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

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

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

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

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

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.

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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.

Artigos de Conferência, Publicação

A multimedia-based fuzzy queue-aware routing approach for wireless mesh networks

The proliferation of multimedia content and Wireless Mesh Networks (WMNs) are changing the Internet facilities and life style of fixed and mobile users. For the success of the next generation wireless networks, novel multimedia approaches with quality level assurance are required to allow the distribution of video-streaming, video conference, gaming, multimedia social networking, green multimedia content and other entrainment applications for thousand of users in ubiquitous wireless (mesh) systems. In this context, new routing schemes are needed to provide end-to-end Quality of Service (QoS) and Quality of Experience (QoE) support for delay/loss/jitter-sensitive multimedia applications in WMNs. The well-known OLSR (Optimized Link State Routing) protocol with ETX (Expected Transmission Count) metric bring many benefits for the path selection process, but present a drawback in the queue availability management and reduce the system performance. Therefore, multimedia-related packets will suffer with loss/delay/jitter and the system overall performance will decrease. This paper proposes the Queue-based OLSR ETX (QoETX) approach to overcome the limitations of OLSR-ETX regarding queue availability by using a cross-layer scheme and supporting QoS and QoE assurance. QoETX optimizes network and user-based parameters by coordinating queue availability, QoS and fuzzy issues in the routing decision process as a way to allocate the best paths for multimedia applications. In order to present the benefits of the proposed solution compared with existing routing schemes, namely OLSR-ETX, OLSR-FLC, OLSR-MD and HWMP (IEEE 802.11s standard), regarding QoS (block probability and throughput) and QoE (PSNR, SSIM, VQM and MOS) parameters, performance evaluations were carried by using the Network Simulator (NS-2.34).

Artigos de Conferência, Publicação

Abaré: Um framework para implantação, monitoramento e gerenciamento coordenado e autônomo para redes em malha sem fio

The Wireless Mesh Networks (WMNs) have been gaining ground as a solution to provide last mile indoors and outdoors Internet access, because of their technical and economic feasibility. However, the existence of open source and proprietary approaches that are not interoperable and the delay in the standardization process make deployment of a large-scale WMN timeconsuming and complex. This paper presents an extension of the framework Abaré with autonomic capability and performance evaluation results regarding load balance issues. Abaré defines a set of components and practices in order to optimize the implementation and management of WMN systems, as well as to provide autonomic features in routers to decrease and facilitate the manager workload.

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Cálculo do Tempo de Ajuste em Redes Ópticas Comutadas por Rajadas Baseadas na Sinalização JET

O tempo de ajuste em redes de comutação de rajadas ópticas (OBS) pode ser estimado de forma aleatória ou através de cálculos. Este artigo propõe alternativas para o cálculo do tempo de ajuste em redes OBS, buscando minimizar a probabilidade de bloqueio das rajadas. Para validar a proposta foram realizadas simulações utilizando a plataforma NS-2 (Network Simulator) com diferentes topologias e cenários. Os resultados mostram que o cálculo do tempo de ajuste através de uma distribuição exponencial apresenta os melhores resultados.

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Dimensionamento de Túneis LSPs Através da Ferramenta GLASS: Uma Proposta de Implementação de um Novo Módulo de Re-roteamento Dinâmico

O GLASS (GMPLS Lightwave Agile Switching Simulator) é uma ferramenta de simulação para Redes Ópticas de Nova Geração, livre e de código aberto, desenvolvida em Java. Este artigo visa apresentar uma nova funcionalidade no simulador para facilitar o re-roteamento dinâmico de LSPs (Label Switched Paths) em cenários de redes GMPLS, baseado no protocolo de sinalização RSVP-TE.

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Gerenciamento Dinâmico de Qualidade de Serviço em Redes OBS Baseadas no GMPLS

Este artigo apresenta uma proposta de gerenciamento dinâmico de Qualidade de Serviço (QoS), em redes ópticas que utilizam o paradigma de comutação de rajadas ópticas (OBS) baseadas no GMPLS. Nessa proposta, agentes de monitoração são utilizados para verificar a qualidade de serviço oferecida às classes de rajadas e executar mecanismos reativos para garantir níveis absolutos de desempenho e, através da engenharia de tráfego do GMPLS, oferecer recursos ociosos a fluxos cujo nível de serviço não esteja sendo obedecido. Resultados de simulação mostram que a proposta é capaz de reduzir a probabilidade de bloqueio dos fluxos de rajadas na ocorrência de quebras de contexto.

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Providing Quality of Service for Mesh Networks Using Link Delay Measurements

One of the main problems faced by ad hoc networks is providing specific quality of service guarantees for multimedia applications, mainly due to factors such as radio signal fading and node mobility. Since mesh networks are a special type of ad hoc network, they inherit these networks’ problems. This paper’s main goal is to present OLSR-MD, an extension to OLSR (Optimized Link State Routing), to provide quality of service based on link delay measurements. An evaluation of OLSR-MD in a mesh network to be deployed at the Federal University of Pará, by means of ns2 (version 2.30) simulations, showed that this protocol performed better than other OLSR-based alternatives studied in the simulations.

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Soluções de Monitoramento de Redes Blockchain: Uma Revisão Sistemática da Literatura

Diante do aumento do uso de tecnologias blockchain por partes verticais da indústrias, surge a necessidade do monitoramento eficiente destas redes, para preservação da qualidade deste serviço. Este trabalho tem como objetivo investigar e documentar as informações sobre os sistemas de monitoramento presentes na literatura. Os resultados revelam a predominância de sistemas de monitoramento centralizados, apresentando oito módulos distintos e variadas métricas monitoradas. Desta forma, este estudo apresenta as alternativas de sistemas de monitoramento blockchain presentes na literatura, fornecendo insights valiosos para o desenvolvimento de estratégias mais eficientes e abrangentes para a área.

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A Blockchain-based Approach for Continuous Auditing in IT Change Management

Information Technology (IT) changes are a critical part of the day-to-day operations of most modern organizations, and poor change delivery can pose severe risks to business continuity. In this context, frameworks like COBIT seek to provide guidance for best practices and procedures for proper IT change management, and shareholders often resort to auditing to ensure change delivery following defined procedures. To this end, third-party audit companies perform periodic inspections of the target IT system, log of changes deployed, etc. However, the sheer volume of changes, ever-increasing change complexity, and automation make it challenging to deliver change auditing between inspection events. To tackle this issue, we propose in this paper a blockchain-based approach for continued IT change auditing. In summary, we instrumented a change orchestration framework with a solution for certifying each change deployed in the target system through blockchain. The chain of IT changes in between inspection events is then used to ensure that only certified changes were deployed in the infrastructure.

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Detecção On-line e Antecipada de Ataques à Rede usando Matrix Profile

Na era digital, a crescente sofisticação e variedade de ameaças cibernéticas destacam a importância de fortalecer a cibersegurança para proteger as redes atuais. Este estudo propõe uma abordagem para a detecção antecipada de ataques, utilizando a técnica Matrix Profile (MP) para analisar de forma online fluxos de dados de rede como séries temporais. Este método concentra-se na identificação de anomalias na rede como indicadores de ataques de rede, abordando as limitações dos sistemas de Aprendizado de Máquina existentes que dependem predominantemente de treinamento offline e têm dificuldades em reconhecer padrões de ataques novos ou não treinados. Nossa proposta foi avaliada em diversos cenários de ataque, demonstrando métricas de desempenho superiores quando comparado com métodos tradicionais como CUSUM, EWMA e ARIMA.

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qIDS: Sistema de Detecção de Ataques baseado em Aprendizado de Máquina Quântico Híbrido

A ascensão da utilidade quântica no campo da computação quântica apresenta não apenas desafios, mas também oportunidades para aprimorar a segurança de redes. Esta mudança de paradigma nas capacidades computacionais permite o desenvolvimento de soluções avançadas para contrapor a rápida evolução dos ataques de rede. Aproveitando este avanço tecnológico, este trabalho apresenta o qIDS, um Sistema de Detecção de Intrusão (IDS) que integra de forma inovadora abordagens de computação quântica e clássica. O qIDS utiliza técnicas de Aprendizado de Máquina Quântico (QML) para aprender efetivamente os comportamentos da rede e identificar atividades maliciosas. Ao realizar avaliações experimentais abrangentes em conjuntos de dados públicos, evidenciou-se a competência do qIDS na detecção de ataques, destacando-se, tanto em tarefas de classificação binária quanto multiclasse. Nossos resultados revelam que o qIDS compete favoravelmente com métodos de Aprendizado de Máquina clássicos, destacando o potencial das soluções de cibersegurança aprimoradas por tecnologia quântica na era da utilidade quântica.

Artigos de Conferência, Publicação

ReqRoute: Protocolo de Roteamento por Reforço para Redes de Entrelaçamento Quântico

A Internet Quântica tem como objetivo possibilitar a comunicação quântica entre múltiplos pontos da rede, oferecendo aplicações como a distribuição quântica de chaves (QKD), computação quântica distribuída e as redes de entrelaçamento. No entanto, a tecnologia de comunicação quântica atual apresenta desafios significativos, com baixas taxas de geração de entrelaçamento (pares EPR), capacidade de memória quântica limitada e taxas de decoerência que frequentemente resultam em pares EPR inutilizáveis devido à baixa fidelidade. Isso representa um desafio significativo para tarefas como o roteamento. Neste artigo, é proposto o ReqRoute, um protocolo baseado em aprendizado por reforço para otimizar as decisões de roteamento em redes de entrelaçamento quântico. Demonstrou-se que o ReqRoute supera consistentemente métodos tradicionais, mantendo rotas de maior fidelidade em diversos cenários de configuração de rede.

Artigos de Conferência, Publicação

OTTx: Transações de Uso Único para Serviços Blockchain

Em redes de negócios empresariais, a troca segura de informações entre organizações com objetivos diversos é comum. Usuários, identificados de forma única, acessam recursos por meio de aplicativos confiáveis. A integração de aplicativos de organizações externas introduz elementos não confiáveis e requer mecanismos para garantir privacidade, integridade e não repúdio. Este trabalho propõe um protocolo de Transações Únicas (OTTx) em Blockchains. Ele aborda a necessidade de autenticação segura de transações, revisa o estado da arte e avalia o OTTx em uma Blockchain permissionada. Os resultados mostram que o OTTx garante segurança, privacidade, integridade e não repúdio para transações envolvendo identidades externas, com desempenho satisfatório e baixa sobrecarga de rede. Esta contribuição avança o conhecimento em Blockchains, fornecendo uma solução eficaz para transações envolvendo participantes de rede não confiáveis.

Artigos de Conferência, Publicação

Mitigação Inteligente de Ataques DDoS em Redes O-RAN Utilizando Aprendizado de Máquina

A transição das redes móveis para o 5G estimulou a adoção de tecnologias como NFVs, SDN, slices e de padrões abertos e interoperáveis como o Open RAN (O-RAN). Em relação à segurança, as redes O-RAN se encontram nos estágios iniciais para garantir a integridade e confiabilidade. Diante deste cenário, este trabalho propõe o SID-xApp (Slice Intelligent Defender xApp), uma aplicação integrada ao controlador de quase tempo real da rede (Near-RT RIC), com o objetivo de identificar e mitigar ataques DDoS que possam comprometer os slices presentes na O-RAN. A solução proposta é projetada para permitir o desenvolvimento de forma modular e suportar o recebimento de métricas dos dispositivos conectados à rede, identificar padrões por meio de modelos de aprendizado de máquina (AM) e desassociar usuários mal-intencionados, proporcionando uma camada de segurança ao open fronthaul da O-RAN.

Artigos de Conferência, Publicação

Alocação de Recursos em Redes de Distribuição Quântica de Chaves Multiprotocolo

À medida que a criptografia quântica avança, torna-se cada vez mais importante desenvolver métodos que aprimorem a utilização de recursos em redes de Distribuição Quântica de Chaves (QKD). Enfrentando o desafio de agendar e alocar eficientemente as requisições em redes QKD, este estudo propõe uma abordagem para redes QKD multiprotocolo usando estratégias de roteamento e agendamento conscientes de recursos. Nossa proposta foca em melhorar a eficiência no uso de chaves quânticas, rotas e requisições, enquanto suporta vários protocolos de comunicação quântica. Utilizando duas topologias de redes QKD reais, a proposta foi avaliada em dois cenários de aplicação, com diferentes distribuições de requisições de aplicações de autenticação e criptografia. Avaliou-se o impacto da capacidade de qubit e quantidade de requisições. Os resultados demonstram a viabilidade de nossa abordagem em diversos ambientes.