Recently, there has been substantial progress in the formal understanding of how caching resources should be allocated when multiple caches each deploy the common LRU policy. Nonetheless, the role played by caching policies beyond LRU in a networked setting where content may be replicated across multiple caches and where channels are unreliable is still poorly understood. In this paper, we investigate this issue by first analyzing the cache miss rate in a system with two caches of unit size each, for the LRU, and the LFU caching policies, and their combination. Our analytical results show that joint use of the two policies outperforms LRU, while LFU outperforms all these policies whenever resource pooling is not optimal. We provide empirical results with larger caches to show that simple alternative policies, such as LFU, provide superior performance compared to LRU even if the space allocation is not fine tuned. We envision that fine tuning the cache space used by such policies may lead to promising additional gains.

O maior desafio no desenvolvimento de emuladores de redes SDN é torná-los mais realistas, versáteis e abertos. Além disso, eles também devem oferecer aplicações reais em seus experimentos, porém, devido à complexidade de integrá-las ao emulador, estas características nem sempre são desenvolvidas. Para oferecer uma solução mais diversificada e flexível que as atuais (ex. Mininet ou vEmulab), este artigo apresenta o vSDNEmul, um emulador de redes SDN onde os nós são baseados em contêineres Docker.

Para construção de redes virtuais definidas por softwares (vSDN), também conhecidas como slices da infraestrutura física, é necessário a utilização de soluções de hipervisores SDN. No entanto, essas soluções vêm apresentando grandes limitações de escalabilidade e desempenho, por causa de sua arquitetura baseada em proxy de serviços. Este artigo apresenta uma proposta de orquestração diferente do modelo atual provendo redes virtuais definidas por softwares através da alocação de instancias de switches virtuais sob demanda diretamente em dispositivos de comutação de baixo custo.

Software Defined Networks separates the control and forwarding planes, facilitating and flexibilizing the management of networking. However, the interaction between these planes introduces different vulnerabilities to the network, raising new resilience concerns. To assist the planning phase of a Software Defined Network deployment, this paper proposes the application of topological augmentation algorithms to increase the resilience of topologies as indicated by a resilience factor, through optimizations on both control and forwarding planes. In parallel, a brute force controller placement algorithm is applied, for performance comparisons. Tests results demonstrate that the improvement on the test topologies’ resilience characteristics obtained by the joint optimization of both planes surpasses even the most optimal controller placement.

The Novel Enablers for Cloud Slicing (NECOS) project addresses the limitations of current cloud computing infrastructures to respond to the demand for new services, as presented in two use-cases, that will drive the whole execution of the project. The first use-case is focused on Telco service provider and is oriented towards the adoption of cloud computing in their large networks. The second use-case is targeting the use of edge clouds to support devices with low computation and storage capacity. The envisaged solution is based on a new concept, the Lightweight Slice Defined Cloud (LSDC), as an approach that extends the virtualization to all the resources in the involved networks and data centers and provides uniform management with a high-level of orchestration. In this position paper, we discuss the motivation, objectives, architecture, research challenges (and how to overcome them) and initial efforts for the NECOS project.

Um dos maiores desafios para emuladores de redes SDN são faze-los cada vez mais realistas, versáteis e abertos. Além disso, eles também devem oferecer aplicações reais em seus experimentos, porém, devido a complexidade de integra-los ao emulador estas características não são desenvolvidas. Portanto, para oferecer uma solução mais diversificada que as atuais (ex. Mininet ou vEmulab). Este artigo propõe o vSDNEmul, uma alternativa de emulador de redes SDN onde os nós são baseados em contêineres. Além disso, o artigo também descreve a sua arquitetura e API.

Os switches whitebox vêm sendo uma alternativa vantajosa para o plano de dados SDN. Eles permitem tanto a redução nas despesas como também a ampliação dos níveis de heterogeneidade de fabricantes na infraestrutura de rede. Recentes ferramentas possibilitaram que os whiteboxes baseados em software-switches pudessem ampliar seus desempenhos apenas com otimizações feitas via softwares abertos em hardwares genéricos. A partir disso, propõe-se o vSDNBox, uma alternativa de whitebox software-switched para redes definidas por software, capaz de reduzir ainda mais os custos e ampliar o desempenho através de seu gerenciamento e otimizações feitas via software no espaço do usuário. Os resultados obtidos comprovam que a proposta consegue ter um desempenho igual ou aproximado de um whitebox hardwareswitched através de avaliações de vazão e latência.

Software Defined Networks is a paradigm that flexibilizes the management of networking, separating the control and forwarding planes. This separation introduces new concerns towards the resilience of the network, which now presents different vulnerabilities related to the interaction between these planes. A resilience factor for Software Defined Networks is proposed, using multiple metrics to analyze intrinsic features of its architecture, serving as an indication for its resilience. Beyond that, topological augmentation algorithms are employed to increase the resilience of test topologies, as indicated by the proposed factor. Tests results demonstrate an improvement of the topologies’ resilience characteristics.

Redes Definidas por Software é um paradigma que exibilizaa gerência de redes de computadores ao separar os planos de controle e de dados. Essa separação introduz novas preocupações quanto a resiliência da rede, que passa a apresentar diferentes vulnerabilidades relacionadas a interação entre os planos. É proposto um fator de resiliência para Redes Definidas por Software, utilizando múltiplas métricas para analisar características intrínsecas da arquitetura, servindo como indicativo de resiliência da rede. Além disso, algoritmos de aprimoramento topológico são empregados para aperfeiçoar a resiliência das topologias utilizadas. Os resultados de monstram melhoria nas características de resiliência.

As Redes virtuais Definidas por Software (vSDNs) são a junção de SDN e Virtualização. Neste contexto, o hipervisor de rede é responsável pela gestão da rede física, enquanto a rede SDN não virtualizada mantém esta função no controlador. Este artigo apresenta o Search Path, um buscador de caminhos baseado em grafos que evita traduções desnecessárias entre o hipervisor de rede e os controladores no contexto de vSDNs. A fatia encaminhada pelo hipervisor de rede é recebida pelo Search Path em forma de grafos, facilitando o desenvolvimento de lógicas de encaminhamento específicas para cada rede, através da manipulação de grafos. Os testes realizados demonstram que o Search Path possui resultados melhores quando comparado com hipervisor de rede e controlador tradicionais.

Software-Defined Networking (SDN) has turned the Data Center Network (DCN) environment into a more flexible one by decoupling control plane from data plane, allowing an innovative and easily extensible network management solutions. Nowadays, OpenFlow is the most successful protocol for SDN. However, SDN based on OpenFlow protocol presents performance issues on forwarding table increasing and packet match cost. Our proposal named Tag-and-Forward (TF) is a data plane that reduces the number of flow table required in the Fat-Tree software-defined DCNs to optimize forwarding. The results noticebly outperformed RTT and packet transmission rate when compared to usual OpenFlow data plane.

Software-Defined Networking (SDN) has been one of the most successfull networking model over the past few years. The model decouples the network control and forwarding functions enabling the underlying infrastructure complexity to be programmed by applications. Although control plane is the cern for all the benefits, it is also the most crucial drawback of the SDN model to keep up working. Therefore, this paper presents a performance analysis on mainstream open-source SDN controllers. The results show that a well-perfomed control plane not only depends on controller throughput and response time, but also relies on topology discovery time. Our results show that Beacon controller has the highest performance on controller troughput because it uses multicore feature better than others. However, there is a few difference on topology building delay when compared to ONOS, Floodlight and OpenDaylight, which are also Java-based controllers. The worst one is Ryu for building network topology.

One way to provide more flexibility for computer networks is through software defined networks (SDN). This paradigm supports network applications, whose behavior is defined by the controllers. However, management applications SDN is a solution under explored, such applications are scattered in various repositories codes on-line, or are still embedded in the factory switches. This article proposes a model of organization and distribution of applications, called SDNrepo, may specify and model all the way that applications must do to reach the end user, in this case the controllers.

This paper describes the experience of RNP, the Brazilian research and education network, in creating a large scale research facility for experimentation on Future Internet as a member of the FIBRE (Future Internet testbeds experimentation between BRazil and Europe) project. Its main goal is to create common space between Brazil and EU for Future Internet experimental research into network infrastructure and distributed applications, by building and operating a federated EU-Brazil Future Internet experimental facility. The FIBRE testbed is currently composed by a federation of 13 local testbeds (a.k.a. experimental islands), located in different R&E organizations. The FIBRE infrastructure combines heterogeneous physical resources and different technologies, including OpenFlow, wireless and optical communications. We also present the architecture of FIBRE, which allows users to access the testbed through an integrated interface for either experimental or control planes, and provides a common access to the different underlying Control and Monitoring Frameworks (CMFs) for Future Internet experimentation

The Future Internet approach requires new solutions to support novel usage scenarios driven by the technological evolution and the new service demands. However, this paradigm shift requires deeper changes in the existing systems, which makes Internet providers reluctant in deploying the full transformation required for the Future Internet. The Entity Title Architecture (ETArch) is a holistic clean-slate Future Internet system embedding new services for these scenarios leveraging the Software Defined Networking (SDN) concept materialized by the OpenFlow. However, legacy ETArch deploys a fully per-flow approach to provision the same transport model for all sessions (equivalent to the Internet best-effort), while suffering with performance drawbacks and lacking Quality of Service (QoS) control. To that, we evolved ETArch with SMART (Support of Mobile Sessions with High Transport Network Resource Demand) QoS control approach, which coordinates admission control and dynamic control of super-dimensioned resources to accommodate multimedia sessions with QoS-guaranteed over time, while keeping scalability/performance and users with full Quality of Experience (QoE). The SMART-enabled ETArch system evaluation was carried out using a real Testbed of the OFELIA Brazilian Island, confirming its benefits in both data and control planes over the legacy ETArch.

Software Defined Networking (SDN) has emerged as a new paradigm that highly increase the network management flexibility through simple but powerful abstractions. The key idea is decoupling the control plane, which makes the forward decisions, from the data plane, which effectively makes the forward. However, the OpenFlow, the main SDN enabler, is designed mainly by wired networks characteristics. As consequence, Wireless Mesh Networks (WMNs) is not suitable for operating as control plane and many wireless networks features are neglected in the OpenFlow, e.g.: power control and network ID. In addition, there are few effort research to extend SDN to wireless networks and these existing works focus on very specific issues of this integration. In this paper, we propose an architecture to extent the OpenFlow functionalities in order to proper deal with wireless networks, including an approach for transporting the control plane over wireless multihop networks. The extensions include new rules, actions, and commands, which bring the network management flexibility to the wireless context. We validated our proposal by implementing and testing some extensions in a small real world testbed. As a proof of concept, we illustrate the OpenFlow capability of isolation between research and production traffics in a wireless backhaul.

. On the context of OpenFlow networks, the FlowVisor has emerged as a tool to enable the network virtualization, creating an environment for running multiple concurrent and independent experiments. However, this solution still has some limitations, such as the definition of mechanisms to allocate resources to different virtual networks. Although newer versions of the tool allow the queue assignment network slice, to provide resource control among them, device configurations are on the dependency of external tools. Therefore, this article aims to propose a solution to extend the FlowVisor functionality, creating a structure to allow traffic control configuration parameters in the network device, to ensure resource isolation and interference mitigation between the different virtual networks.

Packet scheduling is essential to properly support applications on Software-Defined Networking (SDN) model. However, on OpenFlow/SDN, QoS is only performed with bandwidth guarantees and by a well-known FIFO scheduling. Facing this limitation, this paper presents the QoSFlow proposal, which controls multiple packet schedulers of Linux kernel and improve the flexibility of QoS control. The paper assesses QoSFlow performance, by analysing response time of packet scheduler operations running on datapath level, maximum bandwidth capacity, hardware resource utilization rate, bandwidth isolation and QoE. Our outcomes show an increase more than 48% on PSNR value of QoE by using SFQ scheduling.

The increase in complexity of computer networks and their services have boosted the development of standardizations, models, and solutions for network management over the years. Lately, the Distributed Management Task Force (DMTF) defined the Common Information Model (CIM) for describing computational entities and businesses on the Internet. This paper proposes an extension of the CIM for Software-Defined Networking (SDN) by adding new elements (Controllers, Apps, Slices and others) to improve the system management performance. Furthermore, we define a metamodel to help the process of creating and understanding the proposed model. The proposal was validated by creating a script that generates the FlowVisor configuration file using the network model as input and using Object Constraint Language (OCL) to find inconsistencies in the network.

Currently, there is a philosophical problem that arises between the real need for current support to OpenFlow and legacy network infrastructure. Among them, the legacy networking has not been compatible with OpenFlow network, and for that, it needs to be replaced or a few cases upgraded, as a consequence there are additional spending with new equipment OpenFlow-based. This paper introduces a proposal of hybrid SDN solution based on OpenFlow protocol and called of LegacyFlow, which is able to control Legacy equipment (non-OpenFlow) through OpenFlow protocol 1.0. Results show that it is possible used the LegacyFlow together with OpenFlow switches keeping a good performance time with OpenFlow application.

The OpenFlow technology enables the creation of a programmable layer over the control-plane of a network, in this way dictating the data-plane forwarding behaviour through the use of applications plugged to a network controller. Dynamic Circuit Network is an architecture that permits the scheduling of network resources on virtual circuits, such as bandwidth, over multiple domains with heterogeneous technologies. Recently, researches were conducted in order to integrate both technologies so that dynamic circuits can be dynamically provisioned over OpenFlow domains. The objective of this work is to propose an architecture that enables such provision, maintaining the QoS requisites of a DCN architecture.

The Future Internet will arise from the convergence of new network concepts and combine technologies, services, media and content. It will offer flexibility and diversity with scalable content and services that are accessible through a wide range of interfaces and devices. However, the biggest challenge now is how to enable and test the proposed approaches so that they can be validated without sacrificing the current production infrastructure. The OpenFlow protocol allows production networking environments such as campus networks, metropolitan networks or R&D networks, to be used as experimental infrastructure hosting, future Internet architectures, software and protocols, in parallel with the production traffic. During rollout, there is a practical problem that arises with Legacy networks that do not support OpenFlow and need to be replaced/upgraded or refined by means of costly network re-engineering. This paper proposes a new OpenFlow architecture with new components, capable of managing Legacynon-OpenFlow elements by offering a new solution that facilitates the management of Legacy technologies and allows them to be employed in FI experimentation environment and increase the number of experiment with the Legacy Network Environment using OpenFlow control.

Nos últimos anos houve expressivo esforço em prol de soluções de mobilidade para redes sem fio tradicionais, tais como redes de celulares e IEEE 802.11. Outro tipo de rede sem fio que vem se destacando mais recentemente são as redes de múltiplos saltos. Porém a questão da mobilidade neste tipo de rede não é uma simples extensão das redes sem fio tradicionais. Assim, são necessárias soluções específicas de mobilidade que atendam os requisitos dessas novas redes. Visando este objetivo, o presente trabalho propõe uma adaptação ao DHCP, voltado para redes sem fio de múltiplos saltos. A proposta agrega inteligência ao agente DHCP relay, tornando-o capaz de acelerar o processo de configuração de endereço IP aos clientes móveis durante o handoff.

Os tradicionais sistemas de prevenção de intrusão (Intrusion Prevention Systems–IPS) possuem limitações em sua atuação. Quando operam no modo ativo, não possuem uma ampla cobertura na rede, e quando capturam tráfego espelhado, só bloqueiam o tráfego malicioso se atuarem em conjunto com equipamentos de rede do mesmo fabricante ou solução. Neste contexto, propomos neste artigo o IPSFlow, um framework de IPS para Redes Definidas por Software (Software Defined Networks-SDN) que, através do protocolo Openflow, possibilita a criação de um IPS com ampla cobertura na rede, permitindo a captura seletiva e o bloqueio automatizado de tráfego malicioso o mais próximo de sua origem, através da combinação dos resultados de diferentes técnicas de análise de tráfego.