In this project, two tests were performed. On the first test, Mininet-WiFi was used to simulate a Software Defined Network to demonstrate Mininet-WiFi’ s ability to be used as the Software Defined Network emulator which can also be integrated to the existing network using a Network Virtualized Function (NVF). A typical organization’s computer network was simulated which consisted of a website hosted on the LAMP (Linux, Apache, MySQL, PHP) virtual machine, and an F5 application delivery controller (ADC) which provided load balancing of requests sent to the web applications. A website page request was sent from the virtual stations inside Mininet-WiFi. The request was received by the application delivery controller, which then used round robin technique to send the request to one of the web servers on the LAMP virtual machine. The web server then returned the requested website to the requesting virtual stations using the simulated virtual network. The significance of these results is that it presents Mininet-WiFi as an emulator, which can be integrated into a real programmable networking environment offering a portable, cost effective and easily deployable testing network, which can be run on a single computer. These results are also beneficial to modern network deployments as the live network devices can also communicate with the testing environment for the data center, cloud and mobile provides. On the second test, a Software Defined Network was created in Mininet using python script. An external interface was added to enable communication with the network outside of Mininet. The amazon web services elastic computing cloud was used to host an OpenDaylight controller. This controller is used as a control plane device for the virtual switch within Mininet. In order to test the network, a webserver hosted on the Emulated Virtual Environment – Next Generation (EVENG) software is connected to Mininet. EVE-NG is the Emulated Virtual Environment for networking. It provides tools to be able to model virtual devices and interconnect them with other virtual or physical devices. The OpenDaylight controller was able to create the flows to facilitate communication between the hosts in Mininet and the webserver in the real-life network. / Electrical and Mining Engineering / M. Tech. (Electrical Engineering)

Software Defined Networking (SDN) has become increasingly popular in combination with Network Function Virtualization (NFV). SDN is a way to make a network more programmable and dynamic. However, in order to create a homogeneous network using this concept, legacy equipment will have to be substituted by SDN equipment, which is costly. To close the gap between the legacy world and SDN, we introduce the concept of a legacy Network Management System (NMS) that is connected to an SDN controller to perform service provisioning. This way, the NMS is capable of configuring both legacy as well as SDN networks to provide customers with the services that they have ordered, while still allowing for new SDN features in the SDN domain of the network. The main service we wish to provide using SDN is Service Function Chaining (SFC). Service provisioning consists of dynamically constructing a path through the ordered network services, in this case Virtual Network Functions (VNFs). This thesis focuses on the SDN controller and its interaction with the NMS. This project aims at configuring OpenFlow rules in the network using an SDN controller to perform SFC. Moreover, the focus will be on how to represent an SDN element and a service function chain in the legacy network NMS. The thesis also contains a discussion on what information should be exchanged between the management software and the controller. The management software used is called BECS, a system developed by Packetfront Software. Integrating SDN in BECS is done by creating a proof of concept, containing a full environment from the low level network elements to the NMS. By using a bottom-up approach for creating this proof of concept, the information that BECS is required to send to the SDN controller can be identified before designing and implementing the connection between these two entities. When sending the information, the NMS should be able to receive acknowledgement of successful information exchange or an error. However, when the proof of concept was created a problem arose on how to test and troubleshoot it. For this reason, a web Graphical User Interface (GUI) was created. This GUI shows the number of packets that have gone through a VNF. Because it is possible to see how many packets go through a VNF, one can see where a network issue occurs. The subsequent analysis investigates the impact of making such a GUI available for a network administrator and finds that the part of the network where the configuration error occurs can be narrowed down significantly. / Software Defined Networking (SDN) har blivit mer och mer populärt i kombination med Network Function Virtualization (NFV). SDN är en sätt för att göra ett nätverk mer programmerbart och dynamiskt. För att skapa ett homogent nätverk med detta koncept, behöver man dock ersätta traditionell utrustning med SDN utrustning som är dyr. För att stänga gapet mellan traditionella nätverk och SDN-världen, introducerar vi ett koncept med ett traditionell Network Management System (NMS) som är anslutet till en SDN-styrenhet för att utföra tjänsteprovisionering. På detta sätt kan NMS:et konfigurera både traditionella och SDN-nätverk, samt provisionera tjänster för kunderna medan nya SDN-funktioner möjliggörs i SDN-delen av nätverket. Den huvudsakliga tjänsten som vi vill lansera genom SDN är Service Function Chaining (SFC). Tjänsteprovisionering består av att konstruera en väg genom beställda tjänster, i detta fall Virtual Network Functions (VNFs). Detta examensarbete fokuserar huvusakligen på SDN-styrenheten och dess interaktion med NMS:et. Projektet syftar till att konfigurera OpenFlow regler i SDN-styrenheten för att utföra SFC. Dessutom fokuserar arbetet på hur man kan representera SDN-element och SFCs i ett traditionellt NMS. Vidare diskuteras vilken information som ska utbytas mellan NMS:et och SDNstyrenheten. NMS:et som ska vara användas är BECS, ett system utvecklat av Packetfront Software. Uppgiften löses genom att skapa ett proof of concept, som innehåller ett komplett system med alla komponenter från nätverkselement till NMS:et. Genom att använda en bottom-up-strategi för detta proof of concept kan informationen som BECS måste skicka till SDN styrenheten indentifieras, innan design och implementation av förbindelsen mellan enheterna kan utföras. När informationen är skickad ska NMS:et kunna hämta information om huruvida styrenheten fick informationen utan fel. Dock uppstår ett problem gällande hur man testar och felsöker detta proof of concept. Av denna anledning skapades ett web Graphical User Interface (GUI). Användargränssnittet visar antalet paket som går genom varje VNF, samt var i nätverket fel uppstår. Analysen undersöker hur stor effekten är för en nätverkadministrator och visar att området där fel kan uppstå begränsas avsevärt.

Cloud Infrastructure-as-a-Service (IaaS) is a form of utility computing which has emerged with the recent innovations in the service computing and data communication technologies. Regardless of the fact that IaaS is attractive for application service providers, satisfying user requests while ensuring cloud operational objectives is a complicated task that raises several resource management challenges. Among these challenges, limited controllability over network services delivered to cloud consumers is prominent in single datacenter cloud environments. In addition, the lack of seamless service migration and optimization, poor infrastructure utilization, and unavailability of efficient fault tolerant techniques are noteworthy challenges in geographically distributed datacenter clouds. Initially in this thesis, a datacenter resource management framework is presented to address the challenge of limited controllability over cloud network traffic. The proposed framework integrates network virtualization functionalities offered by software defined networking (SDN) into cloud ecosystem. To provide rich traffic control features to IaaS consumers, control plane virtualization capabilities offered by SDN have been employed. Secondly, a quality of service (QoS) aware seamless service migration and optimization framework has been proposed in the context of geo-distributed datacenters. Focus has been given to a mobile end-user scenario where frequent cloud service migrations are required to mitigate QoS violations. Finally, an SDN-based dynamic fault restoration scheme and a shared backup-based fault protection scheme have been proposed. The fault restoration has been achieved by introducing QoS-aware reactive and shared risk link group-aware proactive path computation algorithms. Shared backup protection has been achieved by optimizing virtual and backup link embedding through a novel integer linear programming approach. The proposed solutions significantly improve bandwidth utilization in inter-datacenter networks while recovering from substrate link failures.

This is a Masters student Final Dissertation / In this project, two tests were performed. On the first test, Mininet-WiFi was used to simulate a Software Defined Network to demonstrate Mininet-WiFi’ s ability to be used as the Software Defined Network emulator which can also be integrated to the existing network using a Network Virtualized Function (NVF). A typical organization’s computer network was simulated which consisted of a website hosted on the LAMP (Linux, Apache, MySQL, PHP) virtual machine, and an F5 application delivery controller (ADC) which provided load balancing of requests sent to the web applications. A website page request was sent from the virtual stations inside Mininet-WiFi. The request was received by the application delivery controller, which then used round robin technique to send the request to one of the web servers on the LAMP virtual machine. The web server then returned the requested website to the requesting virtual stations using the simulated virtual network. The significance of these results is that it presents Mininet-WiFi as an emulator, which can be integrated into a real programmable networking environment offering a portable, cost effective and easily deployable testing network, which can be run on a single computer. These results are also beneficial to modern network deployments as the live network devices can also communicate with the testing environment for the data center, cloud and mobile provides. On the second test, a Software Defined Network was created in Mininet using python script. An external interface was added to enable communication with the network outside of Mininet. The amazon web services elastic computing cloud was used to host an OpenDaylight controller. This controller is used as a control plane device for the virtual switch within Mininet. In order to test the network, a webserver hosted on the Emulated Virtual Environment – Next Generation (EVENG) software is connected to Mininet. EVE-NG is the Emulated Virtual Environment for networking. It provides tools to be able to model virtual devices and interconnect them with other virtual or physical devices. The OpenDaylight controller was able to create the flows to facilitate communication between the hosts in Mininet and the webserver in the real-life network / The University of South Africa The University of Johannesburg / College of Engineering, Science and Technology

Revolutionary mobile technologies, such as high-speed packet access 3G (HSPA+) and LTE, have significantly increased mobile data rate over the radio link. While most of the world looks at this revolution as a blessing to their day-to-day life, a little-known fact is that these improvements over the radio access link results in demanding tremendous improvements in bandwidth on the backhaul network. Having said this, today's Internet Service Providers (ISPs) and Mobile Network Operators (MNOs) are intemperately impacted as a result of this excessive smartphone usage. The operational costs (OPEX) associated with traditional backhaul methods are rising faster than the revenue generated by the new data services. Building a mobile backhaul network is very different from building a commercial data network. A mobile backhaul network requires (i) QoS-based traffic with strict requirements on delay and jitter (ii) high availability/reliability. While most ISPs and MNOs have promised advantages of redundancy and resilience to guarantee high availability, there is still the specter of failure in today's networks. The problems of network failures in today's networks can be quickly but clearly ascertained. The underlying observation is that ISPs and MNOs are still exposed to rapid fluctuations and/or unpredicted breakdowns in traffic; it goes without saying that even the largest operators can be affected. But what if, these operators could now put in place designs and mechanisms to improve network survivability to avoid such occurrences? What if mobile network operators can come up with low-cost backhaul solutions together with ensuring the required availability and reliability in the networks? With this problem statement in-hand, the overarching theme of this dissertation is within the following scopes: (i) to provide low-cost backhaul solutions; the motivation here being able to build networks without over-provisioning and then to bring-in new resources (link capacity/bandwidth) on occasions of unexpected traffic surges as well as on network failure conditions for particularly ensuring premium services (ii) to provide uninterrupted communications even at times of network failure conditions, but without redundancy. Here a slightly greater emphasis is laid on tackling the 'last-mile' link failures. The scope of this dissertation is therefore to propose, design and model novel network architectures for improving effective network survivability and network capacity, at the same time by eliminating network-wide redundancy, adopted within the context of mobile backhaul networks. Motivated by this, we study the problem of how to share the available resources of a backhaul network among its competitors, with whom a Service Level Agreement (SLA) has been concluded. Thus, we present a systematic study of our proposed solutions focusing on a variety of empirical resource sharing heuristics and optimization frameworks. With this background, our work extends towards a novel fault restoration framework which can cost-effectively provide protection and restoration for the operators, enabling them with a parameterized objective function to choose desired paths based on traffic patterns of their end-customers. We then illustrate the survivability of backhaul networks with reduced amount of physical redundancy, by effectively managing geographically distributed backhaul network equipments which belong to different MNOs using 'logically-centralized' physically-distributed controllers, while meeting strict constraints on network availability and reliability

No description available.

Submitted by Milena Rubi (milenarubi@ufscar.br) on 2017-10-09T14:35:22Z No. of bitstreams: 1 FRATE_Marcelo-2017.pdf: 8466810 bytes, checksum: 9438c26c84ebe90cd741672c8c04d726 (MD5) / Approved for entry into archive by Milena Rubi (milenarubi@ufscar.br) on 2017-10-09T14:35:33Z (GMT) No. of bitstreams: 1 FRATE_Marcelo-2017.pdf: 8466810 bytes, checksum: 9438c26c84ebe90cd741672c8c04d726 (MD5) / Approved for entry into archive by Milena Rubi (milenarubi@ufscar.br) on 2017-10-09T14:35:45Z (GMT) No. of bitstreams: 1 FRATE_Marcelo-2017.pdf: 8466810 bytes, checksum: 9438c26c84ebe90cd741672c8c04d726 (MD5) / Made available in DSpace on 2017-10-09T14:35:53Z (GMT). No. of bitstreams: 1 FRATE_Marcelo-2017.pdf: 8466810 bytes, checksum: 9438c26c84ebe90cd741672c8c04d726 (MD5) Previous issue date: 2017-02-23 / Não recebi financiamento / Since the emergence of the Software-Defined Networking (SDN), and, more precisely, since the development of an open interface in 2008 called OpenFlow protocol, it is being observed that this new networking paradigm is deeply remodeling the IP-protocol- based networks. It means that new mechanisms of provision services are being possible, which ensures scalability and reduces costs. Although this new paradigm has been created to centralize the control logic, there is the possibility of decentralizing it through the parceling of control tasks between two or more controllers. In this scenario, the subdivision of administrative domain in smaller subdomains in order to have each of them being controlled by one single controller has been an alternative to ensure scalability in SDN. The OpenFlow protocol allows communication among switches and controllers to another controller. However, the protocol does not define how this communication between one controller to other should be done. It is mandatory, therefore, the development of protocol independent solutions able to distribute this logic inside the same administrative domain. New proposals have been arisen, but their applications either use equal controllers or demand the development of new controllers specifically designed. This master’s research aims to offer the fundamentals to the development of an architecture here so called Orch Flow, able to receive application demands and organize them in a way it provides requested services through an OpenFlow network designed with two or more different implementation controllers. The OrchFlow architecture that is being proposed accomplishes its task through handling multiple OpenFlow controllers hierarchically and providing network access through three distinct modes: Proactive, Reactive and Hybrid. / Desde o surgimento das Redes Definidas por Software e mais especificamente à partir de 2008 com o desenvolvimento de uma interface aberta, o protocolo OpenFlow, é possível observar que este novo paradigma de redes está revolucionando as redes baseadas no protocolo IP, possibilitando a criação de novos mecanismos de aprovisionamento de serviços, garantindo a escalabilidade e reduzindo custos. Embora este novo paradigma tenha sido criado para a centralização da lógica de controle, existe a possibilidade de descentralizá-la através da divisão das tarefas de controle entre dois ou mais controladores. Neste cenário, subdividir o domínio administrativo em subdomínios menores e fazer com que cada subdomínio seja controlado por um controlador tem sido uma alternativa para garantir escalabilidade em Software-Defined Networking (SDN). O protocolo OpenFlow permite a comunicação entre switches e controladores, entretanto ele não define como deve ser feita a comunicação de um controlador para outro controlador. Faz-se necessário, portanto, o desenvolvimento de soluções independentes do protocolo, capazes de distribuir essa lógica dentro de um mesmo domínio administrativo. Neste cenário, novas propostas vão surgindo, porém as aplicações desenvolvidas ou fazem uso de controladores iguais ou são criados novos controladores especificamente para essa finalidade. Esta pesquisa de mestrado tem como objetivo o desenvolvimento de uma arquitetura, aqui denominada de OrchFlow, capaz de receber solicitações de aplicações, orquestrando as requisições a fim de prover os serviços solicitados numa rede OpenFlow com dois ou mais controladores de implementações diferentes. A arquitetura OrchFlow, desenvolvida para esta pesquisa de mestrado, realiza essa tarefa através da orquestração de múltiplos controladores OpenFlow atuando de forma hierárquica, provendo o acesso à infraestrutura da rede através de três modos distintos: o Proativo, o Reativo e o Híbrido.

Pessoas e organizações ao redor do globo utilizam aplicações multimídia para interação e comunicação. Existe notável crescimento de tráfego característico dessas aplicações, uma vez que há convergência de voz e dados para um modelo único de transporte. As redes de computadores, por suportar tais aplicações cadenciam desafios e oportunidades de negócios que os operadores têm aproveitado. Por outro lado, os usuários experimentam serviços com qualidades cada vez mais refinados, mesmo assim, existem aspectos que devem ser tratados para elevar a qualidade de experiência percebida pelos usuários ao consumir serviços ofertados sobre a internet. Métricas de QoS usualmente são baseadas nos usuários ou na rede, por isso, conceitos como NFV e SDN permitem aprimorar e expandir a perspectiva de oferta de uma camada de abstração para desenvolvimento de soluções flexíveis, que visam lidar com aplicações multimídia ofertadas em nuvem. Não obstante, a construção dessas soluções deve ser calcada em aspectos intrínsecos ao conceito de Internet do Futuro que preconiza soluções virtualizadas, flexíveis, convergentes, escaláveis, orientadas a contexto, seguras e melhor gerenciadas. Este trabalho propõe uma abordagem para mitigar a distância das aplicações com os recursos de rede e computação. Usualmente as aplicações desconhecem características de hardware sobre o qual elas operam; quanto a rede, mesmo com esforços em vários níveis da pilha de protocolos, desconhece especificidades das aplicações em execução. Há também dificuldade de gerenciamento global de recursos, integração de políticas e acordos de serviço entre operadores. O trabalho visa adicionar uma camada de gerenciamento para elevar os níveis de QoS para aplicações multimídia baseadas em NFV. Para realizar isso, é proposto uma entidade que atua no plano de dados e controle, capaz de orquestrar recursos de rede e de computação simultaneamente para aprimorar QoS em aplicações multimídia. A incorporação dessa entidade conquista melhoramento de QoS por meio da oferta de resiliência na comunicação fim-a-fim de entidades consumidoras dessas aplicações, provê um balanceamento de carga adequado a fim de não comprometer parâmetros de QoS como tempo de resposta, provê escalabilidade sob demanda, promove o conceito de inspeção de pacotes para segmentação de políticas de rede orientada à aplicação, finalmente realiza a separação de plano de dados e controle. A construção e experimentação da solução permitiu diminuir tempos de resposta nas aplicações multimídia; a solução reagiu adequadamente frente a cargas de trabalho heterogêneas no sentido de prover confiabilidade para garantia de QoS; também, o conceito de inspeção de pacotes foi capaz de atuar para diminuir a distância que as aplicações possuem da rede e o hardware sobre o qual elas operam. / People and organizations around the globe use multimedia applications for interaction and communication. There is notable traffic growth characteristic of these applications since there is a convergence of voice and data for a single transport model. Computer networks, because they support such applications, meet the challenges and business opportunities that operators have taken advantage of. On the other hand, users use services with increasingly refined qualities, nevertheless, there are aspects that must be addressed to raise the quality of experience for users when consuming services offered over the internet. QoS metrics are usually user-based or network-based, hence concepts such as NFV and SDN allow to improve and expand the perspective of offering an abstraction layer for the development of flexible solutions that deal with multimedia applications offered in the cloud. Nevertheless, the construction of these solutions must be based on intrinsic aspects to the Future Internet concept that advocates virtualized solutions, flexible, convergent, scalable, context-aware, secure and better managed. This dissertation proposes an approach to mitigate the distance of the applications with the resources of compute and network. Usually, the applications are unaware of the hardware characteristics on which they operate, as for the network, even with several efforts at various levels of the protocol stack, the specificities of running applications are unknown. There is also challenges of managing global resources, integrating policies and service agreements between operators. This work aims to add a management layer to raise the levels of QoS for multimedia applications based on NFV. To accomplish this, an entity that acts on the data and control plane is proposed, capable of orchestrating network and computing resources simultaneously to enhance QoS in multimedia applications. The incorporation of this entity achieves QoS improvement through resiliency in the end-to-end communication of the consumer entity of these applications, provides adequate load balancing in order to avoid compromising QoS parameters such as response time, provides on-demand scalability, improves the concept of package inspection for the segmentation of application-oriented network policies, and finally performs the separation of data and control plane. The construction and experimentation of the solution allowed to reduce response times in the multimedia applications. The solution reacted adequately to heterogeneous workloads in order to provide reliability for QoS guarantee. Furthermore, the concept of packet inspection was able to act to decrease the distance that the applications have from the network and the hardware on which they operate. / Dissertação (Mestrado)

Fundação de Apoio a Pesquisa e à Inovação Tecnológica do Estado de Sergipe - FAPITEC/SE / With the popularity of the Internet and the emergence of new services, it has become increasingly necessary to make a network planning, in order to ensure that each of the elements that compose it are used e ciently. Moreover, it is necessary to control and monitor the network, making sure that everything is running the way it was planned. In networks using the SDN paradigm, by introducing a network controller, is possible the separation between the data plane (hardware) and control plane (software) existing on the network devices, allowing that new protocols and technologies are implemented and tested on any network device, regardless of its manufacturer. In contrast with it, the following question arises: how to apply tra c monitoring in an SDN network ahead of his centralized control architecture without causing delays or inconsistencies? This work proposed a tra c monitoring service for SDN networks based on the OpenFlow protocol, called SDNMonitor, which aims to provide a view of network data tra c at three levels of granularity, for each port of each switch, for each flow and for each network service. Additionally, it was also proposed a load balancing service based on the use of Round-Robin and Bandwidth-Based algorithms. The experimental evaluation of these services was conducted through controlled experiments, which were generated and monitored some tra c. The results showed that the SDNMonitor service could monitor the network tra c in the three levels of granularity without impacting negatively on its operation, and that the load balancing service has been able to improve network tra c. / Com a popularidade da Internet e a emergência de novos serviços, tornou-se cada vez mais necessário fazer um planejamento da rede, com o objetivo de assegurar que cada um dos elementos que a compõem sejam utilizados de forma eficiente. Além disso, é necessário controlar e monitorar a rede, verificando se tudo está sendo executando da maneira que foi planejada. Em redes que utilizam o paradigma SDN, através da introdução de um controlador de rede, é possível a separação entre o plano de dados (hardware) e o plano de controle (software) existentes nos dispositivos de rede, permitindo que novos protocolos e novas tecnologias sejam implementadas e testadas em qualquer dispositivo de rede, independente do seu fabricante. Em contrapartida, surge o seguinte questionamento: como aplicar monitoramento de tráfego em uma rede SDN diante da sua arquitetura de controle centralizada sem causar atrasos ou inconsistências? Este trabalho propôs um serviço de monitoramento de tráfego em redes SDN baseado no protocolo OpenFlow, chamado SDNMonitor, que tem como principal objetivo prover uma visão do tráfego de dados da rede em três níveis de granularidade, por cada porta de cada switch, por cada fluxo e por cada serviço de rede. Adicionalmente, também foi proposto um serviço de balanceamento de carga, baseado na utilização dos algoritmos Round-Robin e Bandwidth-Based. A avaliação experimental destes serviços foi realizada através de experimentos controlados, onde foram gerados e monitorados alguns tráfegos. Os resultados demonstraram que o serviço SDNMonitor conseguiu monitorar o tráfego da rede nos três níveis de granularidade sem impactar de forma negativa no seu funcionamento, e que o serviço de balanceamento de carga foi capaz de melhorar o tráfego da rede.

Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2015-03-27T14:11:27Z No. of bitstreams: 2 Dissertação - Mário Augusto da Cruz - 2014.pdf: 990265 bytes, checksum: 491a60613f98d994e59969035aa281ca (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2015-03-27T14:49:41Z (GMT) No. of bitstreams: 2 Dissertação - Mário Augusto da Cruz - 2014.pdf: 990265 bytes, checksum: 491a60613f98d994e59969035aa281ca (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2015-03-27T14:49:41Z (GMT). No. of bitstreams: 2 Dissertação - Mário Augusto da Cruz - 2014.pdf: 990265 bytes, checksum: 491a60613f98d994e59969035aa281ca (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2014-12-16 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Software Defined Networking represents a new paradigm that eases the operation, monitoring and network managing through the decoupling between the control plane and the data plane. However, in this new context, some classic solutions in the network monitoring field need to be revisited, as there are new constraints, but there are also new opportunities. In monitoring context, one strategy commonly used, mainly in high capacity networks, is the tracking of the most frequent items, also known as heavy hitters. One approach to monitoring the most frequent items consists in detecting the hierarchical heavy hitters, which allows an efficient real time monitoring. In this work, we propose and evaluate a new monitoring solution capable of online detection of hierarchical heavy hitters, using the characteristics of software defined networks, in special the OpenFlow protocol. Our proposal, combines a flexible accounting of flow rules, from OpenFlow switches, with inspection of traffic samples through a dedicated device. We evaluate our proposal in a simulated and emulated environments, both using packet traces generated artificially and also from real networks. The results show that our proposal has satisfactory accuracy and low convergence time in comparison to a previous solution to OpenFlow networks, in addition to identify heavy hitters in two dimensions. / As Redes Definidas por Software representam um novo paradigma que flexibiliza a operação, o monitoramento e a gerência de redes através do desacoplamento entre o plano de controle e o plano de dados. No entanto, nesse novo contexto, algumas soluções clássicas da área de monitoramento de redes precisam ser revistas, pois há novas restrições, mas também novas oportunidades. No contexto de monitoramento, uma estratégia comumente utilizada, sobretudo em redes de alta capacidade, é o acompanhamento dos itens mais frequentes, também conhecidos como heavy hitters. Uma das abordagens para monitoramento dos itens mais frequentes consiste em detectar as agregações hierárquicas de fluxos, a qual possibilita realizar um monitoramento eficiente em tempo real. Neste trabalho, propomos e avaliamos uma nova solução de monitoramento capaz de detectar de maneira online as agregações hierárquicas de fluxos, utilizando características de redes definidas por software, em especial do protocolo OpenFlow. Nossa proposta, combina uma contabilização flexível de regras de fluxos, proveniente dos comutadores OpenFlow, com uma inspeção de amostras de tráfego através de um dispositivo dedicado. Avaliamos nossa proposta em ambientes simulado e emulado, utilizando traces de pacotes gerados artificialmente e também de redes reais. Os resultados mostram que nossa proposta possui uma acurácia satisfatória e baixo tempo de convergência em comparação a uma solução anterior para redes OpenFlow, além de identificar heavy hitters em duas dimensões.