Internet traffic has surpassed voice traffic and is dominating in transmission networks. The Internet Protocol (IP) is now being used to encapsulate various kinds of services. The new services have different requirements than the initial type of traffic that was carried by the Internet network and IP. Interactive services such as voice and video require paths than can guarantee some bandwidth level, minimum delay and jitter. In addition service providers need to be able to improve the performance of their networks by having an ability to steer the traffic along the less congested links or paths, thus balancing the load in a uniform way as a mechanism to provide differentiated service quality. This needs to be provided not only within their domains but also along paths that might traverse more than one domain. For this to be possible changes have been proposed and some are being applied to provide quality of service (QoS) and traffic engineering (TE) within and between domains. Because data networks now carry critical data and there are new technologies that enable providers to carry huge amount of traffic, it is important to have mechanisms to safeguard against failures that can render the network unavailable. In this thesis we propose and develop mechanisms to enable interdomain traffic engineering as well as to speed up the restoration time in optical transport networks. We propose a mechanism, called abstracted path information, that enable peering entities to exchange just enough information to engage in QoS and TE operations without divulging all the information about the internal design of the network. We also extend BGP to carry the abstracted information. Our simulations show that BGP could still deliver the same performance with the abstracted information. In this thesis we also develop a method of classifying failures of links or paths. To improve the restoration time we propose that common failures be classified and assigned error type numbers and we develop a mechanism for interlayer communication and faster processing of signalling messages that are used to carry notification signals. Additionally we develop a mechanism of exchanging the failure information between layers through the use of service primitives; that way we can speed up the restoration process. Finally we simulate the developed mechanism for a 24 node Pan American optical transport network. / <p>QC 20100913</p>

The Internet at the interdomain level is a complex network of approximately 50,000 Autonomous Systems (ASes). ASes interconnect through two types of links: (a) transit (customer-provider) and (b) peering links. Recent studies have shown that despite being optional for most ASes, a rich and dynamic peering fabric exists among ASes. Peering has also grown as one of the main instruments for catching up with asymmetric traffic due to CDNs, online video traffic, performance requirements, etc. Moreover, peering has been in the spotlight recently because of peering conflicts between major ISPs and Content Providers. Such conflicts have led to calls for intervention by communication regulators and legislation at the highest levels of government. Peering disputes have also sometimes resulted in partitioning of the Internet. Despite the broad interest and intense debate about peering, several fundamental questions remain elusive. The objective of this thesis is to study peering from a techno-economics perspective. We explore the following questions: 1- What are the main sources of complexity in Internet peering that defy the development of an automated approach to assess peering relationships? 2- What is the current state of the peering ecosystem, e.g., which categories of ASes are more inclined towards peering? What are the most popular peering strategies among ASes in the Internet? 3- What can we say about the economics of contemporary peering practices, e.g., what is the impact of using different peering traffic ratios as a strategy to choose peers? Is the general notion that peering saves network costs, always valid? 4- Can we propose novel methods for peering that result in more stable and fair peering interconnections? We have used game-theoretic modeling, large-scale computational agent-based modeling, and analysis of publicly available peering data to answer the above questions. The main contributions of this thesis include: 1- Identification of fundamental complexities underlying the evaluation of peers and formation of stable peering links in the interdomain network. 2- An empirical study of the state of the peering ecosystem from August 2010 to August 2013. 3- Development of a large-scale agent-based computational model to study the formation and evolution of Internet peering interconnections. 4- A plausible explanation for the gravitation of Internet transit providers towards Open peering and a prediction of its future consequences. 5- We propose a variant of the Open peering policy and a new policy based on cost-benefit analysis to replace the contemporary simplistic policies.

Submitted by Rafael Santana (rafael.silvasantana@ufpe.br) on 2017-08-31T18:59:35Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Tese_ncq_BibCentral.pdf: 1225157 bytes, checksum: 95c64f7539810675d5239fa417712bf2 (MD5) / Made available in DSpace on 2017-08-31T18:59:35Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Tese_ncq_BibCentral.pdf: 1225157 bytes, checksum: 95c64f7539810675d5239fa417712bf2 (MD5) Previous issue date: 2016-03-04 / A continuidade de sessões de comunicação entre sistemas finais, denominados nós, sobre redes móveis heterogêneas mediante handover tem sido objeto de estudo de pesquisas recentes. A ampla difusão de aplicativos multimídia para dispositivos móveis, permitindo a interação entre usuários que se deslocam em uma rede móvel, tornam esse problema ainda mais relevante e atual. No âmbito da mobilidade IP, alguns dos principais desafios envolvem aliar interoperabilidade entre tecnologias de acesso e baixa latência de handover, além de permitir a transição entre redes de domínios diferentes de forma transparente. O protocolo Proxy MIP versão 6 (PMIPv6) torna locais as operações de gerenciamento de mobilidade de modo a reduzir o overhead de comunicação em relação ao Mobile IP (MIP). Entretanto, o consequente isolamento da gerência de mobilidade ao domínio local impede que a transição entre diferentes domínios ocorra de forma transparente ao usuário. A presente tese apresenta o Clustered PMIPv6 (CPMIPv6) como uma abordagem intradomínio e interdomínio de baixo custo e latência para a camada de rede baseada no Protocolo PMIPv6. Essa abordagem consiste em utilizar gerenciamento de mobilidade distribuído como forma de compartilhar e antecipar informações de nós móveis à entidadeâncora de cada domínio. Para tal, um cluster é formado por essas entidades-âncora e a comunicação entre elas ocorre por meio de um protocolo P2P. Esse gerenciamento torna a obtenção de informações dos nós móveis simplificada em handovers interdomínios futuros. O caráter distribuído do CPMIPv6 associado ao mínimo de acréscimo de mensagens de sinalização além daquelas existentes no PMIPv6 permite manter a infraestrutura da rede original, sem introduzir entidades centralizadoras. Comparações entre soluções do Estado da Arte e o CPMIPv6 são realizadas por meio de modelagem e simulação. Com auxílio do simulador NS-3, um subconjunto dessas soluções são avaliadas em um cenário básico com baixo número de usuários e de redes disponíveis. Os resultados de experimentos utilizando modelagem executados em cenários com alta densidade de nós indicam que o CPMIPv6 obteve custo de sinalização ao menos 12% menor, latência no mínimo 16% inferior e perda de pacotes ao menos 16% menor. Ademais, o CPMIPv6 obtém goodput superior às demais abordagens. Ambos experimentos confirmam o CPMIPv6 como a abordagem intradomínio e interdomínio com melhor desempenho nos cenários avaliados. O CPMIPv6 é um importante salto na evolução dos sistemas de comunicações móveis extrapolando as fronteiras das tecnologias de enlace e limites de domínio sem perder as vantagens da comunicação no âmbito local. / Communication sessions continuity among wireless devices during handover in heterogeneous networks have been studied in recent research. The evolution and widespread multimedia applications for mobile gadgets make that problem even more relevant. Some of the main challenges in IP mobility include associating access technologies interoperability, low handover latency, and seamless handover among different domains. Proxy MIP version 6 (PMIPv6) protocol aims at reducing signaling overhead in comparison to Mobile IP (MIP) making local the management operations. However, that local management prevents the possibility of seamless interdomain handover. This thesis presents Clustered PMIPv6 (CPMIPv6) as a low-cost and low-latency approach for intradomain and interdomain handover in the network layer based on PMIPv6. That approach consists in using distributed mobility management as a mean to share and anticipate mobile nodes information to anchor entities in each domain. In order to achieve this, domain entities from each domain forms a cluster and uses a P2P protocol for communication. That management simplifies mobile nodes information gathering used in future interdomain handovers. CPMIPv6 distributed feature associated to a minimum set of additional signaling messages to PMIPv6 allows to maintain the original networks infrastructure without introducing centralized entities. Comparisons among state of the art approaches and CPMIPv6 are made by means of analytical modeling and simulation. Simulations were run with the NS- 3 network simulator with a subset of the approaches in a small scenario with low number of nodes and available networks. Modeling results in scenarios with high node densities have shown that CPMIPv6 reduced cost in at least 12%, reduced latency at least in 16%, and caused at least 16% reduction on packet loss. CPMIPv6 additionally obtained better goodput values. Both experiments confirmed CPMIPv6 as the best interdomain approach in the selected scenarios. Thus, CPMIPv6 is an important leap to the mobile communication systems evolution going beyond link-layer technologies and domain frontiers without losing the advantages of local signaling.

Interdomain traffic engineering (TE) controls the flow of traffic between autonomous systems (ASes) to achieve performance goals under various resource constraints. Interdomain TE can be categorized into ingress TE and egress TE, which aim to control the ingress and egress traffic flow in a network, respectively. Most interdomain TE techniques are based on BGP, which was not designed to support performance based routing. Hence even though some basic interdomain TE techniques are widely deployed, their overall effectiveness and impact on interdomain traffic are not well understood. Furthermore, systematic practices for deploying these techniques have yet to be developed. In this thesis, we explore these open issues for both ingress and egress TE. We first focus on the AS-Path prepending technique in interdomain ingress TE. We design a polynomial algorithm that takes network settings as input and produces the optimal prepending at each ingress link. We also develop methods to measure the inputs of the optimal algorithm by leveraging widely available looking glass severs and evaluate the errors of such measurement. We further propose an algorithm, based on this optimal algorithm, that is robust to input errors. We then focus on Intelligent Routing Control (IRC) systems often used at multihomed networks for egress interdomain TE. To address the possible traffic oscillation problem caused by multiple IRC systems, we design a class of randomized IRC algorithms. Through simulations, we show that the proposed algorithms can effectively mitigate oscillations. We also show that IRC systems using randomized path switching algorithms perform better than those switching path deterministically, when both types of IRC systems co-exist. To further understand the performance impact of IRC systems, we next focus on the performance of applications, such as TCP connections. We study the synergistic and antagonistic interactions between IRC and TCP connections, through a simple dual-feedback model. We first examine the impact of sudden RTT and available bandwidth changes in TCP connection. We then examine the effect of IRC measurement delays on closed loop traffic. We also show the conditions under which IRC is beneficial under various path impairment models.

Internet est le résultat de l’interaction des milliers de réseaux qui le composent. On les appelle les systèmes autonomes, chacun est identifié par un numéro unique (ASN). Les politiques de routage des AS et les accords économiques restent confidentiels normalement. Afin de mieux comprendre le routage dans l’Internet, les chercheurs modèlent le routage. Le model souvent utilisé c’est la représentation d’un AS par un atome. Nous présentons trois contributions dans ce travail. On montre d’abord des contradictions entre les décisions de routage réellement faites et les inférences à partir d’un ensemble d’hypothèses souvent utilisées. 70% des instances de ce qu’on appelle «plusieurs sorties» montrent des incohérences. Le routage est appelé à plusieurs sorties quand un AS utilise simultanément plusieurs routes vers la même destination, et chacune passe par un AS différent. Notre deuxième contribution est sur les routes BGP erronées causées par des mauvaises configurations liées à la transaction de la représentation des ASNs de 16-bits à 32-bits et l’utilisation d’AS23456 pour assurer la compatibilité. Nous montrons que tels erreurs sont encore présentes, ensuite nous montrons les effets des routes qui contiennent AS23456 sur les travaux qui emploient ces routes. Notre dernière contribution concerne les dynamiques de de routage dans l’Internet. Nous proposons une méthode pour quantifier ces dynamiques dans chaque AS afin d’en extraire ceux les plus dynamiques. Ensuite, on se concentre sur l’AS Level 3, l’AS le plus dynamique. Nous expliquons que la raison pour ce grand nombre de dynamique c’est l’équilibration de charge entre des routeurs qui avait plusieurs liens physiques. / Internet is the result of interaction of the thousands of networks that compose it. Each of them is called an autonomous system (AS) and has a unique number (ASN). Routing policies of ASes and business agreements remain in most cases confidential. To understand Internet routing, researchers use routing models. A large family of models represents an AS as an atomic structure. We make in this work three contributions. We look first on a set of commonly made assumptions to show using what we call multi-exit routing contradictions in routing decisions between real routing observed in publicly available measurements and that inferred from the assumptions. Sometimes, more than 70% of multi-exit instances show incoherencies. Multi-exit routing happens when an AS uses simultaneously different routes to a destination, each passing through a different AS. Our second contribution concerns erroneous BGP routes due to misconfigurations in BGP routers related to AS_TRANS, the solution introduced to assure the compatibility with old BGP routers when the change was made to represent ASNs on 32-bits instead of 16-bits. We show that such errors are indeed present, then we show how they can affect work making use of routes carrying this ASN. Our last contribution concerns routing dynamics in the Internet. We propose a method to quantity routing dynamics in each AS, then we look on ASes that have a large proportion of dynamics. After that, we focus on the AS Level 3, one of the ASes that we observe to be most dynamic. We explain that one of the reasons of a large part of the observed dynamics is load balancing between routers that have multiple physical links between each of them.

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.

Made available in DSpace on 2015-04-11T14:02:50Z (GMT). No. of bitstreams: 1 ricardo.pdf: 1126811 bytes, checksum: 85736cdaf1e7cf53e93c63df8abb6b16 (MD5) Previous issue date: 2013-07-29 / CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico / The Internet is organized on network groups managed by administrative domains known as Autonomous Systems (ASes). Each AS employs its own routing policies and has autonomy in comparison to other ASes. The comunication and coordination between these ASes is made possible by the interdomain routing protocol. The Border Gateway Protocol (BGP)is the interdomain routing protocol currently used on Internet. However, the Internet s interdomain routing architecture has undergone only minor changes since its inception. It presents issues difficult to solve, because of the barrier to deploy new features, the hardness to understand its behavior and dynamics, and complexity to identify and correct faults. The deployment on Internet architecture is a tough task, because the need to deploy it directly on routers. Besides that, there is a requirement of global acceptance of new protocols and modifications. We observed that Software Defined Networking (SDN) could be used to provide innovation on interdomain routing, but it lacked mechanisms support this approach. SDN is an emerging paradigm composed by a data plane, a control plane, and an open protocol. On this work we present a mechanism able to perform interdomain routing with domains that deploys SDN paradigm, called Inter-SDN Routing Component. We point out the main issues on current interdomain routing, describes the Inter-SDN component, its behavior, and its experimental evaluation. Besides that, we show how prototyping and building of an interdomain mechanism on SDN are tasks relatively simple, and explain how our solution takes advantage of the SDN features to address the issues of the interdomain routing. / A Internet está organizada em grupos de redes que são gerenciados por domínios ad- ministrativos conhecidos como Sistemas Autônomos (ASes Autonomous Systems). Cada AS emprega suas próprias políticas de roteamento e tem autonomia em relação a outros ASes. A comunicação e coordenação entre estes ASes acontece por meio do protocolo de roteamento interdomínio. O Protocolo de Roteamento de Borda (BGP Border Gateway Protocol) é o protocolo de roteamento interdomínio atualmente utilizado na Internet. Entretanto, a arquitetura do roteamento interdomínio da Internet tem sofrido poucas mudanças desde sua criação. Ela apresenta problemas complexos de serem resolvidos, devido à dificuldade para a implantação de novas soluções, à dificuldade de entender seu comportamento e dinâmica, e à complexidade de identificar e corrigir falhas. A implantação de novas funcionalidades na arquitetura da Internet é uma tarefa difícil, devido à necessidade de manipular diretamente todos os roteadores. Além disso, é necessário aceitação global de novos protocolos e modificações nos existentes. Nós observamos que a abordagem Redes Definidas por Software (SDN Software-Defined Networking) poderia ser usada para prover inovação no roteamento interdomínio, mas que faltavam mecanismos para suportar esse tipo de roteamento. Neste trabalho, nós apresentamos um mecanismo capaz de realizar o roteamento interdomínio entre domínios que utilizam o paradigma SDN, chamado Inter-SDN. Nós ressaltamos os principais problemas no modelo atual de roteamento interdomínio, descrevemos o componente Inter-SDN, seu comportamento, e apresentamos uma análise experimental. Além disso, nós mostramos como o projeto e a construção de um mecanismo de roteamento interdomínio em SDN são tarefas relativamente simples, e explicamos como nossa solução utiliza as vantagens do SDN para resolver problemas do roteamento interdomínio.

Providing end-to-end quality-assured services implies many challenges, which go beyond technical ones, involving as well economic and even cultural or political issues. In this thesis we first focus on a technical problem and then intent a more holistic regard to the whole problem, considering at the same time Network Service Providers (NSPs), stakeholders and buyers' behaviour and satisfaction. One of the most important problems when deploying interdomain path selection with Quality of Service (QoS) requirements is being able to rely the computations on metrics that hold for a long period of time. Our proposal for solving that problem is to compute bounds on the metrics, taking into account the uncertainty on the traffic demands. We then move to a NSP-alliance scenario, where we propose a complete framework for selling interdomain quality-assured services, and subsequently distributing revenues. At the end of the thesis we adopt a more holistic approach and consider the interactions with the monitoring plane and the buyers' behaviour. We propose a simple pricing scheme and study it in detail, in order to use QoS monitoring information as feedback to the business plane, with the ultimate objective of improving the seller's revenue.

Orientador: Mauricio Ferreira Magalhães, Edmundo Roberto Mauro Madeira / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-08T02:00:59Z (GMT). No. of bitstreams: 1 Verdi_FabioLuciano_D.pdf: 3027740 bytes, checksum: 444aae1c448c43278addd0d412181602 (MD5) Previous issue date: 2006 / Resumo: Nos últimos anos têm-se discutido uma maneira para envio de fluxos de pacotes entre domínios que leve em consideração aspectos relacionados com a qualidade de serviço de rede (banda, atraso, etc.). Entretanto, as soluções até agora apresentadas dependem de extensões que precisam ser feitas principalmente nos protocolos de roteamento entre domínios para suportar a distribuição de informações de engenharia de tráfego. Porém, tais extensões dependem de longos processos de padronização que, muitas vezes, apesar de profundas discussões, não conseguem efetivamente definir um padrão. Isto tem ocorrido nas redes IPs onde extensões ao BGP (Border Gateway Protocol) para distribuição de informações de engenharia de tráfego têm sido propostas, porém, nunca colocadas em prática. Recentemente, a mesma discussão surgiu nos cenários envolvendo redes ópticas para estabelecimento de conexões entre domínios. Esta tese apresenta uma alternativa em relação aos processos de padronização que propõem extensões aos protocolos para que os mesmos suportem o provisionamento de serviços entre domínios. Especificamente, a arquitetura para provisionamento e gerência de serviços entre domínios ópticos age de forma independente do plano de controle, ou seja, a proposta apresentada neste trabalho não depende de extensões aos protocolos usados atualmente no roteamento e sinalização entre domínios. A arquitetura apresentada nesta tese cria uma camada de serviços que facilita a interação entre diferentes domínios administrativos. Todas as interações para troca de informações de roteamento e estabelecimento de conexões são feitas na camada de serviços. Internamente a cada domínio, os caminhos de luz são estabelecidos usando tecnologias locais tais como a arquitetura GMPLS (Generalized Multiprotocol Label Switching) ou ASON (Automatic Switched Optical Network). Porém, o provisionamento de serviços entre domínios é realizado não pelo plano de controle, mas sim pelo plano de serviços. Embora o foco da tese seja o provisionamento de serviços entre domínios, a arquitetura suporta também o provisionamento de serviços intra domínios. Os serviços de conexões e VPNs (Virtual Private Networks) dentro de um domínio e entre domínios administrativos diferentes serão oferecidos. A arquitetura é baseada no modelo TMN (Telecommunications Management Network), principalmente no que se refere às camadas do modelo e à nomenclatura. Usamos a tecnologiaWeb Services para implementação da arquitetura e uma análise de tal tecnologia foi realizada a fim de avaliarmos o seu uso para estabelecimento de serviços entre domínios. Os resultados apresentados indicam que o provisionamento de serviços realizado através da camada de serviços facilita e flexibiliza as interações entre domínios oferecendo aos provedores uma novo mecanismo para suporte a estas interações / Abstract: In the last few years it has been discussed a way for sending interdomain packet flows taking into account some aspects related to the network quality of service (bandwidth, delay, etc.). However, the solutions presented so far depend on the extensions that need to be done mainly in the interdomain routing protocols to support the distribution of traffic engineering information. Nevertheless, such extensions depend on long-process of standardization that, in many cases, does not reach a consensus and a standard is not effectively defined. An example of this is that in IP networks the proposed extensions for the BGP (Border Gateway Protocol) to support the distribution of traffic engineering information were not put into practice until now. Recently, the same discussion came through in the optical network scenario. This thesis presents an alternative to standardization processes. We propose an architecture for provisioning and management of interdomain services in optical networks. Such architecture acts independent of the control plane and does not depend on the protocol extensions that are needed to support interdomain routing and signaling. The architecture has a service layer by which all the interactions between different optical domains are done. Within each domain, the lightpaths are established using local solutions such as GMPLS (Generalized Multiprotocol Label Switching) or ASON (Automatic Switched Optical Network). However, the provisioning of interdomain services is not done in the control plane. Instead, it is done in the services layer. Although the focus of this thesis is on the provisioning of interdomain services, the architecture also supports the establishment of intradomain services. We are particularly interested in the provisioning of connections and VPNs (Virtual Private Networks) within a domain as well as between domains. The architecture is based on the TMN model (TelecommunicationsManagement Network). The TMN model is used to divide the architecture into layers and to define the nomenclature of each layer. The Web Services technology was used to implement the architecture. The implementation was done to validate the architecture and to analyse the usage of Web Services to establish interdomain optical network services. The results presented in this work highlight that by doing the provisioning of services through the services layer facilitate the implementation of the interactions among different domains and offer a new mechanism to support such interactions / Doutorado / Engenharia de Computação / Doutor em Engenharia Elétrica