Artigos de Conferência, Publicação

Busca de caminhos como serviço em vSDNs

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.

Artigos de Conferência, Publicação

Tag-and-Forward: A source-routing enabled data plane for OpenFlow Fat-Tree Networks

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.

Artigos de Conferência, Publicação

A Two-Tier Adaptive Data Aggregation Approach for M2M Group-Communication

Network lifetime is the time interval in which the nodes are operational. Considering that machine-to-machine (M2M) devices have limited energy resources, an important challenge in M2M communications is to prolong the network lifetime. The constrained application protocol (CoAP) supports multi-target monitoring applications in M2M communications, allowing the creation and maintenance of groups, as well as their periodic communication. It is essential to aggregate the CoAP group-communication over the paths to increase the network lifetime of low-power M2M devices, since data aggregation reduces the use of energy-consuming hardware (e.g., central processing unit and wireless interface). However, the current data aggregation solutions do not specify how to support data aggregation with multiple CoAP-based groups in multi-target monitoring applications. In this paper, the proposed approach, called two-tier aggregation for multi-target applications (TTAMAs), aggregates the data originated from nodes belonging to either the same or different CoAP groups. Furthermore, TTAMA is an adaptive solution because it performs the data aggregation in accordance with the CoAP configurations, such as communication periodicity and data aggregation functions. We compare TTAMA with current data aggregation approaches that use minimum spanning tree and shortest path tree. The results show that TTAMA outperforms the related works in terms of network lifetime and energy consumption.

Artigos de Conferência, Publicação

Cache-Aware Interest Routing: Impact Analysis on Cache Decision Strategies in Content-Centric Networking

Information-Centric Networking (ICN) is one of the most promising model for dealing with the cern of the current Internet scenario, that is content. In this model, either routers or user devices in the network are capable of storing content in cache, where a client device pull a content by expressing an interest of the desired content name. One of the most sucessfull implementation of ICN is Content-Centric Networking (CCN) proposed by PARC. In CCN, the forwarding strategy pushes interest packets torwards a content server through a route determined by the Shortest-Path Route (SPR) strategy. However, SPR cannot fully exploit the network caching benefits, because the caching process only happens within the path without considering cache saturation level. Therefore, we propose Least Cache Routing (LCR) cache-aware strategy. Besides being based on SPR, LCR is constantly looking for the least saturated paths. The results shows that, a slight improvement on forwarding strategy is capable of improving LCE and LCD cache decision policies. Our results shows 150% and 53% performance gain on cache hit probability when LCR is jointly running with, respectively, LCE and LCD on Torus network.

Artigos de Conferência, Publicação

On the Benchmarking Mainstream Open Software-Defined Networking Controllers

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.

Periódicos, Publicação

Uma estratégia para o serviço de cálculo de caminhos em redes definidas por software

O paradigma de redes definidas por software (SDN) está sendo investigado como a solução mais promissora para o atual engessamento da internet, uma vez que propõe a dissociação entre o plano de dados e o plano de controle, proporcionando maior programabilidade às redes de computadores. No entanto, ainda há lacunas em serviços disponíveis nessa arquitetura, dentre as quais se observa o serviço de cálculos de caminhos, que não está evoluindo consideravelmente entre os controladores. Por exemplo, a reserva de recursos, a partir dos requisitos necessários de cada aplicação, permanece como um desafio a ser vencido. Este artigo apresenta uma estratégia de cálculo de caminhos para redes SDN. O objetivo é oferecer um serviço mais flexível no estabelecimento de fluxos OpenFlow, além de possibilitar restrições determinísticas de qualidade vindas das aplicações. A proposta contribui também com uma arquitetura que pode ser aplicada a controladores SDN, um algoritmo de busca, baseado em uma métrica de qualidade de serviço (QoS), e uma análise de desempenho, mostrando que o algoritmo é capaz de minimizar o tempo de busca, processamento e consumo de memória pelo controlador na rede SDN.

Periódicos, Publicação

NVP: A Network Virtualization Proxy for Software Defined Networking

The combination of Network Function Virtualization (NFV) and Software Defined Networking (SDN) can improve the control and utilization of network resources. However, this issue still requires proper solutions to virtualize large-scale networks, which would allow the use of SDN and Virtualization in real environments.Thus, this paper proposes a virtualization architecture for SDN that relies on a proxy-based approach. The NVP (Network Virtualization Proxy) is a virtualization proxy that intercepts messages exchanged between controllers and switches SDN enabling network virtualization. An implementation of the proposal was developed as a proof of concept and load testing was performed showing that the solution can provide network virtualization in a scalable manner, using less than 2.5 MB of memory to manage 100 switches performing simultaneous requests, whereas FlowVisor requires more than 200 MB.

Artigos de Conferência, Publicação

A MultiCriteria Caching Decision for information centric networks

Information Centric Networks (ICN) has been a new network paradigm and it has attracted a lot of attention recently. In this new model, contents are retrieved by their name, not by IP address, shifting from host-to-host to a host-to-content approach. In networking-caching plays a very important role in ICN, which enables routers to cache content in the path between a user and the permanent server, for instance. These intermediate nodes use a caching scheme to decide whether to store a content or not. However, most of the current caching schemes are only-one-criterion based and, given the dynamics of the network, this only one criterion may not be suitable, resulting in both low network hit ratio and performance. Therefore, we designed a MultiCriteria Caching Decision scheme for ICN, which not only considers one criterion for caching decision, but it aggregates three of them to better distribute content over the network and provide user’s requests. Our results got a much higher cache hit ratio than the other evaluated schemes and a reasonable download time.

Artigos de Conferência, Publicação

Data aggregation for machine-to-machine communication with energy harvesting

Machine-to-Machine (M2M) communications have emerged as a new concept for the next generation of sensing and actuating systems. With the recent emergence of energy harvesting technologies, the current communication solutions have addressed the problem of controlling the data communication to regulate efficiently the energy consumption, aiming to avoid under and overuse of energy. However, these solutions do not consider data aggregation as means of controlling the network traffic. To fill this gap, this paper proposes the Data Aggregation for energy harVesting NETworks (DAV-NET), which regulates the energy consumption in accordance with the residual energy stored in the batteries, exploiting the data aggregation capabilities to control the network traffic. The performed simulations show that the proposed solution is able to regulate the energy consumption in case of abundant or scarce energy, controlling the aggregation level in a distributed fashion.

Artigos de Conferência, Publicação

Controlling Data Aggregation and communication periodicity in Energy Harvesting networks

Machine-to-Machine (M2M) communication is an emerging paradigm for the next generation of sensing and actuating systems. Energy harvesting technologies applied in sensor and actuator devices must be considered by the communication solutions in order to achieve energy-efficient M2M communication. This paper addresses the problem of regulating the energy consumption in accordance with the harvested energy. Thus, it proposes Data Aggregation and communication Periodicity control for Energy Harvesting (DAPEH), a solution that controls the network energy consumption adjusting the Data Aggregation level and the periodicity of the communication. Data Aggregation allows DAPEH to control the amount of traffic sent over the network, while the communication periodicity enables the regulation of data production. The evaluation of the proposed solution uses real measurements of solar harvested energy and shows how the network can increase or decrease the energy consumption to avoid under and overuse of energy.

Artigos de Conferência, Publicação

How to automatically collect oriented object metrics: A study based on systematic review

Aim: Getting information to automatically collect object oriented metrics (OO metrics) in order to assist the comprehension and assessment of software products. Method: It was developed a study based on a systematic review and 37 primary studies were selected from 577 papers retrieved in 3 databases. Result: 177 metrics that can be automatically collected were cataloged. Besides, 27 from such total were the most referenced. The cataloged metrics were classified according to the quality characteristics which were related; 18 collection tools have been identified. This way, it was concluded that there is a set of common procedures for collecting OO metrics and the Java and C++ are the languages with the largest number of tools on which is possible to extract metrics.

Artigos de Conferência, Publicação

Building an infrastructure for experimentation between Brazil and Europe to enhance research collaboration in future Internet

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.

Artigos de Conferência, Publicação

Fibre-an international testbed for future internet experimentation

This paper describes the FIBRE testbed, a large-scale research facility for experimentation on Future Internet. The current testbed is a federation of 13 local testbeds (aka experimental islands), located in different R&E organizations. The FIBRE infrastructure combines heterogeneous physical resources and different technologies, including OpenFlow, wireless and optical communications. This paper discusses the architecture of FIBRE, which includes different Control Management Frameworks, and describes how the testbed can be used in research and education to experiment with networking and distributed systems.

Artigos de Conferência, Publicação

Data Aggregation for group communication in Machine-to-Machine environments

The energy resources of Machine-to-Machine (M2M) devices need to last as much as possible. Data aggregation is a suitable solution to prolong the network lifetime, since it allows the devices to reduce the amount of data traffic. In M2M systems, the M2M platform and the Constrained Application Protocol (CoAP) enable multiple entities to send concurrent data-requests to the same capillary network. For example, in a Smart Metering scenario, there are devices measuring the electricity consumption of an entire building. The supplier company requests all devices to send the data updates every 1800 seconds (i.e., 30 minutes). On the other hand, a resident requests his/her devices to communicate every 600 seconds (i.e., 10 minutes). These concurrent data-requests create heterogeneous groups over the same capillary network, since each group might be able to execute different in-network functions and to have a unique temporal-frequency of communication. However, the traditional data aggregation solutions designed for periodic monitoring assume the execution of a single static data-request during all network lifetime. This makes the traditional data aggregation solutions not suitable for M2M environments. To fill this gap, this paper presents Data Aggregation for Multiple Groups (DAMiG), which is designed to provide Data Aggregation for heterogeneous and concurrent sets of CoAP data-requests. DAMiG explores the group communication periodicity to perform internal and external-group traffic aggregation. To achieve that, DAMiG computes a suitable aggregation structure and applies statistical and merger aggregation functions along the path. DAMiG is able to reduce the energy consumption in scenarios with single or several concurrent CoAP data-requests. Moreover, the selection of internal and external-group paths takes into account the residual energy of the nodes, avoiding the paths with low residual energy.

Artigos de Conferência, Publicação

Efficient and secure M2M communications for smart metering

Machine-to-Machine technology supports several application scenarios, such as smart metering, automotive, healthcare and city monitoring. Smart metering applications have attracted the interest of companies and governments since these applications bring many benefits (e.g. costs reduction and increased reliability) for production, monitoring and distribution of utilities, such as gas, water and electricity. Multi-hop wireless communication is a cost-effective technology for smart metering applications because it extends the wireless range and enables fast deployment. Smart metering data communicated via wireless multi-hop approaches needs mechanisms that makes the communication less vulnerable to security threats and saves the device resources. Data encryption and data aggregation mechanisms emerge as potential solutions to fulfill these requirements. However, the simultaneous execution of data encryption and data aggregation mechanisms is not a trivial task. This is because the data encryption prevents the data aggregation mechanism to summarize the data along the path. Another challenge is to manage both mechanisms according to the concurrent Machine-to-Machine (M2M) applications interests. In this context, we present sMeter, which is a framework that deals with multiple applications interests, avoiding interest conflicts of concurrent users and supporting the management of data aggregation and data encryption. sMeter is implemented using low-cost hardware in an indoor environment. The communication is performed via a wireless multi-hop technology, and the performance of this communication is evaluated in terms of delay, data reception ratio and received signal strength indication.

Artigos de Conferência, Publicação

Model of organization and distribution of applications for software defined networks: SDNrepo

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.

Artigos de Conferência, Publicação

RepoSDN: An repository organization and coordination method of software defined networks applications

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

Artigos de Conferência, Publicação

Context-aware adaptation mechanism for video dissemination over Flying Ad-Hoc Networks

The user experience on watching live video sequences transmitted over a Flying Ad-Hoc Networks (FANETs) must be considered to drop packets in overloaded queues, in scenarios with high buffer overflow and packet loss rate. In this paper, we introduce a context-aware adaptation mechanism to manage overloaded buffers. More specifically, we propose a utility function to compute the dropping probability of each packet in overloaded queues based on video context information, such as frame importance, packet deadline, and sensing relevance. In this way, the proposed mechanism drops the packet that adds the minimum video distortion. Simulation evaluation shows that the proposed adaptation mechanism provides real-time multimedia dissemination with QoE support in a multi-hop, multi-flow, and mobile network environments.

Artigos de Conferência, Publicação

Additions to the ETArch control plane to support multimedia QoS-guaranteed content transport over OpenFlow-enabled SDN future internet systems

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.

Artigos de Conferência, Publicação

Filling the gap between Software Defined Networking and Wireless Mesh Networks

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.

Artigos de Conferência, Publicação

Middleware Group Communication Mechanisms in M2M environments

Machine-to-Machine (M2M) communication is a technology that will bring new horizons for the current concept of smart systems. However, efficient M2M communication requires the design of middleware/platform components able to deal with multiple application requirements and heterogeneous wireless environments. In order to address this challenge, this paper proposes the Communication Manager Component (CMC) to integrate the M2M middleware. CMC enables the management of communication mechanisms, such as data-aggregation, sleep-schedule, uplink-schedule and signaling-aggregation, aiming to save energy and to satisfy multiple application data requests. The management is performed dynamically taking into account the applications requests, the base-station overload indicators and the M2M devices’ status (eg energy level, location).

Artigos de Conferência, Publicação

Flowvisorqos: Aperfeicoando o flowvisor para aprovisionamento e recursos em redes virtuais definidas por software

. 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.

Artigos de Conferência, Publicação

Control of multiple packet schedulers for improving QoS on OpenFlow/SDN networking

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.

Artigos de Conferência, Publicação

Cim-sdn: A common information model extension for software-defined networking

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.

Artigos de Conferência, Publicação

Integrating legacy forwarding environment to OpenFlow/SDN control plane

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.

Artigos de Conferência, Publicação

A quality of experience handover system for heterogeneous multimedia wireless networks

The convergence of emerging real-time multimedia services, the increasing coverage of wireless networks and the ever-growing popularity of mobile devices, are leading to an era of user-centric multimedia wireless services. In this scenario, heterogeneous communications will co-exist and ensure that the end-user is always best connected. However, the Quality of Experience (QoE) support for emerging video applications in multi-operator environments remains a significant challenge and is crucial for the success of wireless multimedia systems. This paper presents a Quality of Experience Handover Architecture for Converged Heterogeneous Wireless Networks, called QoEHand. QoEHand allows users of multimedia content to be always best connected in IEEE 802.11e and IEEE 802.16e environments. Simulation results show the impact and benefit of the proposed solution in multi-access and multi-operator wireless scenarios by using objective and subjective QoE metrics.

Artigos de Conferência, Publicação

Uma proposta de arquitetura para o provisionamento de circuitos dinâmicos sobre redes definidas por software

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.

Artigos de Conferência, Publicação

Ipsflow–uma proposta de sistema de prevençao de intrusao baseado no framework openflow

The ideal Intrusion Prevention System (IPS) is the one that detects malicious traffic across the network and blocks it at its source. Conventional IPSs do not meet these requirements satisfactorily, because when operating in active mode cannot have a wide coverage on the network and just block the passing traffic. And while catching mirrored traffic, it can only block it when working together with switches from the same solution or vendor. In this scenario, this paper presents IPSFlow, an IPS solution for selective and distributed capture with automated blocking of malicious traffic based on OpenFlow.

Artigos de Conferência, Publicação

A mobile qoe architecture for heterogeneous multimedia wireless networks

One of the main requirements in this emerging wireless multimedia era is the Quality of Experience (QoE) assurance for 2D or 3D video applications in heterogeneous multi-operator environments. Therefore, this paper proposes a QoE Architecture for Heterogeneous Multimedia Wireless Networks, called QoEHand. QoEHand extends the Media Independent Handover (MIH)/IEEE 802.21 proposal with QoEawareness, seamless mobility, dynamic class of service mapping and a set of content adaptation schemes. The proposed solution allows the best connection and considers the QoE needs of mobile clients and available wireless resources in IEEE 802.11e and IEEE 802.16e service classes. Simulation experiments were carried out to show the impact and benefits of QoEHand on the user´s perception, by using objective and subjective QoE metrics.

Artigos de Conferência, Publicação

Real-time QoE prediction for multimedia applications in wireless mesh networks

As Wireless Mesh Networks (WMNs) are being increasingly deployed, there is an increasing demand for new quality assessment mechanisms that allow service operators to evaluate and optimize the utilization of network resources, while ensuring a good quality level on multimedia applications as perceived by end-users. However, existing real-time assessment schemes for WMNs are not capable of capturing the actual quality of received multimedia content with regard to user perception. Therefore, it is not possible to assure the user experience of content services. To address this problem, this paper introduces the Hybrid Quality of Experience (HyQoE) Prediction, which is a quality estimator specially designed to assess realtime multimedia applications. HyQoE is designed based on the framework of the widely used Pseudo-Subjective Quality Assessment (PSQA) Tool which exploits Random Neural Network (RNN). Crucial extension work has been implemented to achieve our objectives. A performance evaluation verifies the effectiveness and advantages of HyQoE in predicting users’ perception of multimedia content in WMNs over existing subjective and hybrid methods.

Artigos de Conferência, Publicação

A proposal management of the legacy network environment using OpenFlow control plane

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.

Artigos de Conferência, Publicação

Video quality estimator for wireless mesh networks

As Wireless Mesh Networks (WMNs) have been increasingly deployed, where users can share, create and access videos with different characteristics, the need for new quality estimator mechanisms has become important because operators want to control the quality of video delivery and optimize their network resources, while increasing the user satisfaction. However, the development of in-service Quality of Experience (QoE) estimation schemes for Internet videos (e.g., real-time streaming and gaming) with different complexities, motions, Group of Picture (GoP) sizes and contents remains a significant challenge and is crucial for the success of wireless multimedia systems. To address this challenge, we propose a real-time quality estimator approach, HyQoE, for real-time multimedia applications. The performance evaluation in a WMN scenario demonstrates the high accuracy of HyQoE in estimating the Mean Opinion Score (MOS). Moreover, the results highlight the lack of performance of the well-known objective methods and the Pseudo-Subjective Quality Assessment (PSQA) approach.

Artigos de Conferência, Publicação

FHDRA: Uma Proposta para Reduçao da Latência de Handoff Layer-3 em Redes Sem Fio de Multiplos Saltos

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.

Artigos de Conferência, Publicação

IPSFlow–uma proposta de IPS distribuído para captura e bloqueio seletivo de tráfego malicioso em redes definidas por software

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.

Artigos de Conferência, Publicação

A parametric QoE video quality estimator for Wireless Networks

The development of real-time quality estimator schemes for emerging Internet videos with different content types remains a significant challenge and is crucial for the success of wireless multimedia systems. However, currently in-service assessment schemes fail in capturing subjective aspects of multimedia content related to the user perception. Therefore, this paper proposes an on-the-fly parametric video quality estimator approach (called MultiQoE) for real-time video streaming applications. Experiments in a Wireless Mesh Network (WMN) scenario were carried out to show the accuracy, benefit, and impact of MultiQoE compared to widely used Quality of Experience (QoE) subjective, objective and parametric methods.

Artigos de Conferência, Publicação

A hybrid prediction and assessment quality of experience approach for videostreaming applications over wireless mesh networks

As Wireless Mesh Networks (WMNs) have been increasingly deployed, the need of new quality measurement schemes became essential since operators want to control and optimize their network resources, while keeping users of multimedia applications with a good quality level. However, currently WMN in-service assessment schemes fails in capturing subjective aspects of real-time multimedia content related to the user perception. Therefore, this paper proposes a new on-the-fly quality estimator approach, called Hybrid Quality of Experience (HyQoE) Prediction, for real-time videostreaming applications. Moreover, performance evaluation results present the benefits and accuracy of HyQoE in predicting the user perception compared to well-know subjective and objective methods in a WMN scenario.

Artigos de Conferência, Publicação

Mecanismo para aprovisionamento dinâmico e escalável em redes em malha sem fio para suporte de aplicações com alta demanda de recursos

The success of mobile and ubiquitous computing, coupled with the increasing demand for applications with high Quality of Service (QoS) and Quality of Experience (QoE) requirements, has brought great challenges to the future access networks. Thus, wireless mesh networks distinguish due to its flexibility, redundancy, low-cost and broadband capacity. However, aspects as scalability, availability and reliability, are still challenging. Following the limitations of existing proposals, this paper proposes the Multi-Service Resource Allocation in Wireless Mesh Networks (MIRA-WMN) for provisioning resources of wireless mesh networks compliant with IEEE 802.11 e/s standard. The MIRA-WMN proposes a single solution to integrate QoS control and connectivity resources to support multi-user sessions with high requirements. The MIRA-WMN was evaluated by simulations, which demonstrated its benefits in the data and control plane, as well as user’s perception.

Artigos de Conferência, Publicação

Legacyflow: Bringing openflow to legacy network environments

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, softwares and protocols, in isolation to the production traffic. During rollout, one practical problem arises with legacy switches that do not support the OpenFlow protocol and need to be replaced/upgraded or worked around by means of costly network re-engineering. This poster proposes a new OpenFlow datapath, which is able to interact with non OpenFlow legacy equipment, creating a new approach to hybrid OpenFlow networks.

Artigos de Conferência, Publicação

Pesquisa experimental para a internet do futuro: Uma proposta utilizando virtualização e o frame-work openflow

A Internet é um enorme sucesso mundial e vem mudando a forma como interagimos, trabalhamos e nos divertimos. Boa parte deste sucesso se deve à grande flexibilidade da tecnologia IP. Apesar de todo o sucesso da Internet, a tecnologia básica IP é a causa das suas próprias limitações que se tornam cada vez mais evidentes. Um dos principais objetivos da atividade conhecida como Internet do Futuro (IF) é a formulação e avaliação de arquiteturas alternativas para substituir o protocolo IP. Nesse contexto, duas abordagens estão sendo discutidas e investigadas: a primeira denominada limpa (Clean Slate), que visa substituir a arquitetura atual por uma nova totalmente reconstruída, e a outra chamada evolucionária (Evolutionary) que pretende evoluir a arquitetura atual sem perder a compatibilidade com a anterior.

Artigos de Conferência, Publicação

ETXMULT: A routing metric for multimedia applications in wireless mesh networks

In a near future, wireless mesh networks (WMNs) and multimedia content will be abundant technologies/applications in the Internet. Hence, in order to keep and attract new customers, as well as, reduce operational costs, the development of new quality level control schemes are needed and it is one of the key requirements for the success of next generation wireless multimedia systems. With this goal in mind, this paper presents a new routing metric with focused on estimation error on wireless links, named ETXMULT (Expected Transmission Count for Multimedia Content), to assure high-quality paths on multi-hop wireless networks for multimedia traffic. Simulations were carried out, by using Network Simulator 2 (NS-2), to demonstrate the behavior and benefits of the proposed metric with Optimized Link State Routing (OLSR) routing protocol. The results presented improvements in the distribution of multimedia content compared to the original Expected Transmission Count (ETX) metric, by analyzing well-know QoS and QoE metrics.