Les réseaux Telecom sont désormais en charge du transport d’une large variété de trafic de types donnés, voix, vidéo et autres protocoles industriels réclamant des garantie de qualité de service strictes. L’ingénierie de trafic permet non seulement d’optimiser les ressources réseaux mais aussi de parvenir à garantir ces qualités de service exprimées en termes de délais dans le réseau, de gigue mais aussi de taux de disponibilité en présence de pannes de liens ou de nœuds. La technologie MPLS TE, basée sur la commutation de labels le long de chemins contraints a permis d’atteindre ces objectifs et fut déployée dans de nombreux réseaux. L’objectif de cette thèse est de proposer un nouveau modèle architectural nommé PCE, ainsi que des protocoles et algorithmes novateurs afin de résoudre plusieurs problèmes d’envergure liés à l’ingénierie de trafic et disponibilité du réseau. L’architecture PCE est tout d’abord décrite ainsi que le protocole de signalisation PCEP utilisé entre clients et serveurs, puis les protocoles de découvertes de PCE et algorithmes de partage de charge. Ensuite un nouvel algorithme récursif est spécifié permettant grâce à un calcul collaboratif et récursif distribué impliquant une suite de PCEs de calculer le chemin optimal pour des tunnels inter-domaines. Un nouveau paradigme pour le calcul des chemin de secours est spécifié qui permet à chaque nœud d’agir en tant que PCE pour le calcul des tunnels de secours de chacun de ses voisins dans l’hypothèse que sa propre panne, permettant une utilisation partagée des ressources réseau dédiées au secours pour des tunnels protégeant des ressources indépendantes... / Modern data networks carry a wide variety of traffic such as voice, video, data and other industrial protocols that require guaranteed quality of service. Traffic Engineering (TE) allows for network resource optimization while meeting service level agreement for these sensitive traffics in terms of delays, jitter but also network reliability in case of network element failure. To that end a technology making use of constrained paths using label switching (called MPLS TE) has been developed and widely used in a number of networks. The objective of this thesis is to propose a new architecture model referred to as the Path Computation Element (PCE) along with a number of protocols and algorithms in order to tackle a number of technical challenges. First the PCE architecture is described in terms of functional blocks with its protocols: the signalization protocol called PCEP used between client and servers in charge of computing label switched path in the network, the process of PCE discovery and load balancing. Then a new backward recursive algorithm is specified allowing for the computation of optimal inter-domain tunnels, which involves a series of stateless PCEs. We then introduce a paradigm shift consisting distributing the computation of backup tunnels in the network used by the well-known technology called Fast Reroute. Thanks to this new paradigm, each node independently acts as a PCE computing the back tunnels of all of its neighbors, thus maximizing the degree of sharing of the backup capacity among tunnels that protect independent resources. We conclude this thesis by showing how the PCE architecture can be applied (with adaptations specified in the last two chapt...

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During the last years, MultiProtocol Label Switching (MPLS) has been deployed by most large Service Providers (SP). The main driver for MPLS deployment is the ability to provide new services with stringent Service Level Agreements (SLAs) such as layer-2 and layer-3 Virtual Private Networks (VPNs) as well as Voice and Video over IP. Most of these services are already deployed inside single SP networks. However, customers now require world-wide VPN and VoIP services. Therefore, SPs need to collaborate to offer these services across multiple SP networks. Inside a single SP network, each node usually knows the complete topology of the network with the load and delay of all the links. Based on this information, each router is able to compute constrained paths toward any other router inside the SP network. Then, it can establish a connection and reserve resources along the computed path with the Resource reSerVation Protocol (RSVP-TE). However, when services with stringent requirements must cross multiple SP networks the computation of the path becomes a problem. Routers in different SP networks exchange routing information by using the Border Gateway Protocol (BGP). BGP provides reachability information. It does not distribute complete topology, delay and bandwidth information. One way to provide guaranteed services crossing different SPs is to delegate the computation of the paths to a Path Computation Element (PCE) that learns the topology of the different SPs. However, this requires that SPs reveal information that they usually consider confidential, their topology. In this thesis, we perform active measurements to show the difficulty to engineer the interdomain traffic with BGP. MPLS together with RSVP-TE provide much more control on the traffic. We define extensions to RSVP-TE for the protection of inter-AS MPLS paths. The aim is to be able to provide the same service guarantees as inside a domain while keeping the internal topology of SPs confidential, as required by SPs. We propose and evaluate distributed techniques relying on PCEs for the computation of interdomain constrained paths respecting the latter confidentiality requirement.

In recent years, IP based end-to-end services have grown in popularity. Efficiently meeting the user demand for such services, different techniques for traffic engineering transport networks have been developed. One such technique, currently being developed for multilayered networks, is Generalized Multi-Protocol Label Switching (GMPLS). GMPLS is a necessary networking technique because provisioning end-to-end services will today, and in the foreseeable future, very likely require the co-operation of multiple network layers. Here, the readiness of GMPLS for optical networks is investigated by reviewing the current support for optical networking components in the GMPLS standard documents. Based on this investigation, a candidate solution for routing and constraint-based path computation in optical network segments has been derived. This candidate solution is shown to efficiently handle the additional attributes and constraints inherent in optical networking components. / De senaste åren har IP-baserade tjänster ökat i popularitet. För att effektivt möta de användarkrav som ställs på sådana tjänster har olika tekniker för att styra transportnätverk utvecklats. En sådan teknik, nu under utveckling för multi-lagrade nätverk, är GMPLS. GMPLS är en nödvändig nätverksteknik eftersom tillhandahållandet av sluttjänster mellan olika användare idag, och inom en överskådlig framtid, mycket sannolikt kommer att kräva samarbete mellan flera nätverkslager. Här undersöks GMPLS färdighet i optiska nätverk genom att se över det nuvarande stödet för optiska nätverkskomponenter i GMPLS standarddokument. Baserat på denna undersökning har en kandidatlösning för routing och begränsad vägberäkning i optiska nätverkssegment tagits fram. Denna kandidatlösning visas effektivt hantera de ytterligare attribut och restriktioner som existerar i optiska nätverkskomponenter.