Extensões na arquitetura SDN para o provisionamento de QoS através do monitoramento e uso de múltiplos caminhos

The substantial increase in the number of applications offered through the computer networks, as well as in the volume of traffic forwarded through the network, have hampered to assure adequate service level to users. The Quality of Service (QoS) offer, honoring specified parameters in Service Level Agreements (SLA), established between the service providers and their clients, composes a traditional and extensive computer networks’ research area. Several schemes proposals for the provision of QoS were presented in the last three decades, but the acting scope of these proposals is always limited due to some factors, including the limited development of the network hardware and software, generally belonging to a single manufacturer. The advent of Software Defined Networking (SDN), along with the maturation of its main materialization, the OpenFlow protocol, allowed the decoupling between network hardware and software, through an architecture which provides a control plane and a data plane. This eases the computer networks scenario, allowing that new abstractions are applied in the hardware composing the data plane, through the development of new software pieces which are executed in the control plane. This dissertation investigates the QoS offer through the use and extension of the SDN architecture. Based on the proposal of two new modules, one to perform the data plane monitoring, SDNMon, and the second, MP-ROUTING, developed to determine the use of multiple paths in the forwarding of data referring to a flow, we demonstrated in this work that some QoS metrics specified in the SLAs, such as bandwidth, can be honored. Both modules were implemented and evaluated through a prototype. The evaluation results referring to several aspects of both proposed modules are presented in this dissertation, showing the obtained accuracy of the monitoring module SDNMon and the QoS gains due to the utilization of multiple paths defined by the MP-Routing, when forwarding data flow through the SDN.

A escola do urbano no campo do município de Catalão/GO : ensino de geografia nas especificidades do lugar

This study makes an approach to the Morro Agudo Community (Cisterna) located in Catalão city(GO) rural area where stands the Maria Bárbara Sucena Municipal School. This school center is a result of getting together several small and isolated schools, which worked, scattered in many rural communities in the region. After this centralization in a single school, many students had to move along inconvenient distance to get their classes. Morro Agudo Community (Cisterna) was outstanding at garlic cultivation throughout the 1990`s when eventually this activity came to a decline. The region is constituted by properties of small tract of land. The landowners come from a Portuguese background and there are, in addit ion, migrant workers from the northeast region of Brazil. These northeasterners work for these local landowners, and that brings an additional meaning to the social relations in the region and to the rural schooling. The social and cultural diversity of the region has a feedback at the school arising tensions in many ways. In the teaching and learning process the school deals with this diversity, combined with rules and goals that, in the end, delivers a geography teaching not able to value the local knowledge accumulated in the region by its own inhabitants. New methodological approaches to rural school communities emerged out of the analysis of these unmet expectations. Furthermore, this study takes into consideration some “residues”, that means not all events are fit into programs; there are unintended consequences in an open process. All these are object of deep review in this doctoral dissertation. In this community, an analysis of the public policies implemented by Federal and municipal governments to rural schools communities in Brazil was conducted. The way in which public policies toward rural communities are implemented at the schools was reviewed; the goals they pursue and the role played by textbooks are also object of analysis. This study questions the relevance of this tools, mainly if they meet the real needs of the local people. The social representations of teachers and students are considered carefully based on their everyday lives and experiences.