switching (OBS/OPS) are two such proposed technologies under investigation. This thesis contributes with three network architectures which aim at improving the sub-wavelength data transport from different perspectives. First, we gain insight into the connectionless nature of OBS. Here, the network dynamics are increased due to the short-lived burst transmissions. Moreover, burst contentions degrade the performance even at very low loads. To cope with them, we propose a proactive resolution scheme by means of a distributed auto load-balancing routing and wavelength assignment (RWA) algorithm for wavelength-continuity constraint networks. In this protocol, the RWA and burst forwarding is based on the exploitation and exploration of switching rule concentration values that incorporate contention and forwarding desirability information. To support such architecture, forward and backward control packets are used in the burst forwarding and updating rules, respectively. In order to analyze the benefits of the new algorithm, four different network topologies are used. Results indicate that the proposed method outperforms the rest of tested RWA algorithms at various margins depending on the topology without penalizing other parameters such as end-to-end delay. The second contribution proposes a hybrid connectionless and connection-oriented architecture based on a medium access control (MAC) protocol for OBS networks (DAOBS). The MAC provides two main access mechanisms: queue arbitrated (QA) for connectionless bursts and pre-arbitrated (PA) for TDM connection-oriented services. Such an architecture allows for a broad range of delay-sensitive applications or guaranteed services. Results evaluated through simulations show that in the QA access mode highest priority bursts are guaranteed zero losses and very low access latencies. Regarding the PA mode, we report that doubling the offered TDM traffic load increases in more than one order their connection blocking, slightly affecting the blocking of other connectionless bursts. In this chapter, we also tackle two of the issues related with the DAOBS architecture and its operation. Firstly, we model mathematically the lower and upper approximations of the access delay as a consequence of the connectionless queue arbitrated access. Secondly, we formulate the generation of the virtual light-tree overlay topology for the static traffic case.Postprint (published version
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