Proxy CC – reserva de banda dinâmica baseada em contexto

Abstract

This dissertation consists of presenting a proposal to the use of the context-aware computing paradigm to availability of computer resources to institutions, in view of the increasing need for efficiency and effectiveness in this area. It is observed that these networks commonly have a variable flow, causing both overloads and underutilization of resources. Seeking to alleviate this problem, the option of creating a context-aware network arises. This research brings the proposal of a context-aware proxy, which allows the adaptation of link resources provided by the organization, aiming to soften the problems of overload and underutilization of the link. In an attempt to solve the overload problem, organizations end up plastering control over links through rules, causing thus other problems such as underutilization, which happens when despite having the resource available, it is not usable, affecting the quality of services and even causing its unavailability. The environment analysis is an important point, allowing to identify contextual evaluation parameters such as the contexts of VoIP, Vconf and Webconf services, among others. After defining the context parameters it was possible to reach the proposal of inserting a proxy server between the firewall and the switches, in order to guarantee the capture of the current context information to compare with the defined in the application. Two tests of 30 days each were performed to evaluate operation and performance of the tool, using a traffic generator. The comparison between the results of the first and the second tests showed a reduction of flow variations in the test with the context module active, thus making the link flux more uniform. In the test with context module disabled it was possible to notice that, even without the use of all services that have reserved band, the reserve happened, causing an underutilization of approximately 25% of the resources. Another important point is the case of limitation when the user reaches 10% of the band, causing the traffic speed limitations for that user, creating another case of underutilization with even greater impact. The results favorable to the creation of ProxyCC's proposal for achieving a significant improvement, allowing a dynamic delivery of the resource and maintaining the flow in a constant way without great variations. The proposal met the objective of reducing the problems of link overloading and underutilization, making the resources availability flexible, allowing the adaptation to the current context.