Link Aggregation Control Protocol on Software Defined Network

A physical connection of computer network must be made reliably. Breaking connection will cause communication between nodes (for example routers, switches, hosts) can be disconnected. One of the solutions is implemention of link aggregation (LA). LA integrates several of physical ports together to make a single logical communication link. Accordingly, there is load sharing traffic among the member port of the group, high-throughput increasing via a single link, and redundancy providing for broken links. We present the implementation of link aggregation using Ryu controller on Software Defined Network (SDN) topology. The results show that the implementation of SDN with OpenvSwitch and Ryu controller can successfully run link aggregation function to solve the problem of link failure

Conectividade definida por software em ambientes móveis

Broadband Internet access on trains has become an expected service for passengers, and the rise in quality demand has been posing a challenge to service providers. There are solutions for Internet access on trains that lack the flexibility and redundancy needed for an improved QoS in the network. Thus, this dissertation studies two new load balancing solutions, one distributed and the other centralized. In an emulated train network, routers of each car communicate their network statistics to other nodes of the network, to be used in load balancing decisions. In the distributed solution, each router has the capacity to make load balancing decisions, while in the centralized solution, an onboard controller makes those decisions. The latter solution is based on load balancing in an SDN environment. In this system, a remote entity aggregates the passengers’ traffic and forwards it to an external network, or to the Internet. The systems must provide an improved quality of experience to the passengers on the train and the total avaliable bandwidth should be distributed evenly by all cars. Requirements were established for the systems, which were developed after an in-depth analysis of solutions for Internet access on board found in the literature. After obtaining the results of the performance tests, it was concluded that the systems improve the QoE of the passengers, as long as the network conditions are approximately constant for an extended period.O acesso à Internet de banda larga em comboios tornou-se num serviço esperado por parte dos passageiros e o aumento na exigência de qualidade tem constituído um desafio para os prestadores de serviços. Existem soluções de acesso à Internet em comboios que carecem da flexibilidade e redundância necessárias para uma melhor qualidade de serviço na rede. Assim, esta dissertação estuda duas novas soluções de balanceamento de carga, uma distribuída e outra centralizada. Numa rede de comboio emulada, routers de cada carruagem comunicam as suas estatísticas de rede para outros nós da rede, para posteriormente serem tomadas decisões de balanceamento de carga. Na solução distribuída, cada router tem capacidade de tomar decisões de balanceamento de carga, enquanto que na solução centralizada, um controlador dentro do comboio toma essas decisões. Esta última solução baseiase num balanceamento de carga em ambiente SDN. Neste sistema, uma entidade remota agrega o tráfego dos passageiros e encaminha-o para uma rede externa, ou para a Internet. Os sistemas devem proporcionar uma qualidade de experiência melhorada aos passageiros do comboio e a largura de banda total disponível deve ser distribuída mais uniformememente por todas as carruagens. Requisitos foram estabelecidos para os sistemas, que foram desenvolvidos após uma análise aprofundada das soluções de acesso à Internet em comboios encontradas na literatura. Após a obtenção dos resultados dos testes de desempenho, concluiu-se que as duas soluções melhoram o QoE dos passageiros, desde que as condições da rede sejam aproximadamente constantes durante um certo período.Mestrado em Engenharia de Computadores e Telemátic

Dynamic Workload Balancing and Scheduling in Hadoop Mapreduce with Software Defined Networking

Hadoop offers a platform to process big data. Hadoop Distributed File System (HDFS) and MapReduce are two components of Hadoop. Hadoop adopts HDFS which is a distributed file system for storing data and MapReduce for processing this data for users. Hadoop stores data based on space utilization of datanodes, without considering the processing capability and busy level during the running time of each datanode. Furthermore datanodes may be not homogeneous as Hadoop may run in a heterogeneous environment. For these reasons, workload imbalances will appear and result in poor performance. We propose a dynamic algorithm that considers space availability, processing capability and busy level of datanodes to ensure workload balance between different racks. Our results show that the execution time of map tasks moved will be reduced by more than 50%. Furthermore, we propose a method in which Hadoop runs on a Software Defined Network in order to further improve the performance by allowing fast and adaptable data transfers between racks. By installing OpenFlow switches to replace classical switches on a Hadoop cluster, we can modify the topology of the network between racks in order to enlarge the bandwidth if large amounts of data need to be transferred from one rack to another. Our results show that the execution time of map tasks moved is significantly reduced by about 50% when employing our proposed Hadoop cluster Bandwidth Routing algorithm. Apache YARN is the second generation of MapReduce. YARN has three built-in schedulers: the FIFO, Fair and Capacity Scheduler. Though these schedulers provide users different methods to allocate resources of a Hadoop cluster to execute their MapReduce jobs, they do not guarantee that their jobs will be executed within a specific deadline. We propose a deadline constraint scheduler algorithm for Hadoop. This algorithm uses a statistical approach to measure the performance of datanodes and based on this information the proposed algorithm creates several check points to monitor the progress of a job. Based on the progress of jobs at every checkpoint the proposed scheduler will assign them to different job queues. These queues will have different priorities and the proportion of resources used by these queues will depend on their priority. The results of our experiments show that the proposed scheduler ensures that jobs will be completed within a given deadline whereas the native schedulers cannot guarantee this. Moreover, the average job execution time in the proposed scheduler is 56% and 15% less when compared to the Fair and EDF schedulers respectively.Computer Scienc

Software-Defined Networking: A Comprehensive Survey

peer reviewedThe Internet has led to the creation of a digital society, where (almost) everything is connected and is accessible from anywhere. However, despite their widespread adoption, traditional IP networks are complex and very hard to manage. It is both difficult to configure the network according to predefined policies, and to reconfigure it to respond to faults, load, and changes. To make matters even more difficult, current networks are also vertically integrated: the control and data planes are bundled together. Software-defined networking (SDN) is an emerging paradigm that promises to change this state of affairs, by breaking vertical integration, separating the network's control logic from the underlying routers and switches, promoting (logical) centralization of network control, and introducing the ability to program the network. The separation of concerns, introduced between the definition of network policies, their implementation in switching hardware, and the forwarding of traffic, is key to the desired flexibility: by breaking the network control problem into tractable pieces, SDN makes it easier to create and introduce new abstractions in networking, simplifying network management and facilitating network evolution. In this paper, we present a comprehensive survey on SDN. We start by introducing the motivation for SDN, explain its main concepts and how it differs from traditional networking, its roots, and the standardization activities regarding this novel paradigm. Next, we present the key building blocks of an SDN infrastructure using a bottom-up, layered approach. We provide an in-depth analysis of the hardware infrastructure, southbound and northbound application programming interfaces (APIs), network virtualization layers, network operating systems (SDN controllers), network programming languages, and network applications. We also look at cross-layer problems such as debugging and troubleshooting. In an effort to anticipate the future evolution of this - ew paradigm, we discuss the main ongoing research efforts and challenges of SDN. In particular, we address the design of switches and control platforms—with a focus on aspects such as resiliency, scalability, performance, security, and dependability—as well as new opportunities for carrier transport networks and cloud providers. Last but not least, we analyze the position of SDN as a key enabler of a software-defined environment