Experimentación con software de ingeniería de tráfico.

Abstract

Wide area networks have experienced a continuous increase of users and traffic. Due to its cost, networks cannot be continuously upgraded. Therefore, operators should do a better use of network resources, diverting traffic to less congested links. Accordingly, it is necessary to investigate and implement new routing algorithms, in order to better optimize resources and to accommodate a greater amount of traffic on the network. The study of new routing algorithms involves performing tests on an experimental scenario to check to which extent improvements are experienced. This requires either testing on the actual network, with the associated technical and safety risks, or the use of simulators. In our case we decided to use the program Totem, a free, open source software. In order to experiment with new traffic engineering algorithms, in the first part of the work we have studied the Totem program to understand how it works and identify the algorithms that we can simulate. Here we performed a comprehensive study about the performance of every algorithm that we can simulate, in order to understand the results. In the next part of the work we have carefully analyzed the topologies of two operational networks, RedIRIS and GÉANT, with the aim of using them for simulation. From these two wide area networks, by using the tools of looking glass available, we can obtain the necessary data. Then, we performed the calculation of a GÉANT's traffic matrix using the tomogravity method to understand its operation, and after that we have obtained all GÉANT's traffic matrix corresponding to one week, extracted (by means of scripts) from previous degree theses. Finally we analyze the scenarios' structure used to simulate each routing algorithm and perform tests using the topology GÉANT and the extracted tomogravity traffic matrix to evaluate the performance of each algorithm metrics, representing the results graphically. The document ends with conclusions and future lines of study for these investigations.

Las redes de conmutación de paquetes han experimentado un aumento continuo tanto de usuarios cómo de tráfico. Debido a su coste, las redes no pueden ampliarse constantemente, sino que deben aprovecharse mejor los recursos de la red, desviando el tráfico por enlaces menos congestionados. Por esto es necesario el estudio e implantación de nuevos algoritmos de ingeniería de tráfico, con el objetivo de optimizar mejor los recursos y poder alojar una mayor cantidad de tráfico en la misma red. El estudio de nuevos algoritmos implica la realización de pruebas en un medio experimental, para comprobar si ofrecen mejoras respecto a otros. Para ello es necesario o bien realizar pruebas en la misma red, con las dificultades técnicas y de seguridad que esto comporta, o bien realizar simulaciones de red con alguno de los programas existentes. En nuestro caso hemos decidido utilizar el programa Totem ya que es un software libre de código abierto