Η παρούσα διπλωματική εργασία παρουσιάζει το πρόβλημα της εξάντλησης των IPv4 διευθύνσεων καθώς και τη διαδικασία μετάβαση στο IPv6. Πιο συγκεκριμένα, παρουσιάζονται τεχνολογίες και τεχνικές που έχουν προταθεί σε διεθνή forum για την μετάβαση από IPv4 σε IPv6 και αφορούν MPLS δίκτυα telecom provider. Στο 5ο κεφάλαιο δημιουργείται ένα περιβάλλον εξομοίωσης δικτυακών συσκευών και προσομοιώνονται βέλτιστες πρακτικές. Πολλοί providers έχουν επενδύσει τα τελευταία χρόνια στην εγκατάσταση IPv4-MPLS για τα δίκτυα κορμού τους. Από μια τέτοια μακροχρόνια επένδυση είναι λογικό μία επιχείρηση να περιμένει οφέλη. Η υποστήριξη IPv6 πάνω από το ήδη υπάρχον IPv4-MPLS θα απέδιδε τα μέγιστα οφέλη για μια τέτοια επιχείρηση. Έτσι μια τέτοια μετάβαση αποτελεί στρατηγική κίνηση που ουσιαστικά σκοπεύει στην αύξηση των κερδών του καθώς και την προετοιμασία του για το μέλλον. / This thesis aims to present the issue of constantly-decreasing available IPv4 addresses as well as the related transition process to IPv6, before the fully elimination of IPv4. More specifically, in this thesis there will be presented technologies and techniques which have been recommended in several international forums in relation to transition from IPv4 to IPv6 and which concern the MPLS networks for telecom providers. In the fifth chapter, an emulation environment for network devices will be “created”, through which some of the most appropriate transition implementation practices will be simulated. During the last years several providers have invested in installing IPv4-MPLS for their core networks. From such a long-term investment is sensible that one business expects profits. According to Chapter 5, the transition to IPv6 in conjunction with the full utilization of existing IPv4-MPLS equipment would have significant benefits for any business decided to proceed with this option. In particular, such a transition (from IPv4 to IPv6) could be part of a business strategy since not only contributes to the technological upgrading of a company’s systems and the production of more reliable services, but also to create synergies and economies of scale.

Made available in DSpace on 2014-06-12T15:58:15Z (GMT). No. of bitstreams: 2 arquivo3316_1.pdf: 5730549 bytes, checksum: cff2a33fe304e845301e541fe55d0dda (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2009 / A crescente demanda de tráfego e o dinamismo do mercado de Redes de Computadores, necessitando a cada dia mais de integração entre serviços (voz, vídeo e dados), fazem com que os ISPs (Internet Service Providers) estejam sempre em constante atualização, visando acompanhar as tendências desse mercado tecnológico, com o objetivo não só de prover uma boa qualidade nos serviços ofertados, mas também de evitar uma rápida obsolescência dos equipamentos adquiridos. Nesse contexto, a tecnologia MPLS (MultiProtocol Label Switching) é indicada para prover evolução, otimização e flexibilidade aos backbones atuais, se mostrando como uma tecnologia emergente a ser empregada nos ISPs, como uma alternativa de suporte à qualidade de serviço (QoS), engenharia de tráfego (TE) e redes virtuais privadas (VPNs), assegurando escalabilidade e segurança, ampliando o escopo de serviços agregados. A principal motivação e contribuição deste trabalho é mostrar o benefício obtido com a flexibilidade e otimização do backbone do SERPRO (Serviço Federal de Processamento de Dados), ao fazer uso da tecnologia MPLS, tornando-o muito mais inteligente, devido à sua capacidade de efetuar o roteamento dos pacotes baseado em rótulos, com isso acelerando o processo de transmissão das informações, e prover alguns serviços agregados, tais como: VPNs (Virtual Private Networks), QoS (Quality of Service), TE (Traffic Engineering) e AToM (Any Transport over MPLS). Nesse trabalho é proposto um ambiente de teste, desenvolvido para esta dissertação, com o objetivo de apresentar experimentos comprobatórios de alguns serviços utilizados pela tecnologia MPLS citados acima, e com isso fazer uma análise qualitativa dos mesmos. A aplicabilidade desse ambiente foi testada no emulador, de domínio público, Dynagen/Dynamips, sendo os resultados apresentados neste trabalho

O principal objetivo deste trabalho é analisar a arquitetura das redes ópticas, discutir o estado da arte dos protocolos necessários ao seu desenvolvimento, e avaliar os vários esforços empregados para a padronização destas por diferentes instituições. Conceitualmente, redes ópticas são aquelas nas quais a tecnologia dominante na camada física é a fibra óptica. Tais redes originaram-se no início dos anos 80 com a utilização dos cabos de fibras ópticas monomodo, tendo evoluído com a introdução de uma nova base tecnológica composta por novos tipos de fibras ópticas, amplificadores ópticos, sistemas DWDM e componentes ópticos, como multiplexadores e demultiplexadores add/drop e cross-connects ópticos. O desenvolvimento destes componentes possibilitará a evolução dos simples enlaces DWDM ponto a ponto para a rede totalmente óptica. Neste trabalho é analisado como as aplicações interagirão com esta camada física. Tal interação tem provado ser um desafio dentro da atual arquitetura das redes de dados, no intuito de disponibilizar soluções que habilitem o transporte de um grande volume de tráfego de forma eficiente. Neste sentido é analisado o emprego de tecnologias como o MPLS (Multiprotocol Label Switching) e sua evolução, o Generalized MPLS (GMPLS). Finalmente apresenta-se a versão do ITU para arquitetura de redes ópticas, e a conseqüente inserção do GMPLS nesta padronização / The main objective of this work is to analyze the evolution trends for the architecture of the optical networks, discuss the state of the art protocols required for its development and evaluate the various efforts being carried out by different institutions in order to achieve standardization. In this context, optical networks are those in which the dominant technology in the physical layer is the optical fiber. Such networks arose in the early eighties with the use of the monomodo fiber optic cables and were further developed with the introduction of a new technological base composed by new types optical fibers, optical amplifiers, DWDM systems and optical components such as add/drop multiplexers and optical cross-connects. The introduction of these components will make possible the evolution from the simple point-to-point DWDM connections to the all optical networks. In this work we analyze how the applications will interact with this physical layer. Such interaction has been proving to be a challenge within the framework for the current architecture of data networks, aiming at offering solutions to enable the transport of a great volume of traffic in an efficient manner. With this goal in mind, the use of technologies such as MPLS (Multiprotocol Label Switching) and its evolution, the Generalized MPLS (GMPLS) is discussed. Finally, we present the ITU version for the architecture optical networks, addressing its merging with the GMPLS

O principal objetivo deste trabalho é analisar a arquitetura das redes ópticas, discutir o estado da arte dos protocolos necessários ao seu desenvolvimento, e avaliar os vários esforços empregados para a padronização destas por diferentes instituições. Conceitualmente, redes ópticas são aquelas nas quais a tecnologia dominante na camada física é a fibra óptica. Tais redes originaram-se no início dos anos 80 com a utilização dos cabos de fibras ópticas monomodo, tendo evoluído com a introdução de uma nova base tecnológica composta por novos tipos de fibras ópticas, amplificadores ópticos, sistemas DWDM e componentes ópticos, como multiplexadores e demultiplexadores add/drop e cross-connects ópticos. O desenvolvimento destes componentes possibilitará a evolução dos simples enlaces DWDM ponto a ponto para a rede totalmente óptica. Neste trabalho é analisado como as aplicações interagirão com esta camada física. Tal interação tem provado ser um desafio dentro da atual arquitetura das redes de dados, no intuito de disponibilizar soluções que habilitem o transporte de um grande volume de tráfego de forma eficiente. Neste sentido é analisado o emprego de tecnologias como o MPLS (Multiprotocol Label Switching) e sua evolução, o Generalized MPLS (GMPLS). Finalmente apresenta-se a versão do ITU para arquitetura de redes ópticas, e a conseqüente inserção do GMPLS nesta padronização / The main objective of this work is to analyze the evolution trends for the architecture of the optical networks, discuss the state of the art protocols required for its development and evaluate the various efforts being carried out by different institutions in order to achieve standardization. In this context, optical networks are those in which the dominant technology in the physical layer is the optical fiber. Such networks arose in the early eighties with the use of the monomodo fiber optic cables and were further developed with the introduction of a new technological base composed by new types optical fibers, optical amplifiers, DWDM systems and optical components such as add/drop multiplexers and optical cross-connects. The introduction of these components will make possible the evolution from the simple point-to-point DWDM connections to the all optical networks. In this work we analyze how the applications will interact with this physical layer. Such interaction has been proving to be a challenge within the framework for the current architecture of data networks, aiming at offering solutions to enable the transport of a great volume of traffic in an efficient manner. With this goal in mind, the use of technologies such as MPLS (Multiprotocol Label Switching) and its evolution, the Generalized MPLS (GMPLS) is discussed. Finally, we present the ITU version for the architecture optical networks, addressing its merging with the GMPLS

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

Made available in DSpace on 2014-06-12T17:35:33Z (GMT). No. of bitstreams: 2 arquivo2470_1.pdf: 6699219 bytes, checksum: f7ab13c2c0f61e4dfa1c822d8756767a (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2011 / O aumento da demanda pela utilização de novos serviços de valor agregado sobre as infraestruturas de rede baseadas no protocolo IP (Internet Protocol), tais como voz e vídeo, contribui para que as operadoras de telecomunicações enfrentem um grande desafio para prover um backbone estável, escalável e otimizado, para atender satisfatoriamente essas novas expectativas de tráfego dos seus clientes. As empresas de telecomunicações buscam uma rede com uma maior disponibilidade e menor custo. A tecnologia MPLS (Multi-Protocol Label Switching) é indicada para prover evolução, otimização e flexibilidade aos backbones atuais, mostrando-se uma tecnologia emergente a ser empregada nessas redes. O novo paradigma de transporte baseado no MPLS permite as operadoras de telecomunicações construírem, sobre as infraestruturas IP, ATM (Asynchronous Transfer Mode) e Frame Relay, um conjunto de soluções criativas e flexíveis para suprir essa nova demanda de serviços. Dentre esses serviços, destacam-se a oferta de Internet e VPN (Virtual Private Network) na rede da operadora apoiada pela implementação de uma arquitetura com QoS (Quality of Service) e satisfazendo os requisitos de TE (Traffic Engineering) sobre MPLS. Esta dissertação apresenta a engenharia de tráfego aplicada a backbone IP MPLS de uma operadora de telecomunicações, com a aplicação prática do MPLS-TE (Multi-Protocol Label Switching Traffic Engineering), analisando e otimizando os recursos de transmissão com caminhos redundantes não utilizados pelo protocolo OSPF (Open Shortest Path First)

Made available in DSpace on 2014-06-12T17:35:55Z (GMT). No. of bitstreams: 2 arquivo2517_1.pdf: 1387760 bytes, checksum: 2b6b3a343f1180754d0c40a00da722bc (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2009 / É comum associar a telefonia IP somente a aplicativos tais como: Skype, Gizmo e MSN. Entretanto um segmento muito mais expressivo na área de telefonia IP começa a despontar: as redes de alto tráfego de voz e com exigência de altíssima disponibilidade e qualidade de serviço. Há hoje o interesse real e crescente em se reduzir custos com equipamentos e com ligações telefônicas. Esta dissertação contempla a análise do tráfego de voz através de enlaces Multiprotocol Label Switching (MPLS) buscando-se boa qualidade de voz e a disponibilidade de 99,999%, já alcançada pela Rede Pública de Telefonia (PSTN). As redes MPLS tornam possível a interoperabilidade entre o roteamento de pacotes e a comutação de circuitos, além de reduzir o consumo de recursos dos roteadores permitindo obter um melhor desempenho da rede. Os experimentos efetuados no desenvolvimento desta dissertação indicam que pode-se obter a disponibilidade e qualidade de serviço necessárias para substituir as soluções convencionais de telefonia, utilizando-se o protocolo IP para o tráfego de voz sobre uma rede MPLS

MPLS (Multiprotocol Label Switching) VPNs (Virtual private network) are new alternatives to private WANs (Wide area network). They are gaining popularity in industry day by day. Enterprise customers are moving to service providers that offer MPLS VPNs. The main reason for this shifting is the capability of MPLS VPN to provide built in security features and any-to-any connectivity. QoS (Quality of service) is the most important element for enterprise networks. Enterprise network have video, audio and data traffic over a single network infrastructure.In this thesis we will investigate QoS parameters (e.g. delay, jitter and packet loss) over MPLS VPNs environment. It will help the service providers and enterprise network customers to maintain QoS for voice, video and data traffic over MPLS VPNs environment.To achieve consistent end-to-end QoS, the service provider and the enterprise customer must work closely together and share the same policies to implement because service provider participates in customer routing in MPLS VPN environment. We will use the DiffServ (Differentiated services) QoS model over MPLS VPN network. We will use a six class model for service provider network and enterprise customer network to achieve end-to- end service quality.In the last part we will make tests of end-to-end traffic delay, jitter and packet loss. We will compare the results of delay, jitter and packet loss with and without the DiffServ QoS model in an MPLS VPNs environment. It will be clear in the results that without using DiffServ QoS model delay, jitter and packet loss are increasing as the traffic increases on the network. With a DiffServ enabled network, the increase of traffic over network will not affect delay, jitter and packet loss and provide constant level of service quality.

Reliable routing using alternate paths is investigated in this dissertation. We propose precalculated alternate paths as a method for fast recovery from link and node failures in IP networks. We demonstrate that path switching time, and thus failure recovery time are, as expected, considerably faster than the standard method of recalculating a new path on the fly. However, to be effective, the alternate paths should share a minimal set of links and nodes - preferably none - with the failed path. As shared links are considered in this work, we give a reliability model for this situation (non-disjoint alternate paths) and develop estimates of reliability as a function of the number of shared links. Alternate path finding algorithms to calculate suitable alternate paths subject to predefined constraints are also developed. Implementation of these techniques for improving routing reliability is shown to be straightforward for explicit routing protocols such as Multi-Protocol Label Switching (MPLS) with Explicit Routing mode. This mode is expected to be the protocol of choice for applications requiring guaranteed Quality of Service (QoS) carried on the coming generation of wavelength-switched networks (Internet II, CA Net III, etc.) We propose a Reliable MPLS (R-MPLS) protocol by applying alternate path routing to MPLS, using our new algorithms to precalculate appropriate alternate paths. Simulation results show that R-MPLS can achieve fast recovery from failures. We also address reliability issues for the problem of optimal Service Level Agreement (SLA) admission control. To achieve reliable admission control, we apply alternate path routing to an existing SLA-based admission controller called SLAOpt. In the existing Utility Model, SLA admission control is mapped to the Multiple-Choice Multi-Dimension Knapsack Problem (MMKP), where the aim is to maximize system utility (i.e., revenue). However, SLAOpt is static in terms of network topology and does not consider reliability. Motivated by this, we propose a Reliable SLAOpt (R-SLAOpt), in which utility optimization is subject to the additional constraint of reliability. A new algorithm was also developed to calculate multiple groups of alternate paths that meet the desired QoS demands and reliability requirement. After QoS adaptation, R-SLAOpt selects an appropriate path group containing two or three paths for each admitted session and performs resource reservation on all paths in the group. In the event of node or link failure, a session can be quickly switched to one of the alternate paths, maintaining the guaranteed QoS without having to run the full admission algorithm again. In this way, we have obtained a unified treatment of routing reliability and optimal SLA admission control. Finally, simulations are presented which investigate R-SLAOpt's impact on system performance and the gains made in reliability. / Graduate

La superposition de topologies virtuelles à la topologie physique d'un réseau est un des principaux mécanismes de l'ingénierie de trafic. Soit un réseau physique d'une certaine topologie et capacité fixées et une matrice de trafic à véhiculer, il s'agit trouver une topologie logique permettant de mapper de manière optimale la matrice de trafic sur le réseau physique. Lors de l'évolution de la matrice de trafic sur des échelles de temps longues, il faudra agir sur le layout. La première contribution concerne la définition de fonctions de coût mieux adaptées à la réalité d'un opérateur, la deuxième contribution concerne la prise en compte du coût de changement du layout. Il s'avère intéressant d'un point de vue opérateur de réduire la complexité du layout, mesurée comme une fonction du nombre de chemins virtuels. Nous avons donc formulé divers problèmes de minimisation de la complexité du layout sous des contraintes de QoS. Il s'agit d'une modélisation réaliste mais qui engendre des modèles difficiles à résoudre. Nous avons développés des heuristiques qui permet de trouver des solutions approchées pour des réseaux de grande taille. Nous avons montré que la complexité des layouts peut être significativement réduite en comparaison avec celle obtenue suite à l'optimisation des fonctions de coût classiques. Le changement du layout implique d'une part un coût d'opération et d'autre part peut engendrer des coupures de service qui affecteront directement le coût d'opération. Nous avons formulé une famille de problèmes prenant en compte le coût de reconfiguration du layout. L'une des heuristiques citées a été adaptée pour analyser ces nouveaux problèmes.