Future Internet Routing Design for Massive Failures and Attacks

Given the high complexity and increasing traffic load of the Internet, geo-correlated challenges caused by large-scale disasters or malicious attacks pose a significant threat to dependable network communications. To understand its characteristics, we propose a critical-region identification mechanism and incorporate its result into a new graph resilience metric, compensated Total Geographical Graph Diversity. Our metric is capable of characterizing and differentiating resiliency levels for different physical topologies. We further analyze the mechanisms attackers could exploit to maximize the damage and demonstrate the effectiveness of a network restoration plan. Based on the geodiversity in topologies, we present the path geodiverse problem and two heuristics to solve it more efficiently compared to the optimal algorithm. We propose the flow geodiverse problem and two optimization formulations to study the tradeoff among cost, end-to-end delay, and path skew with multipath forwarding. We further integrate the solution to above models into our cross-layer resilient protocol stack, ResTP–GeoDivRP. Our protocol stack is prototyped and implemented in the network simulator ns-3 and emulated in our KanREN testbed. By providing multiple GeoPaths, our protocol stack provides better path restoration performance than Multipath TCP

Métodos de melhoria da disponibilidade e da resiliência a desastres em redes de telecomunicações

In current societies, telecommunication networks are one of its essential components, in which different services depend on. Critical service requires these networks to provide high levels of availability between their nodes and high levels of resilient to large-scale natural disasters, either by avoiding them or quickly recover from them. Different techniques can be used to reach these goals. In this dissertation, it is considered the use of geodiversity routing to reduce the impact of large-scale disasters, with the downside of utilizing longer paths which, in turn, reduces the resulting end-to-end availability. This downside can be corrected if the availability of some network elements are upgraded so that the availability required by critical services is met, while maintaining the geodiversity required to prevent the impact of disasters. In this dissertation, different upgrade strategies are implemented to efficiently identify the network elements required to be upgraded, so that the network can provide critical services with high availability and high resilience to natural disasters.As redes de telecomunicações são um dos componentes essenciais na atual sociedade, no qual vários serviços dependem da sua funcionalidade para operarem eficientemente. O suporte de serviços críticos exige que as redes ofereçam altos níveis de disponibilidade entre os seus nós e sejam altamente resilientes a desastres de larga escala, tais como os provocados por fenómenos naturais (tremores de terra, tsunamis, etc.). Algumas técnicas podem ser implementadas para atingir estes objetivos. Nesta dissertação, considera-se o uso de encaminhamento com geodiversidade para reduzir o impacto de desastres de larga escala, com a desvantagem de exigir percursos de encaminhamento mais longos, reduzindo a disponibilidade resultante entre os nós origem-destino do encaminhamento. Assim, para obter simultaneamente alta disponibilidade e alta resiliência a desastres, é necessário melhorar a disponibilidade em alguns elementos da rede. Nesta dissertação são introduzidas diferentes estratégias para identificar eficazmente os elementos da rede que precisam de ser melhorados em termos de disponibilidade, para que a rede suporte os requisitos de disponibilidade e resiliência a desastres requeridos por serviços críticos.Mestrado em Engenharia Informátic

The minimum cost D-geodiverse anycast routing with optimal selection of anycast nodes

Consider a geographical network with associated link costs. In anycast routing, network nodes are partitioned into two sets - the source nodes and the anycast (destination) nodes - and the traffic of each source node is routed towards the anycast node providing the minimum routing cost path. By considering a given geographical distance parameter D, we define an anycast routing solution as D-geodiverse when for each source node there are two routing paths, each one towards a different anycast node, such that the geographical distance between the two paths is at least D. Such a solution has the property that any disaster with a coverage diameter below D affecting one routing path (but without involving neither the source node nor its entire set of outgoing links) cannot affect the other path, enhancing in this way the network robustness to natural disasters. The selection of the anycast nodes has an impact both on the feasibility and cost of a D- geodiverse anycast routing solution. Therefore, for a desired number of anycast nodes R, we define the minimum cost D- geodiverse anycast problem (MCD-GAP) aiming to identify a set of R anycast nodes that obtain a minimum cost routing solution. The problem is defined based on integer linear programming and is extended to consider the existence of vulnerability regions in the network, i.e., by imposing the geographical distance D only between network elements belonging to the same region. We present computational results showing the tradeoff between D and R in the optimal solutions obtained with and without vulnerability regions.This paper is based upon work from COST Action CA15127 ("Resilient communication services protecting end user applications from disaster-based failures ‒ RECODIS") supported by COST Association. The work was financially supported by FCT, Portugal, under the projects CENTRO- 01-0145-FEDER-029312 and UID/EEA/50008/2013 and through the postdoc grant SFRH/BPD/ 111503/2015.publishe

ResTP: A Configurable and Adaptable Multipath Transport Protocol for Future Internet Resilience

Motivated by the shortcomings of common transport protocols, e.g., TCP, UDP, and MPTCP, in modern networking and the belief that a general-purpose transport-layer protocol, which can operate efficiently over diverse network environments while being able to provide desired services for various application types, we design a new transport protocol, ResTP. The rapid advancement of networking technology and use paradigms is continually supporting new applications. The configurable and adaptable multipath-capable ResTP is not only distinct from the standard protocols by its flexibility in satisfying the requirements of different traffic classes considering the characteristics of the underlying networks, but by its emphasis on providing resilience. Resilience is an essential property that is unfortunately missing in the current Internet. In this dissertation, we present the design of ResTP, including the services that it supports and the set of algorithms that implement each service. We also discuss our modular implementation of ResTP in the open-source network simulator ns-3. Finally, the protocol is simulated under various network scenarios, and the results are analyzed in comparison with conventional protocols such as TCP, UDP, and MPTCP to demonstrate that ResTP is a promising new transport-layer protocol providing resilience in the Future Internet (FI)

Network Resilience Architecture and Analysis for Smart Homes

The Internet of Things (IoT) is evolving rapidly to every aspect of human life including, healthcare, homes, cities, and driverless vehicles that makes humans more dependent on the Internet and related infrastructure. While many researchers have studied the structure of the Internet that is resilient as a whole, new studies are required to investigate the resilience of the edge networks in which people and “things” connect to the Internet. Since the range of service requirements varies at the edge of the network, a wide variety of technologies with different topologies are involved. Though the heterogeneity of the technologies at the edge networks can improve the robustness through the diversity of mechanisms, other issues such as connectivity among the utilized technologies and cascade of failures would not have the same effect as a simple network. Therefore, regardless of the size of networks at the edge, the structure of these networks is complicated and requires appropriate study. In this dissertation, we propose an abstract model for smart homes, as part of one of the fast-growing networks at the edge, to illustrate the heterogeneity and complexity of the network structure. As the next step, we make two instances of the abstract smart home model and perform a graph-theoretic analysis to recognize the fundamental behavior of the network to improve its robustness. During the process, we introduce a formal multilayer graph model to highlight the structures, topologies, and connectivity of various technologies at the edge networks and their connections to the Internet core. Furthermore, we propose another graph model, technology interdependence graph, to represent the connectivity of technologies. This representation shows the degree of connectivity among technologies and illustrates which technologies are more vulnerable to link and node failures. Moreover, the dominant topologies at the edge change the node and link vulnerability, which can be used to apply worst-case scenario attacks. Restructuring of the network by adding new links associated with various protocols to maximize the robustness of a given network can have distinctive outcomes for different robustness metrics. However, typical centrality metrics usually fail to identify important nodes in multi-technology networks such as smart homes. We propose four new centrality metrics to improve the process of identifying important nodes in multi-technology networks and recognize vulnerable nodes. We perform the process of improvement through modifying topology, adding extra nodes, and links when necessary. The improvement process would be verified by calculation of the proper graph metrics and introducing new metrics when it is appropriate. Finally, we study over 1000 different smart home topologies to examine the resilience of the networks with typical and the proposed centrality metrics

Análisis de supervivencia en infraestructuras críticas

La dependencia del ser humano en el correcto funcionamiento de las redes de servicios ha ido incrementando con el tiempo. A la vez, también ha incrementado el riesgo ante fallos en las redes, principalmente debido al aumento de la complejidad y a las dependiencias presentes en las mismas. A raíz de este hecho surge la necesidad de aumentar la resiliencia de las redes, donde los costes de los incidentes se propagan de manera drástica a lo largo de la red, afectando a numerosos clientes e impactando tanto en los resultados como en la imagen de la empresa. Combinando la fiabilidad con el Input-Outup Inoperability Model (IIM) y con una técnica novedosa como es el Path Diversity, se logra un modelo aplicable a todo tipo de redes y con unos resultados prometedores, confirmándolo como una valiosa herramienta de cara a la toma de decisiones de una organización. El modelo nos permite de manera rápida y eficiente determinar a aquellos puntos de la red con mayor riesgo, pudiendo así realizar un mantenimiento más eficiente sobre dichos puntos.Universidad de Sevilla. Máster Universitario en Ingeniería Industria