This research focuses on developing a set of secure communication network testbeds and using them to measure the overhead of IP Security (IPSec) for email and web applications. The network testbeds are implemented using both wireline and wireless technologies. The testing involves a combination of authentication algorithms such as Hashed Message Authentication Code-Message Digest 5 (HMAC-MD5) and Hashed Message Authentication Code-Secure Hash Algorithm 1 (HMAC-SHA1), implemented through different authentication protocols such as ESP and AH, and used in conjunction with the Triple Digital Encryption Standard (3DES). The research examines the overhead using no encryption and no authentication, authentication and no encryption, and authentication and encryption. A variety of different sizes of compressed and uncompressed files, are considered when measuring the overhead. The testbed realizes security using IPSec to secure the connection between different nodes. The email protocol that is used is the Simple Mail Transfer Protocol (SMTP) and the web protocol considered is the Hyper Text Transfer Protocol (HTTP). The key metrics considered are the network load in bytes, the number of packets, and the transfer time. This research emphasizes the importance of using HTTP to access files than using SMTP. Use of HTTP requires fewer packets, lower network loads, and lower transfer times than SMTP. It is demonstrated that this difference, which occurs regardless of security, is magnified by the use of authentication and encryption. The results also indicate the value of using compressed files for file transfers. Compressed and uncompressed files require the same transfer time, network load and number of packets since FreeS/WAN IPSec does not carry any form of compression on the data before passing it to the data link layer. Both authentication algorithms, HMAC-MD5 and HMAC- SHA1, result in about the same network load and number of packets. However, HMAC-SHA1 results in a higher transfer time than HMAC-MD5 because of SHA1's higher computational requirements. ESP authentication and ESP encryption reduce the network load for small files only, compared to ESP encryption and AH authentication. ESP authentication could not be compared with AH authentication, since the FreeS/WAN IPSec implementation used in the study does not support ESP authentication without using encryption. In a wireless environment, using IPSec does not increase the network load and the number of transactions, when compared to a wireline environment. Also, the effect of security on transfer time is higher compared to a wireline environment, even though that increase is overshadowed by the high transfer time percentage increase due to the wireless medium. / Master of Science

This thesis addresses the paucity of research on network mobility with a taxonomy and a quantitative comparison on a real test bed of existing and forthcoming network mobility solutions. Broadly, network mobility solutions can be divided into two broad categories, intra-domain and inter-domain solutions. The two are distinct enough to warrant separate solutions. Network mobility solutions can also be divided into four catogories according to their implementation, (i) Mobile IP-based solutions, (ii) Mobile IP Mobile Routing, (iii) intra-domain routing protocols, and (iv) Mobile IP Foreign Agent-based solutions. This latter division by implementation serves as a useful starting point for a discussion and study of these protocols. The qualitative and quantitive comparisons presented here yield two "winning" solutions, Mobile IP with Network Address Translation (NAT) and Mobile IP Mobile Routing, both based on Mobile IP, the draft standard for Internet mobility. The two were chosen because they are the only solutions fit for production networks, not necessarily because they are the best performing solutions. Indeed, nearly all of the other solutions are promising alternatives and some, such as mobile ad hoc network (MANET) routing protocols and the solutions based on the next generation Internet (IPv6) version of Mobile IP, are particularly so. One of the solutions uses a novel extension for Mobile IP, the Multiple Home Address extension, developed and specified in this thesis, that turns a Mobile IP mobile node into a mobile router able to support dynamically sizing mobile networks while using the existing Mobile IP infrastructure. / Master of Science

Η εργασία που παρουσιάζεται αφορά την ανάπτυξη ενός ενσωματωμένου συστήματος σε πολλαπλές επαναπρογραμματιζόμενες συσκευές (FPGAs), η επικοινωνία των οποίων γίνεται με τη χρήση του πρωτόκολλου επικοινωνίας TCP/IP. Αρχικά ορίστηκε σε κάθε επαναπρογραμματιζόμενη συσκευή, ένας ενσωματωμένος επεξεργαστής ΜicroBlaze, που ακολουθεί αρχιτεκτονικά την τεχνολογία RISC. Για την κατασκευή της TCP/IP συνδεσιμότητας, αναπτύθηκε σε κάθε core το απαιτούμενο λογισμικό σε γλώσσα προγραμματισμού C, με τη χρήση του open source πρωτοκόλλου επικοινωνίας Light Weight IP. Το συγκεκριμένο πρωτόκολλο είναι ειδικά κατασκευασμένο για σχεδίαση ενσωματωμένων συστημάτων και οι δυνατότητες του οδήγησαν στην ανάπτυξη λογισμικού, προσαρμοσμένο στις απαιτήσεις της ΤCP επικονωνίας και των διαθέσιμων πόρων του επιλεγμένου ενσωματωμένου επεξεργαστή. Η μεταφορά δεδομένων μεταξύ των FPGAs, πραγματοποιήθηκε με την σύνδεση των boards σε έναν μεταγωγέα επιπέδου ζεύξης(Ethernet switch) και Ethernet καλωδίων επικοινωνίας. Ακολούθως, σε κάθε core υλοποίηθηκε σχεδίαση υλικού, η οποία ενσωματώθηκε στο υπόλοιπο υλικό μέσω του διαύλου επικοινωνίας του MicroBlaze επεξεργαστή, με τη μορφή ενός περιφεριακού IP core. Για την επικοινωνία του επιπρόσθετου υλικού με το ενσωματωμένο λογισμικό, χρησιμοποιήθηκαν μηχανισμοί υλικού όπως ουρές δεδομένων εισόδου και εξόδου. Mε αυτόν τον τρόπο, κατέστη δυνατή η ανάπτυξη ενός μηχανισμού που περιλαμβάνει την αποστολή δεδομένων από το κομμάτι του λογισμικού στο υλικό, τη λήψη των δεδομένων από την custom περιφερειακή λογική, την επεξεργασία τους στο κομμάτι του υλικού, την ανάγνωση τους από το λογισμικό και την μετάδοση τους μέσω TCP/IP σύνδεσης σε ένα άλλο αναπτυξιακό, το οποίο μπορεί με τον ίδιο μηχανισμό να επεξεργαστεί τα ληφθέντα δεδομένα. Συμπερασματικά , με έναν αρκετά συμβατό τρόπο , γίνεται εφικτή η κατανομή οποιασδήποτε λογικής σχεδίασης, σε κομμάτια υλικού, τα οποία έχοντας ενσωματωθεί σε ξεχωριστά αναπτυξιακά boards, έχουν τη δυνατότητα να μεταφέρουν και να επεξεργάζονται δεδομένα μεταξύ τους, με χρήση ενός μηχανισμού λογισμικού, υπεύθυνο για τη διαμόρφωση της TCP επικοινωνίας. / This paper presents the development of an embedded system in multiple fpgas, which communicate with each other using ΤCP/IP communication protocol. Initially, a RISC-based embedded MicroBlaze Processor was set, at each device. In order to construct the TCP/IP connectivity, the required software part was developed at each core in programming language C, using the open source communication protocol Light Weight IP. This specific protocol is developed especially for embedded system design and its capabilities allow the construction of a software application, tailored to the requirements of a ΤCP communication and the available resources of the chosen embedded core. The data transfer between the FPGAs, was made with the use of an Ethernet Switch. Each FPGA was connected to an Ethernet switch port via a two directional Ethernet cable. Subsequently, a hardware design was developed at each core, and the custom logic was connected to the MicroBlaze processor local bus as a custom ΙP core peripheral. The communication between the additional hardware part and the embedded software was established with the use of first-in-first-out hardware components for the inputs and outpus of the ΙP core. This led to a successful developed mechanism which includes the transfer of data from software to hardware, the data processing in hardware design, the software reading of the processed data, and finally the data transmission to another FPGA Βoard via TCP/IP communication. In conclusion, a hardware design distribution in multiple FPGAs can be made in a convetional way. The hardware parts, which are embedded in different boards, are able to process, send and receive data across the network, using the appropriate software which is responsible for the configuration of the TCP/IP communication.

Cette thèse s'inscrit dans une démarche Européenne de recherche sous l'égide du projet European Bus System of the Futur (EBSF). Ce projet vise à définir le bus de demain et de préparer son architecture embarquée, aux systèmes de transport intelligents (STI) critiques ou de divertissement, de plus en plus présents dans les véhicules. Les systèmes autrefois hétérogènes et autonomes, devrons à l'avenir communiquer sur une architecture orientée service (SOA) unique. L'objectif est d'optimiser le fonctionnement de l'architecture dans son ensemble grâce à des protocoles de communication ouverts et standards. C'est à partir de cette base, à laquelle nous avons activement apportée notre contribution, que notre thèse s'appuie. Le dimensionnement et la validation de ces architectures sont restés des éléments sans réponse à la suite du projet EBSF. Cette thèse présente premièrement une méthode dimensionnement des architectures STI basée sur les méthodes de décision multi-critères. Nous nous basons sur une étude poussée des besoins opérationnels collectés tout au long de la thèse. Dans un deuxième temps, nous adaptons le modèle de Criticité Mixte, définit dans le domaine du temps réel, aux flux de communication entre le véhicule et l'infrastructure. Enfin nous présentons les travaux réalisés dans le cadre de la standardisation européenne afin de promouvoir ce type d'architecture et les travaux de cette thèse / Intelligent Transportation systems (ITS) are massively used in the Public Transport sector since the Two decades. This profusion of systems on-board and off-board vehicles generates inter-operability issues. The growth of urban zones and the increase of public transport attractiveness, brought multi-modal constraints that are today limited due to a lack of architecture vision embracing all ITS. This thesis proposes to unify the architecture vision of on-board ITS. We based our technical architecture on the Service Oriented Architecture (SOA) proposed in the European Bus System of the Future (EBSF) project, in which this thesis actively contributed. We study first the global requirements of different transportation modes operated in Europe. Those requirements are a basis to the definition of technical constraints of a global architecture. Those constraints are ranked in terms of importance using a proposed method based on Multi-Criteria Decision Making (MCDM) techniques. The method that we propose permits to size the technical architecture. We then study the flow management of data, considering the context of operation of vehicles and the criticality of ITS applications. We propose to adapt the Real-time Mixed-Criticality model to communication systems on-board the vehicles. We apply this method on a communication gateway of a bus, through its journey. Finally we present the work done at the standardization level (CEN) in order promote the global architecture vision presented in the thesis

L’hypertension pulmonaire (HTP) est caractérisée par une augmentation progressive des résistances vasculaires pulmonaires, une élévation de la pression artérielle pulmonaire moyenne (≥25 mm Hg) et un déséquilibre entre la production des médiateurs endothéliaux vasoconstricteurs et vasodilatateurs conduisant ainsi à une insuffisance cardiaque droite. Les mimétiques de la prostaglandines (PG)I2 (prostacycline), tels que l'iloprost et le tréprostinil, constituent un des traitements majeurs de l’HTP. L’efficacité des traitements utilisés dans l’http étant évaluée principalement sur l’amélioration de la tolérance à l’effort et la diminution de la dyspnée, il est important d’analyser leurs effets vasodilatateurs artériels mais aussi veineux pulmonaires ainsi que les effets bronchodilatateurs. Ces travaux décrivent les effets, in vitro, de la PGI2, de la PGE2 et de leurs mimétiques sur la réactivité des préparations vasculaires (artères et veines) pulmonaires et bronchiques humaines provenant de patients contrôles ou ayant une HTP. Nous avons caractérisé les différents récepteurs aux prostanoïdes impliqués dans ces réponses. Nos travaux suggèrent que les mimétiques de la PGI2, le treprostinil et l’iloprost, utilisés en clinique, sont d’une part de puissants vasodilatateurs à la fois des artères et des veines pulmonaires et d’autre part, de puissants bronchodilatateurs. Certains mimétiques de la PGI2 (iloprost et tréprostinil) ont des effets vasodilatateurs proportionnels sur les artères et veines pulmonaires. D’autres mimétiques de la PGI2 (béraprost) entraînent une vasodilatation artérielle pulmonaire plus importante que la vasodilatation veineuse. Ceci pourrait entraîner un œdème pulmonaire ou un moindre effet bénéfique sur la correction de la dyspnée. Nous avons mis en évidence une diminution de l’expression des récepteurs IP et DP dans les préparations vasculaires des patients ayant une HTP versus les patients contrôles. Cette diminution est associée avec la réduction de la relaxation des veines pulmonaires induite par le tréprostinil. De même, nous avons montré une diminution de l’expression du récepteur EP4 dans les voies respiratoires des patients ayant une HTP de type 3 ; elle est associée à la réduction de la bronchodilatation induite par les agonistes du récepteur EP4. La correction de cette diminution pourrait être une nouvelle perspective thérapeutique chez ces patients. Nos résultats permettent une meilleure compréhension des effets bénéfiques ou délétères, pharmacologiques et thérapeutiques des mimétiques de la PGI2 déjà utilisées en clinique dans le traitement de l’HTP. A travers la voie PGE2/EP4, nos travaux ouvrent de nouvelles perspectives physiopathologiques et potentiellement thérapeutiques. / Pulmonary hypertension (PH) is characterized by a progressive increase of pulmonary vascular resistance, an increase of mean pulmonary arterial pressure (≥25 mm Hg) and an imbalance between the production of endothelial vasoconstrictor and vasodilator mediators leading to right heart failure. Prostaglandin (PG)I2 (prostacyclin) mimetics, such as iloprost and treprostinil, are major therapeutic tools for this pathology. The efficacy of the treatments used in PH is evaluated primarily on the improvement of exercise tolerance and reduction of dyspnea. For this reason it is important to analyze not only the arterial but also the venous vasodilator effects as well as bronchodilator effects. This thesis describes the in vitro effects of PGI2, PGE2 and their mimetics on the reactivity of human pulmonary vascular (ateries and veins) and bronchial preparations derived from patients with or without PH. We also characterized different prostanoid receptors involved in these responses. Our results suggest that PGI2 mimetics, treprostinil and iloprost, used clinically, are potent vasodilators for both pulmonary arteries and veins and also potent bronchodilators. Some PGI2 mimetics (treprostinil and iloprost) have proportional vasodilatory effects on the pulmonary arteries and veins. Other PGI2 mimetics, such as beraprost, cause greater pulmonary arterial vasodilation than venous vasodilation. This may cause pulmonary edema or less beneficial effects on dyspnea correction. We showed decreased expression of IP and DP1 receptors in vascular preparations of patients with PH versus control patients. This decrease is associated with reduced relaxation response of pulmonary veins induced by treprostinil. Similarly, we demonstrated a reduction in EP4 receptor expression in bronchial preparations of patients with group 3 PH. This down regulation was associated with reduced bronchodilation induced by EP4 agonists. The correction of this down-regulation may be a new therapeutic perspective in these patients. Our results enhance our understanding of the beneficial or deleterious, pharmacological and therapeutic effects of PGI2 mimetics already used clinically in the treatment of PH. Through PGE2/EP4 pathway our work opens new physiopathological and potential therapeutic perspectives.

O presente trabalho trata das estratégias de agregação de tráfego IP nas redes óticas WDM. Utilizar todo um comprimento de onda para transportar um único fluxo de dados numa rede WDM é ineficiente. O problema conhecido como agregação de tráfego consiste na multiplexação de distintos fluxos de tráfego em um mesmo comprimento de onda sobre um caminho ótico. A alocação de múltiplos fluxos de tráfego em comprimentos de onda é realizada por protocolos de controle de admissão, roteamento e designação de comprimento de onda (RWA) e algoritmos de agregação de tráfego. Neste trabalho é simulado o comportamento dinâmico e elástico do tráfego IP diretamente sobre a camada ótica. Com base nos resultados das simulações determinam-se os efeitos da granularidade dos fluxos IP nos parâmetros de desempenho da rede. As topologias utilizadas durante as simulações são das redes NSFNET e Kyatera. É estabelecida também uma correlação entre a granularidade dos fluxos de tráfego e os parâmetros de desempenho da rede. / The present work covers the IP traffic grooming strategies in optical WDM networks. Using an entire wavelength to transport an individual traffic flow in a WDM network is inefficient. The problem known as traffic grooming consists in the multiplexing of different traffic flows in a single wavelength within a lightpath. The allocation of multiple traffic flows is performed by routing and wavelength assignment (RWA) and traffic grooming algorithms. In this work it is simulated the dynamic and elastic behavior of IP traffic directly on top of the optical layer. Based on the simulation results the effects of the IP traffic flow granularity on the network performance parameters are determined. The simulated topologies are the NSFNET and Kyatera. It is also established the correlation between the traffic flow granularity and the network performance parameters.

Esta dissertação descreve os métodos, medidas e análises feitas para otimizar a rede de comunicação de dados do Instituto de Física de São Carlos. As tecnologias e protocolos utilizados na rede são apresentados. Especial atenção é dada a análise do desempenho de VLANs utilizando inicialmente o protocolo LANE no núcleo ATM da rede. Neste caso a rede é composta de switches ATM e ATM-Ethernet. Medidas comparativas foram realizadas com a utilização da tecnologia Fast Ethernet no backbone, que possui uma capacidade de transmissão relativamente próxima da ATM de 155Mbps. Melhores resultados obtidos com a implementação de sub-redes maiores, reduzindo em um numero menor de sub-redes, são discutidos e apresentados. Análises estatísticas baseadas apenas no tempo de resposta da rede são apresentados para avaliar o desempenho das alterações efetuadas nas configurações da rede. Mesmo que o tráfego tenha aumentado muito durante esses anos e que vários serviços tenha sido agregados a esta rede, foi possível adequar o desempenho as novas necessidades beneficiando-se da evolução tecnológica que os equipamentos de rede de dados trouxeram ao IFSC. / This work describes the methods, measures and analyses performed aiming to optimize the data communication network from the Physics Institute of Sao Carlos as well as the technologies and protocols used in the network recently. Special care is given to the analysis of the VLANs performance using, initially, the LANE protocol over ATM which has its core based on pure ATM and ATM-Ethernet switches. Comparative measures had been carried out using a backbone working on a Fast Ethernet technology, which seems to have a very close transmission rate from the ATM 155Mbps. This work also discusses best results acquired with the implementation of larger networks reducing the number of subnetworks, statistical analyses based on time delay of the network in order to evaluate the performance of the changes made on its configuration. Even though the traffic from the Institute has been increased over these years and several services have been added to the network, it was completely possible to adapt the performance to the needs, using the benefits of the technological evolution which the network equipments had brought to the Institute.

O ataque por negaÃÃo de serviÃo ficou conhecido a partir do ano de 1988, tendo se tornado uma grave ameaÃa ao funcionamento das redes de computadores em todo o mundo. Quando essa modalidade de ataque està em curso a vÃtima recebe um incremento tÃo intenso na demanda pelos seus recursos computacionais, que os mesmos podem se tornar indisponÃveis aos usuÃrios. A despeito de existirem outras formas de ataques a redes de computadores, a negaÃÃo-de-serviÃo tem sido alvo de particular interesse da comunidade cientÃfica dedicada no estudo da seguranÃa de redes de computadores. Isto se deve à simplicidade com que este ataque pode ser desferido, aliada ao seu efeito devastador. AlÃm disso, a dificuldade que a vÃtima terà em se defender, dependerà da forma como o ataque se processa, sendo as formas de ataque caracterizadas como âdiretaâ, âindiretaâ, ou âdistribuÃdaâ. Na literatura especializada em seguranÃa existem trabalhos com variadas propostas para a abordagem deste problema, sendo predominante nas mesmas o carÃter de estado-da-arte. A tendÃncia que se acentua nas propostas à a da uniÃo de argumentos computacionais e matemÃticos. Nesta tese sÃo analisados alguns trabalhos que apresentam contribuiÃÃes relevantes para a resoluÃÃo do problema em estudo. Junta-se a esta anÃlise a apresentaÃÃo de uma idÃia original para o tratamento do problema, utilizando conceitos e ferramentas da Teoria das VariÃveis Complexas. Com efeito, atravÃs de um mapeamento do ambiente de taque no espaÃo das variÃveis complexas, desenvolve-se um mÃtodo para a identificaÃÃo do nÃmero IP de um atacante por meio do uso do conceito de ânÃmero de rotaÃÃo de uma trajetÃria ao redor de um pontoâ. Este conceito à uma conseqÃÃncia do âTeorema Integral de Cauchyâ, um dos mais importantes resultados da Teoria das VariÃveis Complexas. / The denial-of-service attack was unveiled in the year of 1988 and became a serious threat to the computer networks to carry on properly, around the world. When this kind of attack is going on the victim suffers so high increment in demanding computational resources, that they may become unavailable to the true users. Despite the fact that there exist other kind of computers network attacks, the denial-of-service attack is the target of a special interest by the scientific community, dedicated to computers network security. This is due to the simplicity in starting the attack, associated with its destructive effect. The difficulty in defending against this attack grows according to it is in a form âdirectâ, âindirectâ, or âdistributedâ. In the specialized literature dealing with security there are papers with varied approaches to this problem and the main feature is the predominant state-ofart. The stressed trend in the arised proposes is the joining of mathematical and computational arguments. In this thesis some papers are analysed with considerable contributions to the problem under study. An original idea dealing with this problem, based in concepts and tools of the Theory of Complex variables, is joined to this analysis. The mapping between the attack environment and the complex variables space is the form by which one may construct a method to determine an attacker IP number, through the use of the âwindind number of a path around a pointâ. This concept is a consequence of the âCauchyâs Integral Theoremâ, one the the most important results in the Theory of complex Variables.

O presente trabalho trata das estratégias de agregação de tráfego IP nas redes óticas WDM. Utilizar todo um comprimento de onda para transportar um único fluxo de dados numa rede WDM é ineficiente. O problema conhecido como agregação de tráfego consiste na multiplexação de distintos fluxos de tráfego em um mesmo comprimento de onda sobre um caminho ótico. A alocação de múltiplos fluxos de tráfego em comprimentos de onda é realizada por protocolos de controle de admissão, roteamento e designação de comprimento de onda (RWA) e algoritmos de agregação de tráfego. Neste trabalho é simulado o comportamento dinâmico e elástico do tráfego IP diretamente sobre a camada ótica. Com base nos resultados das simulações determinam-se os efeitos da granularidade dos fluxos IP nos parâmetros de desempenho da rede. As topologias utilizadas durante as simulações são das redes NSFNET e Kyatera. É estabelecida também uma correlação entre a granularidade dos fluxos de tráfego e os parâmetros de desempenho da rede. / The present work covers the IP traffic grooming strategies in optical WDM networks. Using an entire wavelength to transport an individual traffic flow in a WDM network is inefficient. The problem known as traffic grooming consists in the multiplexing of different traffic flows in a single wavelength within a lightpath. The allocation of multiple traffic flows is performed by routing and wavelength assignment (RWA) and traffic grooming algorithms. In this work it is simulated the dynamic and elastic behavior of IP traffic directly on top of the optical layer. Based on the simulation results the effects of the IP traffic flow granularity on the network performance parameters are determined. The simulated topologies are the NSFNET and Kyatera. It is also established the correlation between the traffic flow granularity and the network performance parameters.

Dans cette thèse, nous proposons différents mécanismes de gestion de la mobilité et de support de qualité de service (QoS) dans les réseaux cellulaires tout-IP. Avant d'entamer nos travaux de recherche, nous examinons et analysons tout d'abord l'architecture des réseaux mobiles tout-IP ainsi que la complexité et les problèmes liés aux performances des protocoles de macro- et micro-mobilité existants. Les résultats de cette analyse seront ensuite exploités pour présenter et discuter nos propositions. L'objectif recherché est d'assurer, au moindre coût, le meilleur support de la mobilité et d'offrir les garanties de QoS exigées par les applications temps réel. Notre solution de base, intitulée ``Micro Mobile MPLS'', repose sur l'intégration du protocole Mobile IP hiérarchique avec le protocole de commutation de labels (MPLS). Outre le support de la QoS, notre architecture est flexible, scalable (résiste au passage à l'échelle) et supporte les modèles Diffserv et Intserv. En effet, les chemins ou LSPs (Label witched Paths) peuvent être établis soit à l'avance par provisioning (on parle dans ce cas de LSPs statiques), soit dynamiquement sur demande (on parle dans ce cas de LSPs dynamiques). Dans un second temps, nous exposons trois variantes protocolaires proposées pour compléter notre solution de base ``Micro Mobile MPLS''. La première variante, intitulée ``FH-Micro Mobile MPLS'', supporte le fast handover pour réduire les perturbations des communications en cours en minimisant le temps de handover. La deuxième variante, intitulée ``FC-Micro Mobile MPLS'', est basée sur une suite de chemins construits dynamiquement pour réduire le coût de signalisation lors des mises à jour de localisation. En effet, en utilisant ce mécanisme, le terminal mobile a la capacité de s'enregistrer auprès de son ancien sous-réseau au lieu du noeud d'entrée du domaine formant ainsi une suite de chemins de tous les sous-réseaux visités. Enfin, la troisième variante protocolaire, intitulée ``MFC-Micro Mobile MPLS'', propose de réduire la charge de signalisation au sein du réseau d'accès en contrôlant dynamiquement le nombre des mises à jour de localisation auprès du noeud d'entrée du domaine. Ceci permet d'assurer une flexibilité et une adaptabilité optimales, en tenant compte des caractéristiques du réseau et de la mobilité des utilisateurs. Tout au long de ce travail, des études de performances, basée sur des analyses théoriques et également sur des simulations ont été réalisées afin d'évaluer l'efficacité de nos propositions. Des modèles de mobilité basés sur des chaînes de Markov sont développés en adoptant des configurations cellulaires à une dimension (1-D) et à deux dimensions (2-D). Les critères de performances utilisés correspondent au coût d'utilisation des liens, au coût de signalisation lors des mises à jour de localisation ou encore coût d'enregistrement, à la latence d'un handover et au taux de perte des paquets. Les résultats de cette analyse ont montré une nette amélioration du délai de handover et du taux de perte des paquets ainsi qu'une réduction importante du coût de signalisation permettant par ailleurs de garantir une bonne qualité de service pour les applications temps réel.