Dissertations / Theses on the topic 'Multi-protocol Label Switching'

The world has emerged as a global village. Internet has brought an amazing change in the era of modern communications. Demand for multimedia applications and an ever increasing amount of VoIP traffic have increased data rate and bandwidth requirements. It has become a big chal-lenge to provide best quality applications. Traffic engineers are working hard over Internet Protocol (IP) and Routing Protocols (RPs) in order to cope with this challenge. IP networks have offered these services efficiently until now, but there are several issues with IP routing that affect the Quality of Service (QoS). Multi-Protocol Label Switching (MPLS) has emerged as an agile technology which promises effective security together with high speed data delivery. MPLS networks use switching instead of conventional routing. MPLS doesn’t replace existing IP networks, but guarantees instead better QoS in existing IP networks as well as future routing technologies, providing thus a suitable environment for Traffic Engineering (TE). The Class of Service (CoS) architecture provided by MPLS can easily be coordinated with IP QoS mecha-nisms. Traffic can be switched based on resource utilization and network performance instead of using static routing techniques such as selecting a path with least cost, optimizing thus the MPLS network for heavy application at desired quality.
Världen har blivit en global by. Internet har inneburit en fantastisk förändring i en tid präglad av modern kommunikation. Efterfrågan på multimediaapplikationer och en allt större mängd VoIP-trafik har ökat datahastighet och krav på bandbredd. Det har blivit en stor utmaning att ge bästa kvalitet ansökningar. Trafiken tekniker arbetar hårt over Internet Protocol (IP) och routingprotokoll (RPS) för att klara av denna utmaning. IP-nät har erbjudit dessa tjänster på ett effektivt fram tills nu, men det finns flera problem med IP-routing som påverkar Quality of Service (QoS). Multi-Protocol Label Switching (MPLS) har utvecklats till en flexibel teknik som utlovar effektiv säkerhet tillsammans med hög hastighet leverans. MPLS-nätverk används byte istället för konventionella routing. MPLS ersätter inte de befintliga IP-nät, utan garantier i stället bättre QoS i befintliga IP-nät samt framtida routing-teknik, vilket har en lämplig miljö för trafikteknik (TE). Den klass som (COS) arkitektur som MPLS kan enkelt styras med IP QoS meka-nismer. Trafiken kan kopplas grundas på resursutnyttjande och nätverksprestanda istället för att använda statisk routing tekniker som att välja en väg med lägsta kostnad, vilket optimerar därmed MPLS nät för tunga ansökan till önskad kvalitet.

Den här rapporten beskriver tekniken Multi Protocol Label Switching. Fokus ligger på hur information överförs och vilka vitala delar det är som sammanbinder ett fullt fungerande MPLS nätverk. Syftet bakom arbetet är att bilda sig en förståelse för i vilket sammanhang det är lämpligt att använda sig av tekniken. Det är även att utforska på vilket sätt MPLS är ett förstahandsalternativ i förhållande till övriga lösningar.     Rapporten innehåller information om hur kommunikationen sker mellan olika kopplingspunkter och hur det på så vis kan dra nytta av de fördelar som tillkommer med tekniken. Noggrant utvalda och relevanta frågor ställs för att beskriva det som gör MPLS unikt. Generellt handlar det om förmedling av etiketter till trafikreglerade lösningar, en teknologi som börjat ta mer plats och mogna allt mer med åren.
This report describes the technology Multiprotocol Label Switching. The focus will be on how information is transmitted and what vital parts it is linking a fully functional MPLS network. The purpose behind all this work is to gain an understanding of the context in which it is necessary to use the technology. It is also to investigate how MPLS is a first-hand options relative to other solutions. The report contains information about how the communication takes place between different access points and how they can take advantage of the benefits that come with the technology. Carefully selected and relevant questions are asked to describe what makes MPLS unique. Generally, it is about the transportation of labels to controlled traffic solutions, a technology that´s started to take up more space and becoming more mature over the years.

Multi-Protocol Label Switching (MPLS) is a technique that can be used to improve the performance of a computer communication network. By use of MPLS, data packets can be switched on the basis of labels rather than routed on the basis of destination address. MPLS supports different features like QoS, traffic engineering and VPNs etc.

This thesis evaluates the working and performance of MPLS and its support for Quality of Service. QoS is required in the network when real time traffic is transported.

In this thesis it is described, how QoS guarantees are assigned to the IP packets and how MPLS QoS environment differs from the traditional IP routing environment. MPLS QoS works as the IP QoS, but MPLS QoS enhances the capability of network as compared to the IP QoS based network.

The thesis studies the use of MPLS in an integrated environment with DiffServ QoS model and also implements MPLS QoS in a Lab environment to compare MPLS QoS with IP QoS. Real time traffic faces longer delays in IP QoS based networks. MPLS QoS reduces the delays in real time traffic transmission.

The study results and the practical implementations show that MPLS QoS provide much better results than simple IP QoS.

This thesis presents the combination of MPLS-TP protocol with an integrated hybridnetwork, the Opmigua network. It is presented that the MPLS-TP protocol is applicableand follows all the requirements to be compatible with an Opmigua network. Differentnetwork scenarios, combining packet and circuit switching properties with MPLS-TPlabels, are presented. At the beginning of this thesis, are provided the characteristics and requirements of MPLS-TP protocol which the standardization of this is on going. Furthermore, it is explained how the MPLS-TP management and the forwarding plane work. Some references are also given not only to OAM mechanisms, but also to control plane that the MPLS-TP uses. We use both, global and local significance MPLS-TP labels for distinguishing theGuaranteed Service Traffic (GST) packets from Statistical Multiplexing (SM) packets.Using this method, we have concluded some results, as it concerns GST and SMtraffic. GST packets take a global significance label value until to reach the destination node. On the other hand, SM packets take local significance labels for each path into an Opmigua network which follow Optical Packet Switch (OPS) networks. We have proposed a new method for differentiation of packets from low to high priority using extension headers of Internet Protocol v6 either Destination Options Header(DOH) or MPLS-TP as an extension header. The result that we have derived is highand low priority packets are differentiated at ingress Opmigua network which GST packets take global significance MPLS-TP label following Optical Cross Connect (OXC) network and SM packets change per each Label Switched Path (LSP) local significance MPLS-TP labels until to reach the destination. Finally, two MPLS-TP path protection schemes, facility bypass and restoration usingdetours were combined with Opmigua network to provide failures for both, GuaranteedService Traffic (GST) packets and Statistical Multiplexing (SM) packets.

Traffic Engineering (TE) is the stage which deals with geometric design planning and traffic operation of networks, network devices and relationship of routers for the transportation of data. TE is that feature of network engineering which concentrate on problems of performance optimization of operational networks. It involves techniques and application of knowledge to gain performance objectives, which includes movement of data through network, reliability, planning of network capacity and efficient use of network resources. This thesis addresses the problems of traffic engineering and suggests a solution by using the concept of Multi-Protocol Label Switching (MPLS). We have done simulation in Matlab environment to compare the performance of MPLS against the IP network in a simulated environment. MPLS is a modern technique for forwarding network data. It broadens routing according to path controlling and packet forwarding. In this thesis MPLS is computed on the basis of its performance, efficiency for sending data from source to destination. A MATLAB based simulation tool is developed to compare MPLS with IP network in a simulated environment. The results show the performance of MPLS network in comparison of IP network.
YASSAR AZIZ, +46 73 9135296 MUHAMMAD NAEEM ASLAM +46 70 4918985

Includes bibliographical references (leaves 55-57).
The challenge of parking management has increasingly posed the need for smart solutions. Motorists in today's busy world seek the best option in locating available parking points. The need for an efficient parking system stems from increased congestion, motor vehicle pollution, driver frustration and fatigue to mention but a few. This study was conducted at a time when the world was experiencing a financial crisis and more than ever motorists needed intelligent parking systems to reduce the cost of gas spent driving around to find parking. Indeed, the time spent driving around would be beneficial if used to do work that would put one at an advantage in the credit recession. The study was also conducted at a time when South Africa was preparing to host the 2010 soccer world cup. In the preparation to manage motor vehicle congestion, this study was a viable solution to manage the expected challenge of parking. This study presents the design and illustrates the performance of an intelligent parking system based on an integrated architecture where (1) Wireless Sensor networks (WSNs) using Small Programmable Object Technology (SPOT) motes are launched into parking places to monitor the activity of the parking area through light intensity sensing and (2) the sensed information is gathered and channeled through a gateway into databases used for parking space visualization and information dissemination over the World Wide Web technology and mobile devices via a Multi Protocol label Switching (MPLS) network. Using an illustrative simulation model of a small parking system built around a new generation of SUNspot motes, the study demonstrates how a real life smart parking iv system can be deployed to benefit motorists in today's busy World and serves as a foundation to future work on how this emerging generation of motes can be used to provide better ways of finding parking.

The ongoing development of new and demanding Internet applications requires the Internet to deliver better service levels that are significantly better than the best effort service that the Internet currently provides and was built for. These improved service levels include guaranteed delays, jitter and bandwidth. Through extensive research into Quality of Service and Differentiated Service (DiffServ) it has become possible to provide guaranteed services, however this turns out to be inadequate without the application of Traffic Engineering methodologies and principles. Traffic Engineering is an integral part of network operation. Its major goal is to deliver the best performance from an existing service provider's network resources and, at the same time, to enhance a customers' view of network performance. In this thesis, several different traffic engineering methods for optimising the operation of native IP and IP networks employing MPLS are proposed. A feature of these new methods is their fast run times and this opens the way to making them suitable for application in an online traffic engineering environment. For native IP networks running shortest path based routing protocols, we show that an LP-based optimisation based on the well known multi-commodity flow problem can be effective in removing network congestion. Having realised that Internet service providers are now moving towards migrating their networks to the use of MPLS, we have also formulated optimisation methods to traffic engineer MPLS networks by selecting suitable routing paths and utilising the feature of explicit routing contained in MPLS. Although MPLS is capable of delivering traffic engineering across different classes of traffic, network operators still prefer to rely on the proven and simple IP based routing protocols for best effort traffic and only use MPLS to route traffic requiring special forwarding treatment. Based on this fact, we propose a method that optimises the routing patterns applicable to different classes of traffic based on their bandwidth requirements. A traffic engineering comparison study that evaluates the performance of a neural network-based method for MPLS networks and LP-based weight setting approach for shortest path based networks has been performed using a well-known open source network simulator, called ns2. The comparative evaluation is based upon the packet loss probability. The final chapter of the thesis describes the software development of a network management application called OptiFlow which integrates techniques described in earlier chapters including the LP-based weight setting optimisation methodology; it also uses traffic matrix estimation techniques that are required as input to the weight setting models that have been devised. The motivation for developing OptiFlow was to provide a prototype set of tools that meet the congestion management needs of networking industries (ISPs and telecommunications companies - telcos).

This research is related to computer networks. In this thesis, three main issues are addressed which affect the performance of any computer network: congestion, efficient resources utilization and link failure. Those issues are related to each other in many situations. Many approaches have been suggested to deal with those issues as well as many solutions were applied. Despite all the improvements of the technology and the proposed solutions, those issues continue to be a burden on the system’s performance. This effect is related to the increase of the Quality of Service (QoS) requirements in modern networks. The basic idea of this research is evolving the intelligence of a conventional computer network when dealing with those issues by adding some features of the Software Defined Networking (SDN). This adoption upgrades the conventional computer network system to be more dynamic and higher self-organizing when dealing with those issues. This idea is applied on a system represented by a computer network that uses the Open Shortest Path First (OSPF) routing protocol. The first improvement deals with the distribution of Internet Protocol (IP) routed flows. The second improvement deals with tunnel establishment that serves Multi-Protocol Label Switching (MPLS) routed flows and the third improvement deals with bandwidth reservation when applying network restoration represented by Fast Re-route (FRR) mechanism to sooth the effect of link failure in OSPF/MPLS routed network. This idea is also applied on another system that uses the Enhanced Interior Gateway Routing Protocol (EIGRP) to improve the performance of its routing algorithm. Adopting the SDN notion is achieved by adding an intelligent controller to the system and creating a dialog of messages between the controller and the conventional routers. This requires upgrading the routers to respond to the new modified system. Our proposed approaches are presented with simulations of different configurations which produce fine results.

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.

Die schichtenübergreifende Steuerung von Multi-Layer Netzen ermöglicht die Realisierung fortgeschrittener Netzarchitekturen sowie neuartiger Konzepte zur Steigerung der Ausfallsicherheit. Gegenstand dieser Arbeit ist ein neues ressourcensparendes Konzept zur Kompensation von Core-Router-Ausfallen in IP-Netzen. Core-Router-Ausfälle führen zur Abkopplung der an Ihnen angeschlossenen Zugangsrouter vom Netz. Daher werden die Zugangsrouter üblicherweise mit jeweils zwei oder mehreren verschiedenen Core-Routern verbunden (engl.: dual homing) was jedoch eine Verdoppelung der Anschlusskapazität im IP Netz bedingt. Bei dem neuen Verfahren - Dual Homing mit gemeinsam genutzten Router-Ersatzressourcen (engl.: dual homing with shared backup router resources, DH-SBRR) - erfolgt die Zugangsrouter-Anbindung zum einen zu einem Core-Router des IP-Netzes und zum anderen zu einem Netzelement der darunterliegenden Transportschicht. Damit lassen sich Router-Ersatzressourcen, die im IP-Netz an beliebigen Stellen vorgehalten werden können, uber das Transportnetz an die Stelle eines ausgefallenen Core-Routers schalten. Die Steuerung dieser Ersatzschaltung geschieht über eine schichten übergreifende, d.h. das Transportnetz- und IP-Netz umfassende Control-Plane - beispielsweise auf Basis von GMPLS. Da beim Umschalten der Routerressourcen auch aktuelle Zustände (bspw. Routing-Tabellen) auf die Router-Ersatzressourcen mit übertragen werden müssen, beinhaltet das neue Verfahren auch Konzepte zur Router-Virtualisierung. Zum Vergleich und zur Bewertung der Leistungsfähigkeit des neuen DH-SBRR Verfahrens werden in der Arbeit verschiedene Zugangsrouter-Homing-Varianten hinsichtlich Netz-Kosten, Netz-Verfügbarkeit, Recovery-Zeit und Netz-Energieverbrauch gegenübergestellt. Als Multi-Layer Netzszenarien werden zum einen IP über WDM und zum anderen IP über OTN (ODU) betrachtet. Zur Bestimmung der minimalen Netz-Kosten ist ein generisches Multi-Layer Netzoptimierungsmodell entwickelt worden, welches bei unterschiedlichen Homing-Architekturen angewendet werden kann. Neben dem Optimierungsmodell zur Netzkostenminimierung wird auch eine Modellvariante zur Minimierung des Energieverbrauchs vorgestellt. Um die Rechenzeit für die Lösung der Optimierungsprobleme zu verringern und damit auch größere Netzszenarien untersuchen zu können bedarf es heuristischer Lösungsverfahren. Im Rahmen der Arbeit ist daher eine neue speziell auf die Multilayer-Optimierungsprobleme zugeschnittene Lösungsheuristik entwickelt worden. Aus der Netzkosten-Optimierung ergibt sich, dass durch den Einsatz von DH-SBBR signifikante Kosteneinsparungen im Vergleich zu herkömmlichen Homing-Architekturen realisiert werden können. Änderungen der Verkehrslast, der Kosten der IP-Netzelemente oder der Netztopologie haben keinen signifikanten Einfluss auf dieses Ergebnis. Neben dem Kosten- und Energieeinsparungspotential sind auch die Auswirkungen auf die Netz-Verfügbarkeit und die Recovery-Zeit untersucht worden. Für die Ende-zu-Ende Verfügbarkeit bei Anwendung der verschiedenen Homing-Architekturen Können untere Grenzwerte angegeben werden. Zur Bestimmung der Recovery-Zeit bei Einsatz von DH-SBRR ist ein eigenes analytisches Berechnungsmodell entwickelt und evaluiert worden. Damit kann das DH-SBRR Verfahren zur Einhaltung vorgegebener Recovery-Zeiten (wie sie für bspw. Für bestimmte Dienste gefordert werden) entsprechend parametriert werden
The emergence of multi-layer networking capabilities opens the path for the development of advanced network architectures and resilience concepts. In this dissertation we propose a novel resource-efficient homing scheme: dual homing with shared backup router resources. The proposed scheme realizes shared router-level redundancy, enabled by the emergence of control plane architectures such as generalized multi-protocol label switching. Additionally, virtualization schemes complement the proposed architecture. Different homing architectures are examined and compared under the prism of cost, availability, recovery time and energy efficiency. Multiple network layers are considered in Internet protocol over wavelength division multiplexing as well as Internet protocol over optical data unit settings - leading to the development of multi-layer optimization techniques. A generic multi-layer network design mathematical model, which can be applied to different homing architecture considerations, is developed. The optimization objective can be adapted to either minimizing the cost for network equipment or the power consumption of the network. In order to address potential issues with regard to computational complexity, we develop a novel heuristic approach specifically targeting the proposed architecture. It is shown that significant cost savings can be achieved - even under extreme changes in the traffic demand volume, in the cost for different types of network equipment, as well as in the network topology characteristics. In order to evaluate occurring tradeoffs in terms of performance, we study the effects on availability and recovery time. We proceed to derive lower bounds on end-to-end availability for the different homing architectures. Additionally, an analytical recovery time model is developed and evaluated. We investigate how service-imposed maximum outage requirements have a direct effect on the setting of the proposed architecture

Thesis (MSc)--Stellenbosch University, 2003.
ENGLISH ABSTRACT: The Internet has experienced tremendous growth in the last three decades and has emerged as a platform to carryall forms of communications including voice, video and data. Along with this growth came the urgency for quality of service (QoS) controls in IP networks as different types of traffics have different service requirements. Although the IP protocol is able to scale to very large networks, it does not provide sufficient functionality for traffic engineering in order to enable QoS control. Multi-protocol label switching (MPLS) is a new routing technology that enhances IP with some QoS concepts from ATM and uses relatively simple packet forwarding mechanisms. MPLS has the ability to perform traffic engineering and QoS control by routing traffic flowson virtual connections called label switched paths (LSPs) which are assigned capacity. A large portion of the traffic carried on the Internet consists of data traffic in the form of TCP traffic. This thesis investigates several TCP models to find the ones most suitable to represent TCP traffic in MPLS networks. The models consist of three types. The first type models a single TCP source and the second type models a fixed number of TCP sources. The third type models an infinite number of TCP sources. The models were evaluated by comparing their throughput predictions and results obtained from simulation experiments that were done with the widely-used simulator ns. We also present a simple derivation of the 1/,;e law for the TCP congestion window size where e is the packet loss probability.
AFRIKAANSE OPSOMMING:In die afgelope drie dekades het die Internet beduidende groei ervaar, soveel so dat dit ontluik het as 'n medium om alle tipes van moderne kommunikasies te hanteer insluitend telefoon, video en data. Hierdie groei het gepaard gegaan met die behoefte na diensvlak (QoS) meganismes in IP netwerke aangesien verskillende tipe kommunikasies verskillende diens vereistes het. Alhoewel die IP protokol skalleerbaar is tot baie groot netwerke, voorsien dit nie voldoende funksionaliteit om QoS beheer toe te pas nie. "Multi-protocol label switching" (MPLS) is 'n nuwe roeterings tegnologie wat IP aanvul met QoS konsepte van ATM en dit maak gebruik van relatief eenvoudige pakkie versendings-meganismes. MPLS het die vermoe om netwerk-verkeer reeling en QoS beheer toe te pas deur verkeers-strome te roeteer op virtuele roetes genaamd "label switched paths" (LSPs) aan wie kapasiteit toegeken is. 'n Beduidende gedeelte van Internet-verkeer bestaan uit TCP-verkeer. Hierdie tesis ondersoek verskillende modelle van TCP om die te vind wat die mees geskik is om TCP verkeer in MPLS netwerke te verteenwoordig. Drie tipes modelle is ondersoek. Die eerste tipe moduleer 'n enkele TCP verkeersbron en die tweede tipe moduleer 'n vasgestelde aantal TCP verkeersbronne. Die derde tipe moduleer 'n oneindige aantal verkeersbronne. Die modelle is geevalueer deur hul voorspellings van die tempo van data transmissie te vergelyk met resultate van simulasies. Die simulasies is gedoen met die veelgebruikte simulator ns. Hierdie tesis bevat ook 'n eenvoudige afleiding vir die 1/,;e wet vir die TCP oorlading venster grootte met e die verlies waarskeinlikheid van 'n netwerk pakkie.

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The advent of grid computing made possible to access distributed resources, even when they are geographically spread or belong to different organizations. The most used environment for accessing these distributed resources is the Internet, a worldwide computer network based in TCP/IP architecture. Grid computing provides the infrastructure necessary for managing and communicating with the resources offered by different organizations. These organizations are also known as virtual organizations (VO's). Some of the applications used in these collaborating environments may have minimum requirements by quality of service (QoS). However, the "best effort" service, which is offered by Internet, is not capable to satisfy these QoS requirements. In this case, a different solution is needed, in order to provide guarantees related to the traffic in communication channels. This master thesis aims to apply the concepts of quality of service for networks in grid computing, providing end-to-end quality of service between grid computing applications. In order to achieve this goal, we investigate the use of commutation infrastructure provided by MPLS networks. Using traffic engineering mechanisms for routes determination, we aim to provide better control of data flows, improving the performance of distributed applications in geographically highly spread environments.
O surgimento da computação em grade possibilitou o acesso a recursos distribuídos que podem estar dispersos geograficamente e pertencer a diferentes organizações. O meio mais utilizado para prover acesso a tais recursos é a Internet, uma rede de computadores de alcance mundial baseada na arquitetura TCP/IP. As grades computacionais fornecem a infra-estrutura necessária à comunicação e ao gerenciamento dos recursos fornecidos por estas organizações, também conhecidas por organizações virtuais (VOs) . Algumas das aplicações utilizadas nestes ambientes colaborativos podem possuir requisitos mínimos de qualidade de serviço (QoS). Entretanto, o serviço de melhor esforço oferecido pela Internet não é capaz de satisfazer tais exigências, sendo preciso utilizar outra forma para se obter garantias em relação à capacidade de tráfego dos canais de comunicação. Este trabalho de mestrado objetiva aplicar os conceitos de qualidade de serviço de redes para o provimento de qualidade de serviço fim-a-fim nas comunicações entre aplicações para grades computacionais. Para tanto, investiga o uso da infra-estrutura de comutação provida pelas redes MPLS. Usando mecanismos de determinação de rotas em Engenharia de Tráfego, busca-se prover melhor controle dos fluxos de dados, beneficiando aplicações distribuídas em ambientes de grande dispersão física.

Les réseaux optiques dynamiques et flexibles font partie des scénarios d'évolution des réseaux de transport optique. Ceux-ci formeront la base de la nouvelle génération des réseaux optiques de demain et permettront le déploiement efficace des services tel que le Cloud Computing. Cette évolution est destinée à apporter flexibilité et automatisation à la couche optique, mais s'accompagne d'une complexité supplémentaire, notamment au niveau de la gestion et de la commande de cette toute nouvelle génération de réseau. Jusqu'à récemment, les protocoles de routage et de signalisation normalisés ont pris en compte plusieurs paramètres physiques tels que l'information spectrale de la bande passante, le format de modulation, et la régénération optique. Cependant, d'autres paramètres sont encore nécessaires (par exemple, les puissances optiques des liens, le gain des amplificateurs) afin de faire fonctionner efficacement de grands réseaux. Dans ce contexte, il y a un besoin d'étudier les réseaux optiques existants ainsi que les différentes méthodes de prise en compte de la couche photonique dans le plan de contrôle. Le but est d'avoir un réseau optique automatique, flexible et programmable, mais surtout efficace de point de vue économique et opérationnel. L'utilisation de la technologie à grille flexible a un impact sur les réseaux optiques existants, où presque tous les équipements devront être remplacés, ce qui entraînera un coût additionnel pour les opérateurs. Dans ce travail, nous étudions les réseaux optiques actuels et évaluons l'impact de la flexibilité sur les infrastructures existantes. Ensuite, nous identifions plusieurs paramètres optiques à contrôler et proposons des extensions protocolaires afin d'intégrer ces paramètres dans un plan de contrôle GMPLS. De plus, nous développons les algorithmes de routage et de signalisation qui permettent la mise en œuvre d'un plan de contrôle efficace qui répond au besoin de la flexibilité. Enfin, l'ensemble de nos propositions et de nos solutions sont évaluées sur plusieurs topologies réseaux avec des modèles de trafic différents dans le but de valider leur pertinence
Dynamic and flexible optical networks are among the evolution scenarios of the optical transport networks. These form the basis of the new generation of optical networks of tomorrow and enable the effective deployment of services such as cloud computing. This evolution is intended to provide flexibility and automation to the optical layer. However, it results in additional complexity, particularly in terms of the management and control of this new network generation. Until recently, the standardized routing and signaling protocols have been taking into account several optical parameters like the spectral bandwidth information, modulation format, and optical regeneration. However, other parameters (e.g., link optical powers, gain of optical amplifiers) are still required in order to efficiently operate large optical networks. In this context, there is a need to study the existing optical networks and the different integration methods of the photonic layer in a control plane. The goal is to get an automatic optical network that is flexible, programmable, and at the same time efficient from an economical and operational perspective. The use of flexible grid technology has an impact on existing optical networks, where almost all the equipment must be replaced, resulting in an additional cost to network operators. In this work, we study the current optical networks and evaluate the impact of flexibility on the existing infrastructures. Then, we identify several physical parameters to be controlled and propose protocol extensions in order to integrate these parameters in the GMPLS control plane. In addition, we develop the routing and signaling algorithms that allow the implementation of an efficient control plane that addresses the need for flexibility. Finally, the set of our proposals and solutions are evaluated on multiple network topologies with different traffic patterns in order to validate their relevance

碩士
國立臺灣科技大學
電子工程系
87
Flow aggregation in ATM networks can basically be categorized into two branches. The first one is VC-merge which requires more latency time and up to 53% more additional buffer than non-VC-merge. Especially, VC-merge with service class requires up to 83% more additional buffer than non-VC-merge for RSVP data flows. The second branch is VP-merge which has scalability problem resulted from the size of VPI field and VCI collision problem resulted from the size of VCI field. This thesis studies issues of aggregating RSVP flows and aggregating RSVP signaling messages in MPLS networks. Two aggregation mechanisms are proposed. The first mechanism is the VC-merge with QoS level which aggregates data flows with QoS request by combining the advantage of VC-merge and VP-merge. This mechanism requires 23% more additional buffer than non-VC-merge for RSVP data flows. The second one is RSVP signaling message aggregation which aggregates several RSVP control messages to a new one so as to reduce the number of RSVP control messages to be processed in label switching routers (LSRs) and to conserve the bandwidth in transferring these messages. The results indicate that VC-merge with QoS level mechanism reduces the label consumption from O(M’N2) to O(K’N), requires less buffer than the VC-merge does, provides reasonable QoS for each flow in the same merged link, and solves the VCI collision problem, where M is the number of RSVP flows in each ingress LSR, N is the number of ingress LSRs and K is the QoS levels. The RSVP signaling message aggregation mechanism reduces the number of RSVP signaling messages from O(M’N) to O(N) while most flows are RSVP flows. 1.1 RSVP 1 1.2 IP over ATM 4 1.3 Multi-Protocol Label Switching 5 1.4 RSVP over MPLS 6 1.5 Stream Aggregation 9 1.6 Others issues 13 1.7 Plans of This Thesis 15 Chapter 2 Stream Aggregation Problem 17 2.1 VC-Merge Mechanisms 18 2.2 VP Merging Mechanisms 22 Chapter 3 VC Merging with QoS Level Mechanism 25 3.1 Format of Cell Header 25 3.2 VCI Assignment Mechanism 26 3.3 Architecture of LSR 28 3.4 Extending RSVP protocol 30 Chapter 4 Simulation Results and Comparison 38 4.1 Simulation Model 38 4.2 Simulation Results 40 4.3 Numerical Analysis 45 Chapter 5 RSVP Signaling Message 47 5.1 Related Works 47 5.2 RSVP Signaling Message Aggregation Mechanism 53 5.3 Simulation Results 55 Chapter 6 Conclusion 58 References 61

As Multi-Protocol Label Switched (MPLS) networks increase in usage and size, the number of traffic engineered tunnels or Label Switched Paths (LSPs) which must be established has an impact on network state maintenance, administration and scalability. The ability to signal and meet Quality-of-Service (QoS) requirements in such networks has been addressed through the addition of Differentiated Services (Diff-Serv) mappings and other traffic engineering mechanisms. However, for the purpose of path computation, route advertisements, signaling and admission control, multiple traffic classes carried together are still treated as a single class. This work explores extensions to MPLS which allow for the accommodation of up to eight distinct traffic classes per label switched path. Through an examination of simulation results. a comparison between existing methods and the proposed additions is made that shows scenarios in which such traffic class aggregation or "bundling" provides a significant reduction in the number of paths which must be maintained in the network.

博士
國立成功大學
電腦與通信工程研究所
105
Internet protocol (IP) is the most widely used protocol for high-bandwidth data transmission and it has been thought as a solution to provide different high-quality services in the future. As the internet traffic increases rapidly, the network size is extended. Multi-protocol label switching (MPLS) is proposed to reduce the IP processing time because only label is processed during the packet transmission between nodes. Although MPLS partially releases the burden of IP network, packet routing still faces a bottleneck when the number of users is large. Optical packet switching (OPS) overcomes this difficulty by simplifying several layers into IP over optical network. To implement MPLS over optical work, optical codes (OC) are used as labels for packet switching in Generalized MPLS (GMPLS) network. Among several label approaches, spectral amplitude coding (SAC) lowers system complexity and is compatible with label stacking. The label of an optical pocket is composed by different wavelength components, which are encoded according to a signature code pattern. However, due to the incoherent property of light source, the phase intensity induced noise (PIIN) appears at the forwarding node when the optical code label is de-coded. PIIN cannot simply removed by increasing the signal power because its value is proportional to the detected optical current. Therefore, we design three optical code labelling (OCL) scenarios, to increase the probability of correctly decoding the label in core nodes (CNs). Since the packet is sent to the appropriate path, the label error rate (LER) at edge node (EN) is decreased. In the first approach, stuffed quadratic congruence code (SQC code) is proposed for optical label implementing. Because of its low cross-correlation value, the effect of PIIN can be decreased significantly. If the label can be decoded correctly, the forward node would generate proper control signal to direct the packet to a suitable path. This reduces the probability of packet missing and lowers the value of LER when optical packet is de-modulated at the end node. For the case of label stacking, labels with SQC codes can provide greater system improvements. To meet practical applications, the relation between SAC-labels and optical MPLS network performance is also analyzed in this dissertation by numerical simulation. In the second approach, a hybrid label for optical packet switching in GMPLS network is proposed by combining SAC optical code-division multiple access (OCDMA) with wavelength division multiplexing (WDM). The author considers two label assignment scenarios. Hybrid labels are sequentially assigned to path segments in a label switching path (LSP) based on code index or wavelength index. LER performance of these two label assignment scenarios are also analyzed. Better LER results is achieved by sequential wavelength assignment, due to the similar label numbers among wavelengths. Furthermore, the optimal channel number is derived to minimize the LER under a specific number of stacked labels. In the final approach, bipolar OCL is employed in GMPLS network to improve the efficiency of label-recognition and network throughput. Label switching capabilities in LER is greatly reduced since the proposed bipolar OCL enlarges the Hamming distance of the star diagram of the decoded label signals. The proposed label mapping mechanism is also achieved through SAC in physical layer. In performance analysis, a numerical simulation of LER is presented to quantify the switching efficiency. Results show the proposed bipolar coding technique reduces LER in switching process, resulting in an extension of LSP in GMPLS core network.

碩士
國立臺灣科技大學
電子工程系
87
Multi-Protocol Label Switching (MPLS) is a new technique which is expected to provide a higher bandwidth capacity with QoS-guaranteed services and a faster packet forwarding mechanism than the traditional store-and-forward routing mechanism that is still being used currently over data networks. Mobility is becoming an attractive feature in modern communication network design. It is promising to use the MPLS framework, the span or partiality of the routing path, to support mobile services in the future. Mobile IP is operated in connectionless mode and is currently used in the Internet to support mobility. On the other hand, MPLS is expected to work with Internet in connection-oriented mode. To support mobility, an MPLS based Internet has to deal with the handoff rerouting problem. In this thesis, we study MPLS as well as the mobility in order to provide efficient host mobility for the wired backbone network with MPLS capability. The main focus of this thesis is the design and comparison of the three handoff rerouting schemes, the all rebuilt rerouting scheme, the extended rerouting scheme, and the LSP rerouting scheme for the support of host mobility over MPLS networks. Special functions such as LSP reservation and loop removal are also considered to further improve the three rerouting schemes. Simulations were performed to compare the rerouting latency and end-to-end delay among these rerouting schemes. We can observe the characteristics of these rerouting schemes implemented in the MPLS network from simulation results. The results show that the performance of the LSP rerouting scheme outperforms among the proposed schemes.

碩士
國立成功大學
電腦與通信工程研究所
102
Nowadays, internet has become an indispensable part of our life. Internet protocol (IP) is the general protocol in the network. In classical IP network, the data packet is routed to the destination according to its IP address at each router. With the development of technique, the processing load of router becomes huge since the rapid increasing of information and multimedia data. To provide large number of clients searching for high-quality applications, evolvement of internet with faster information transportation is needed. Recent years, multi-protocol label switching (MPLS) presents an answer. It simplifies the forwarding function of routers. Since the label de-composition in network layer is averted, great processing delay is shortened at each node. In this thesis, we propose a structure for achieving optical MPLS. This structure uses spectral-amplitude coding optical code-division multiple-access (SAC-OCDMA) and label stacking techniques to generate the optical labels and be added to data packet. Each router implements fast label switching by recognizing the stacking labels only. In analyzing the system performance, we emphasize the part of label recognition. We have considered the effects of thermal noise and phase-induced intensity noise (PIIN) which causing the bit error rate of label recognition. The results show that when the number of stacking labels increase, the BER will become large. If we want to achieve better BER, the bigger code length for generating optical labels is need.

Wen Yonggang.
Thesis (M.Phil.)--Chinese University of Hong Kong, 2001.
Includes bibliographical references.
Abstracts in English and Chinese.
Chapter 1 --- Introduction
Chapter 1.1 --- Multi-Protocol Label Switching (MPLS) Technology --- p.1
Chapter 1.2 --- Objective of this Thesis --- p.4
Chapter 1.3 --- Reference --- p.5
Chapter 2 --- Optical MPLS Network and Optical Label Schemes
Chapter 2.1 --- Optical MPLS Network --- p.7
Chapter 2.2 --- Optical Label Schemes --- p.10
Chapter 2.2.1 --- Time-division OMPLS scheme --- p.12
Chapter 2.2.2 --- Wavelength-division OMPLS scheme --- p.16
Chapter 2.2.3 --- Frequency-division OMPLS scheme --- p.22
Chapter 2.2.3.1 --- UCSB Testbed --- p.23
Chapter 2.2.3.2 --- UC-Davis Testbed --- p.26
Chapter 2.2.3.3 --- NCTU-Telecordia Testbed --- p.28
Chapter 2.2.4 --- Code-division OMPLS scheme --- p.30
Chapter 2.2.4.1 --- Coherent Code-Division Label Scheme --- p.30
Chapter 2.2.4.2 --- Noncoherent Code-Division Label Scheme --- p.32
Chapter 2.3 --- Reference --- p.35
Chapter 3 --- Architecture of OOC-based OMPLS network
Chapter 3.1 --- Infrastructure of OOC-label switch router (code converter) --- p.37
Chapter 3.1.1 --- Architecture of the Proposed Code Converter --- p.38
Chapter 3.1.2 --- Enhancement of the Code Converter --- p.41
Chapter 3.2 --- Implementation of the OOC code converter --- p.43
Chapter 3.2.1 --- Encoders/Decoders --- p.43
Chapter 3.2.1.1 --- All-parallel encoders/decoders --- p.43
Chapter 3.2.1.2 --- All-serial encoders/decoders --- p.45
Chapter 3.2.1.3 --- Serial-to-parallel encoder/decoders --- p.47
Chapter 3.2.1.4 --- Comparison of the three kinds of encoders/decoders --- p.49
Chapter 3.2.2 --- Time-Gate-Intensity-Threshold (TGIT) Device --- p.50
Chapter 3.2.3 --- Optical Space Switch Array --- p.54
Chapter 3.2.3.1 --- All-optical Space Switch --- p.54
Chapter 3.2.3.2 --- Optical switching technologies --- p.56
Chapter 3.2.3.2.1 --- Scalability --- p.56
Chapter 3.2.3.2.2 --- Switching Speed --- p.57
Chapter 3.2.3.2.3 --- Reliability --- p.57
Chapter 3.2.3.2.4 --- Losses --- p.58
Chapter 3.2.3.2.5 --- Port-to-Port repeatability --- p.58
Chapter 3.2.3.2.6 --- Cost --- p.59
Chapter 3.2.3.2.7 --- Power Consumption --- p.60
Chapter 3.3 --- Reference --- p.61
Chapter 4 --- Scalability of OOC-based MPLS network
Chapter 4.1 --- Limitation on Label Switching Capacity --- p.63
Chapter 4.1.1 --- Upper Bound --- p.65
Chapter 4.1.2 --- Lower Bound --- p.66
Chapter 4.2 --- Limitation on Switching Cascadability --- p.70
Chapter 4.2.1. --- Limit Induced by the Inter-channel Crosstalk --- p.70
Chapter 4.2.2 --- Limits Induced by the Residue Intensity of Sidelobes --- p.74
Chapter 4.3 --- Appendix --- p.78
Chapter 4.3.1 --- Derivation of Chip Intensity --- p.78
Chapter 4.3.2 --- The 5% residue power criterion --- p.81
Chapter 4.4 --- Reference --- p.83
Chapter 5 --- Conclusion
Chapter 5.1 --- Summary of the Thesis --- p.85
Chapter 5.2 --- Future work --- p.86

博士
元智大學
電機工程學系
95
As a cutting-edge high-speed network communication technique, GMPLS (Generalized Multi-Protocol Label Switching) plays a role of conversion and interface in various network communication hardware and optical communications, allowing different network hardware systems to be connected with one another and co-exist in a single network system. The progress in optical techniques facilitates the skyrocketing demands for optical networks in urban network. At present, the most significant challenge in digital services is the integration of Internet protocol (IP) and optical layers, which will be the core for the next expansion of Internet. GMPLS has greatly improved the difficulties of IP-based networks used currently. The traffic engineering improvement in it automatically creates IP tunnels, as well as crosses the transmission platform of the 2nd layer transmission of ATM and that of the 3rd layer transmission of IP, simplifying the management of networks and reducing system complexity. However, the Open Shortest Path First (OSPF) technique used in GMPLS adopts the Dijkstra''s Algorithm to obtain the Shortest Path Tree needed for network communications and to transmit packets. Yet, this way is unable to handle the actual dynamic conditions and situations in network, which does not place the path at the optimal status, as well as results in partial network congestion. This dissertation investigates the algorithms for GMPLS routing and proposes Genetic Algorithms (GAs) architecture to replace to current OSPF algorithm. The application of Genetic Algorithms, with their genetic characteristics and the ability of self-evolution, is not only applied to GMPLS routing, traffic management and routing algorithm, but also provides better QoS (Quality of Service), allowing improvement of aggressiveness and progressiveness in the ability of GMPLS transmission in path selection, while enabling high-speed optical networks to provide the optimized performance。

Die schichtenübergreifende Steuerung von Multi-Layer Netzen ermöglicht die Realisierung fortgeschrittener Netzarchitekturen sowie neuartiger Konzepte zur Steigerung der Ausfallsicherheit. Gegenstand dieser Arbeit ist ein neues ressourcensparendes Konzept zur Kompensation von Core-Router-Ausfallen in IP-Netzen. Core-Router-Ausfälle führen zur Abkopplung der an Ihnen angeschlossenen Zugangsrouter vom Netz. Daher werden die Zugangsrouter üblicherweise mit jeweils zwei oder mehreren verschiedenen Core-Routern verbunden (engl.: dual homing) was jedoch eine Verdoppelung der Anschlusskapazität im IP Netz bedingt. Bei dem neuen Verfahren - Dual Homing mit gemeinsam genutzten Router-Ersatzressourcen (engl.: dual homing with shared backup router resources, DH-SBRR) - erfolgt die Zugangsrouter-Anbindung zum einen zu einem Core-Router des IP-Netzes und zum anderen zu einem Netzelement der darunterliegenden Transportschicht. Damit lassen sich Router-Ersatzressourcen, die im IP-Netz an beliebigen Stellen vorgehalten werden können, uber das Transportnetz an die Stelle eines ausgefallenen Core-Routers schalten. Die Steuerung dieser Ersatzschaltung geschieht über eine schichten übergreifende, d.h. das Transportnetz- und IP-Netz umfassende Control-Plane - beispielsweise auf Basis von GMPLS. Da beim Umschalten der Routerressourcen auch aktuelle Zustände (bspw. Routing-Tabellen) auf die Router-Ersatzressourcen mit übertragen werden müssen, beinhaltet das neue Verfahren auch Konzepte zur Router-Virtualisierung. Zum Vergleich und zur Bewertung der Leistungsfähigkeit des neuen DH-SBRR Verfahrens werden in der Arbeit verschiedene Zugangsrouter-Homing-Varianten hinsichtlich Netz-Kosten, Netz-Verfügbarkeit, Recovery-Zeit und Netz-Energieverbrauch gegenübergestellt. Als Multi-Layer Netzszenarien werden zum einen IP über WDM und zum anderen IP über OTN (ODU) betrachtet. Zur Bestimmung der minimalen Netz-Kosten ist ein generisches Multi-Layer Netzoptimierungsmodell entwickelt worden, welches bei unterschiedlichen Homing-Architekturen angewendet werden kann. Neben dem Optimierungsmodell zur Netzkostenminimierung wird auch eine Modellvariante zur Minimierung des Energieverbrauchs vorgestellt. Um die Rechenzeit für die Lösung der Optimierungsprobleme zu verringern und damit auch größere Netzszenarien untersuchen zu können bedarf es heuristischer Lösungsverfahren. Im Rahmen der Arbeit ist daher eine neue speziell auf die Multilayer-Optimierungsprobleme zugeschnittene Lösungsheuristik entwickelt worden. Aus der Netzkosten-Optimierung ergibt sich, dass durch den Einsatz von DH-SBBR signifikante Kosteneinsparungen im Vergleich zu herkömmlichen Homing-Architekturen realisiert werden können. Änderungen der Verkehrslast, der Kosten der IP-Netzelemente oder der Netztopologie haben keinen signifikanten Einfluss auf dieses Ergebnis. Neben dem Kosten- und Energieeinsparungspotential sind auch die Auswirkungen auf die Netz-Verfügbarkeit und die Recovery-Zeit untersucht worden. Für die Ende-zu-Ende Verfügbarkeit bei Anwendung der verschiedenen Homing-Architekturen Können untere Grenzwerte angegeben werden. Zur Bestimmung der Recovery-Zeit bei Einsatz von DH-SBRR ist ein eigenes analytisches Berechnungsmodell entwickelt und evaluiert worden. Damit kann das DH-SBRR Verfahren zur Einhaltung vorgegebener Recovery-Zeiten (wie sie für bspw. Für bestimmte Dienste gefordert werden) entsprechend parametriert werden.
The emergence of multi-layer networking capabilities opens the path for the development of advanced network architectures and resilience concepts. In this dissertation we propose a novel resource-efficient homing scheme: dual homing with shared backup router resources. The proposed scheme realizes shared router-level redundancy, enabled by the emergence of control plane architectures such as generalized multi-protocol label switching. Additionally, virtualization schemes complement the proposed architecture. Different homing architectures are examined and compared under the prism of cost, availability, recovery time and energy efficiency. Multiple network layers are considered in Internet protocol over wavelength division multiplexing as well as Internet protocol over optical data unit settings - leading to the development of multi-layer optimization techniques. A generic multi-layer network design mathematical model, which can be applied to different homing architecture considerations, is developed. The optimization objective can be adapted to either minimizing the cost for network equipment or the power consumption of the network. In order to address potential issues with regard to computational complexity, we develop a novel heuristic approach specifically targeting the proposed architecture. It is shown that significant cost savings can be achieved - even under extreme changes in the traffic demand volume, in the cost for different types of network equipment, as well as in the network topology characteristics. In order to evaluate occurring tradeoffs in terms of performance, we study the effects on availability and recovery time. We proceed to derive lower bounds on end-to-end availability for the different homing architectures. Additionally, an analytical recovery time model is developed and evaluated. We investigate how service-imposed maximum outage requirements have a direct effect on the setting of the proposed architecture.