Virtual Routers as a Service: The Routeflow Approach Leveraging Software-Defined Networks

ABSTRACT The networking equipment market is being transformed by the need for greater openness and flexibility, not only for research purposes but also for in-house innovation by the equipment owners. In contrast to networking gear following the model of computer mainframes, where closed software runs on proprietary hardware, the software-defined networking approach effectively decouples the data from the control plane via an open API (i.e., OpenFlow protocol) that allows the (remote) control of packet forwarding engines. Motivated by this scenario, we propose RouteFlow, a commodity routing architecture that combines the line-rate performance of commercial hardware with the flexibility of open-source routing stacks (remotely) running on general purpose computers. The outcome is a novel point in the design space of commodity routing solutions with far-reaching implications towards virtual routers and IP networks as a service. This paper documents the progress achieved in the design and prototype implementation of our work and outlines our research agenda that calls for a community-driven approach

Toward incremental FIB aggregation with quick selections (FAQS)

Several approaches to mitigating the Forwarding Information Base (FIB) overflow problem were developed and software solutions using FIB aggregation are of particular interest. One of the greatest concerns to deploy these algorithms to real networks is their high running time and heavy computational overhead to handle thousands of FIB updates every second. In this work, we manage to use a single tree traversal to implement faster aggregation and update handling algorithm with much lower memory footprint than other existing work. We utilize 6-year realistic IPv4 and IPv6 routing tables from 2011 to 2016 to evaluate the performance of our algorithm with various metrics. To the best of our knowledge, it is the first time that IPv6 FIB aggregation has been performed. Our new solution is 2.53 and 1.75 times as fast as the-state-of-the-art FIB aggregation algorithm for IPv4 and IPv6 FIBs, respectively, while achieving a near-optimal FIB aggregation ratio

Segment Routing: a Comprehensive Survey of Research Activities, Standardization Efforts and Implementation Results

Fixed and mobile telecom operators, enterprise network operators and cloud providers strive to face the challenging demands coming from the evolution of IP networks (e.g. huge bandwidth requirements, integration of billions of devices and millions of services in the cloud). Proposed in the early 2010s, Segment Routing (SR) architecture helps face these challenging demands, and it is currently being adopted and deployed. SR architecture is based on the concept of source routing and has interesting scalability properties, as it dramatically reduces the amount of state information to be configured in the core nodes to support complex services. SR architecture was first implemented with the MPLS dataplane and then, quite recently, with the IPv6 dataplane (SRv6). IPv6 SR architecture (SRv6) has been extended from the simple steering of packets across nodes to a general network programming approach, making it very suitable for use cases such as Service Function Chaining and Network Function Virtualization. In this paper we present a tutorial and a comprehensive survey on SR technology, analyzing standardization efforts, patents, research activities and implementation results. We start with an introduction on the motivations for Segment Routing and an overview of its evolution and standardization. Then, we provide a tutorial on Segment Routing technology, with a focus on the novel SRv6 solution. We discuss the standardization efforts and the patents providing details on the most important documents and mentioning other ongoing activities. We then thoroughly analyze research activities according to a taxonomy. We have identified 8 main categories during our analysis of the current state of play: Monitoring, Traffic Engineering, Failure Recovery, Centrally Controlled Architectures, Path Encoding, Network Programming, Performance Evaluation and Miscellaneous...Comment: SUBMITTED TO IEEE COMMUNICATIONS SURVEYS & TUTORIAL

Virtualization and Distribution of the BGP Control Plane

L'Internet est organisé sous la forme d'une multitude de réseaux appelés Systèmes Autonomes (AS). Le Border Gateway Protocol (BGP) est le langage commun qui permet à ces domaines administratifs de s'interconnecter. Grâce à BGP, deux utilisateurs situés n'importe où dans le monde peuvent communiquer, car ce protocole est responsable de la propagation des messages de routage entre tous les réseaux voisins. Afin de répondre aux nouvelles exigences, BGP a dû s'améliorer et évoluer à travers des extensions fréquentes et de nouvelles architectures. Dans la version d'origine, il était indispensable que chaque routeur maintienne une session avec tous les autres routeurs du réseau. Cette contrainte a soulevé des problèmes de scalabilité, puisque le maillage complet des sessions BGP internes (iBGP) était devenu difficile à réaliser dans les grands réseaux. Pour couvrir ce besoin de connectivité, les opérateurs de réseaux font appel à la réflection de routes (RR) et aux confédérations. Mais si elles résolvent un problème de scalabilité, ces deux solutions ont soulevé des nouveaux défis car elles sont accompagnées de multiples défauts; la perte de diversité des routes candidates au processus de sélection BGP ou des anomalies comme par exemple des oscillations de routage, des déflections et des boucles en font partie. Les travaux menés dans cette thèse se concentrent sur oBGP, une nouvelle architecture pour redistribuer les routes externes à l'intérieur d'un AS. `A la place des classiques sessions iBGP, un réseau de type overlay est responsable (I) de l'´echange d'informations de routage avec les autres AS, (II) du stockage distribué des routes internes et externes, (III) de l'application de la politique de routage au niveau de l'AS et (IV) du calcul et de la redistribution des meilleures routes vers les destinations de l'Internet pour tous les routeurs clients présents dans l'AS. ABSTRACT : The Internet is organized as a collection of networks called Autonomous Systems (ASes). The Border Gateway Protocol (BGP) is the glue that connects these administrative domains. Communication is thus possible between users worldwide and each network is responsible of sharing reachability information to peers through BGP. Protocol extensions are periodically added because the intended use and design of BGP no longer fit the current demands. Scalability concerns make the required internal BGP (iBGP) full mesh difficult to achieve in today's large networks and therefore network operators resort to confederations or Route Reflectors (RRs) to achieve full connectivity. These two options come with a set of flaws of their own such as route diversity loss, persistent routing oscillations, deflections, forwarding loops etc. In this dissertation we present oBGP, a new architecture for the redistribution of external routes inside an AS. Instead of relying on the usual statically configured set of iBGP sessions, we propose to use an overlay of routing instances that are collectively responsible for (I) the exchange of routes with other ASes, (II) the storage of internal and external routes, (III) the storage of the entire routing policy configuration of the AS and (IV) the computation and redistribution of the best routes towards Internet destinations to each client router in the AS

Datacenter Traffic Control: Understanding Techniques and Trade-offs

Datacenters provide cost-effective and flexible access to scalable compute and storage resources necessary for today's cloud computing needs. A typical datacenter is made up of thousands of servers connected with a large network and usually managed by one operator. To provide quality access to the variety of applications and services hosted on datacenters and maximize performance, it deems necessary to use datacenter networks effectively and efficiently. Datacenter traffic is often a mix of several classes with different priorities and requirements. This includes user-generated interactive traffic, traffic with deadlines, and long-running traffic. To this end, custom transport protocols and traffic management techniques have been developed to improve datacenter network performance. In this tutorial paper, we review the general architecture of datacenter networks, various topologies proposed for them, their traffic properties, general traffic control challenges in datacenters and general traffic control objectives. The purpose of this paper is to bring out the important characteristics of traffic control in datacenters and not to survey all existing solutions (as it is virtually impossible due to massive body of existing research). We hope to provide readers with a wide range of options and factors while considering a variety of traffic control mechanisms. We discuss various characteristics of datacenter traffic control including management schemes, transmission control, traffic shaping, prioritization, load balancing, multipathing, and traffic scheduling. Next, we point to several open challenges as well as new and interesting networking paradigms. At the end of this paper, we briefly review inter-datacenter networks that connect geographically dispersed datacenters which have been receiving increasing attention recently and pose interesting and novel research problems.Comment: Accepted for Publication in IEEE Communications Surveys and Tutorial

New paradigms of legacy network features over SDN Architecture

The Software Define Networking (SDN) paradigm proposes faster implementations, flexibility, and a simplified network management, resulting very attractive to new carrier deployments. Nevertheless, migrating legacy networks to SDN scenarios has been slowed down. Traditional network features, such as high availability, load balancing, and scalability are constrained by the centralized nature of SDN architecture. This study evaluates legacy network features, applied to an SDN network, analyzing the impact of this evolution on the network performance. For the evaluation, a set of virtual scenarios has been implemented, assessing different network parameters, in order to measure the impact on the network performance

Desarrollo de un entorno de evaluación para protocolos de encaminamiento multi-path interdominio

El objetivo de este proyecto es el desarrollo de un entorno de simulación versátil y potente en el que validar protocolos de encaminamiento multi-path interdominio sobre topologías de red. Estas simulaciones son muy importantes, ya que nos permiten determinar cómo se va a comportar un determinado protocolo de encaminamiento, o una variante del mismo sin necesidad de realizar un elevado desembolso económico destinado a la adquisición de hardware en el que realizar pruebas reales, o a invertir una gran cantidad de tiempo tratando de predecir matemáticamente el comportamiento de un modelo generalmente simplificado. En primer lugar se describen las fases iniciales, empezando por la aproximación preliminar a una solución basada en el uso de equipos hardware reales, y seguidamente por una solución basada en máquinas virtuales. También se justifica por qué ambas alternativas fueron descartadas para dar lugar a una tercera solución basada en utilizar simuladores de red. Se detallan los estudios comparativos realizados entre distintas aplicaciones existentes y se justifica por qué ampliar el simulador C-BGP en vez de las otras alternativas. A partir de aquí se describen los cambios necesarios en la estructura del simulador para dar soporte multi-path, y la validación del mismo mediante la implementación de dos variantes de BGP multi-path propuestas en el proyecto Trilogy: LP-BGP y MpASS. Debido a diversas dificultades encontradas a lo largo del desarrollo del simulador, se plantea la creación de una herramienta, , esta comienza siendo una aplicación de consola para generar scripts, convertir entre formatos de ficheros de topologías y proporcionar información sobre las mismas, pero que acaba siendo una potente y versátil aplicación multiplataforma con interfaz gráfica de usuario que cumple los estándares de accesibilidad y que sigue una serie de patrones de diseño que hacen que su código fuente sea reutilizable, muy escalable y fácilmente mantenible. Seguidamente se muestran los resultados de aplicar el simulador y las dos variantes multi-path (LP-BGP y MpASS) a dos pequeñas topologías de prueba y a una tercera topología con un tamaño de una magnitud similar a la de Internet. Aquí se puede comprobar cómo desde un solo computador pueden obtenerse en un tiempo muy razonable unos resultados para los que en otro caso necesitaríamos una gran cantidad de hardware. Tras la validación de resultados se detallan los costes asociados a los distintos medios empleados para la realización del proyecto, y se adjunta un diagrama de Gantt en el que se muestra la distribución de tiempo en las distintas fases del proyecto. Finalmente se completa la memoria con el glosario de términos, la bibliografía y los anexos. En el primero se explican los comandos añadidos al simulador C-BGP junto con ejemplos de uso y en el segundo se incluye el manual de usuario de la herramienta anteriormente mencionada. _________________________________________________________________________________________The current project details the steps taken to get a powerful and versatile environment, to simulate multi-path routing protocols on network topologies. These simulations are very important because they allow us to determine how it will behave a particular routing protocol or a variation thereof without making a major financial outlay for the purchase of hardware on which make actual testing, nor investing a lot of time trying to make a mathematical approach that predicts such behavior. First, initial stages are described, beginning with the first approach to a solution based on the use of real hardware devices, followed by a solution based on virtual machines. Also why these solutions were dropped to make way for a solution based on using network simulators. A detailed comparative study between different existing applications is provided next, and is justified by what extend the C-BGP simulator instead of the other existing alternatives. From here we describe the necessary changes in the structure of the simulator to allow multi-path support, and validation of the same by implementing two variants of BGP multi-path proposed in Trilogy project: LP-BGP and MpASS. Due to various difficulties encountered during the development of the simulator, we propose the creation of a tool, , which starts as a console application to generate scripts, convert between topology file formats and provide information about them, but it becomes a powerful and versatile application with graphical user interface that meets accessibility standards and follows a series of design patterns that make its source code reusable, highly scalable and easily maintainable. In the next part, results of applying the simulator with the two variants of BGP multi-path (LP-BGP and MpASS) are shown. It was tested in a couple of small test topologies and in a third topology with a size of a similar magnitude to the Internet. Reading these results you can realize that with a single computer and in a reasonable time is possible to get some results for those who otherwise would have been necessary a large amount of hardware. After validating the results, next you can find the detailed cost for the items used in the budget for the project. A Gantt diagram is also included. It shows the distribution of time in the different phases of the project. Finally, the document gets completed with a glossary of terms, the bibliography and the annexes. In the first one, the new commands added to C-BGP are explained with examples of use. The second one contains user manual.Ingeniería en Informátic