The thesis report provides broader information about IP and MPLS technologies and routing protocols. Internet architecture and problems in an IP networks are illustrated when different internet protocols are used. Small focus is provides on the demand oriented real time applications and data traffic for QoS parameters in IP and MPLS networks. Evaluation of QoS guarantee parameters such as delay, jitter and throughput are described with state of art study results mainly for real time applications in IP and MPLS networks. Finally MPLS TE implementation and working is described and proposed to achieve better network performance.

Acredita-se que no futuro as redes de telecomunicação e dados serão integradas em uma só rede, baseada na comutação de pacotes IP. Esta rede deverá oferecer serviços com qualidade (QoS) para as aplicações atuais e futuras. Uma das tecnologias que deverá ser adotada no núcleo desta nova rede é MPLS. MPLS introduz o conceito de switching (comutação) no ambiente IP e também permite que seja implementada a Engenharia de Tráfego, otimizando sua utilização através do roteamento baseado em restrições. Junto com MPLS outras arquiteturas para fornecimento de QoS, como Serviços Integrados e Serviços Diferenciados, serão utilizadas. Entretanto, como nenhuma delas atende a todos os requisitos para garantia de QoS fim a fim e levando-se em consideração o fato de a Internet ser uma rede heterogênea, surge a necessidade de um framework que permita a interoperabilidade das diferentes arquiteturas existentes. Neste trabalho é proposto um modelo de integração que fornece garantias de QoS fim a fim para redes que utilizam tanto Serviços Integrados como Serviços Diferenciados através do emprego de uma infra-estrutura baseada em MPLS e Serviços Diferenciados. A aplicabilidade do modelo foi testada no simulador ns2 e os resultados são apresentados neste trabalho.

La majorité des grands opérateurs utilise la technologie MPLS pour gérer leur réseau via des protocoles de signalisation et de distributions de labels. Or, ces protocoles sont complexes à déployer, à maintenir et la résolution des pannes est souvent très difficile. L'IETF a initié la standardisation d'une architecture de routage par segments (Segment Routing) s'appuyant sur un plan de contrôle simple, léger, facile à gérer et instanciée sur MPLS ou IPv6. Cette architecture repose sur le concept de routage à la source, dans lequel l'en-tête des paquets transporte les indications du chemin à suivre pour atteindre sa destination. Adapté aux cas d'usages simples et offrant nativement une résistance aux pannes, les cas d'usages plus complexes exigent de résoudre des verrous technologiques pour lesquels nous proposons plusieurs solutions. Dans cette thèse effectuée au sein d'Orange Labs, nous nous sommes intéressés à l'instanciation de l'architecture Segment Routing sur le plan de transfert MPLS et plus particulièrement à l'ingénierie de trafic, notamment avec réservation de ressources. Nous avons proposé des solutions aux problèmes liés à la limitation matérielle des routeurs actuels ne permettant pas l'expression de tous les chemins contraints. Ce travail est divisé en deux parties : (i) la proposition d'algorithmes de calcul et d'encodage de chemins de routage par segment afin de contourner les limitations matérielles. (ii) la définition des exigences architecturales et la construction d'une preuve de concept fonctionnelle. Enfin, cette thèse propose de nouvelles pistes d'études afin de consolider les outils d'ingénierie de trafic pour le routage par segment. / Most major operators use MPLS technology to manage their network via signalling and label distribution protocols. However, these protocols are complex to deploy, maintain and troubleshooting is often very difficult. The IETF has initiated the standardization of a segment routing architecture based on a simple control plane, lightweight, easyto-manage and instantiated on MPLS or IPv6. This architecture is based on the concept of source routing, in which the packet header carries the indications of the path to follow to reach its destination. Suitable for simple use cases and natively resistant to failure, more complex use cases require the resolution of technological issues for which we offer several solutions.In this thesis carried out within Orange Labs, we were interested in the instantiation of the Segment Routing architecture on the MPLS transfer plan and more particularly in traffic engineering, particularly with resource reservation. We have proposed solutions to the problems related to the hardware limitation of current routers that do not allow the expression of all constrained paths. This work is divided into two parts : (i) the proposal of algorithms for computing and encoding segment routing paths in order to bypass hardware limitations. (ii) the definition of architectural requirements and the construction of a functional proof of concept. Finally, this thesis proposes new research issues to consolidate traffic engineering tools for segment routing.

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

MPLS is a widely used technology in the service providers and enterprise networks across the globe. MPLS-enabled infrastructure has the ability to transport any type of payload (ATM, Frame Relay and Ethernet) over it, subsequently providing a multipurpose architecture. An incoming packet is classified only once as it enters into the MPLS domain and gets assigned label information; thereafter all decision processes along a specified path is based upon the attached label rather than destination IP addresses. As network applications are becoming mission critical, the requirements for fault tolerant networks are increasing, as a basic requirement for carrying sensitive traffic. Fault tolerance mechanisms as provided by an IP/MPLS network helps in providing end to end “Quality of Service” within a domain, by better handling blackouts and brownouts. This thesis work reflects how MPLS increases the capability of deployed IP infrastructure to transport traffic in-between end devices with unexpected failures in place. It also focuses on how MPLS converts a packet switched network into a circuit switched network, while retaining the characteristics of packet switched technology. A new mechanism for MPLS fault tolerance is proposed.

This paper proposes a new approach to support restoration of Label Switched Paths (LSP) set up in the MPLS network. The proposed scheme tries to establish all possible bypass tunnels according to the maximum bandwidth between two LSR around the protected Label Switched Router (LSR). The proposed scheme uses the idea of the maximum bandwidth between two LSRs and establishes the bypass tunnels passing through the critical links which will affect the maximum bandwidth between two LSRs. All of LSPs affected by a LSR failure or a link failure can choice a bypass tunnel fit its QoS constraints to reroute. This paper also compares the different between the proposed bypass tunnel and link disjoint bypass tunnel. The simulation result show that the proposed approach has better packet loss in rerouting and can allow more affected LSP to reroute compare to RSVP and efficient Pre-Qualify. The proposed bypass tunnels have better performance than link disjoint bypass tunnels.

Nowadays, MPLS VPN has become a widely used solution on the issue of QoS guarantees against unexpected changes of network environments. This thesis investigates the system performance of the BGP-based MPLS VPN, which supports per class differentiated services. The results are compared with those without VPN. In this study, the target network is simulated through the OPNET simulator. Through adjusting the network parameters and creating different scenarios, such as network congestion and disconnection, we make statistical analyses based on the simulation results. It is observed that in addition to increasing the labels contained in each packet, MPLS VPN require PE routers be capable of supporting more protocols, such as searching for IP tables, and transferring various tables for the use of routing. Therefore, introducing VPN may increase processing load and overhead for data transmission. On the other hand, MPLS VPN may take longer convergence time in establishing entire routing messages than Non-VPN. However, when network disconnection occurs, the former has better throughput than the latter due to the shorter convergence time in the search of new routes. Also, if the networks become congested, the transmission delay of EF traffic in MPLS VPN is smaller since the alternative LSP for it is pre-established. For the same disconnected LSP route, MPLS VPN network also achieves better throughput, because the guaranteed EF traffic can be rerouted via different LSP routes. According to our simulation results, the background traffic has the largest throughput decrease, while the EF Traffic has the least.

In MPLS networks, CR-LDP (Constraint-Based Routed Label Distribution Protocol) provides traffic engineering and QoS (Quality of Service) by distributing labels along the path. One of the innovative ideas in CR-LDP is right in the capability of bandwidth preemption. Bandwidth preemption allows a high-priority traffic flow to pre-empt the low-priority traffic flow when there is not enough bandwidth for conveying the high-priority flow. However, it is not effective in assuring QoS by simply pre-empting the low-priority flow. Therefore, in the thesis, we present a bandwidth preemption with negotiation (BPN) architecture for MPLS networks. In BPN, a high-priority flow will have to negotiate the bandwidth with Ingress Switch Router (ISR) before it can actually pre-empt the bandwidth being used by the low-priority flow. A network link-state database in ISR is designed to record the remaining bandwidth for each priority class. ISR determines whether a high-priority flow can pre-empt a low-priority flow based on the condition that the low-priority flow is possible to switch to other paths with an equal bandwidth along the path. In order to evaluate the performance of our proposed BPN mechanisms, we modify the MNS (MPLS Network Simulator) by adding a bandwidth negotiation module. For the comparisons, we design two topologies for simulating the proposed BPN and the traditional bandwidth preemption with force mode. It is observed that the BPN have exhibited better performance in average throughput and packet loss rate than the traditional bandwidth preemption, not matter either a complex or a regular topology is used. Finally, we analyze the BPN algorithm complexity by some network parameters, and compare the complexity with that of traditional bandwidth preemption

Thèse de doctorat : Automatique : Nancy 1 : 2009. / Titre provenant de l'écran-titre.

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