Showing papers by "Alessio Botta published in 2013"

D-ITG: Distributed Internet Traffic Generator

Abstract: In this paper we present our traffic generation platform, named D-ITG (Distributed Internet Traffic Generator). Its features are first described. We believe that some capabilities are in fact innovative, since no other traffic generator offers them. Then, we describe the original architecture of D-ITG, which allows our traffic generator to achieve high performance. We hint at a comparison with other traffic generators and conclude with the ongoing work to add new features.

Efficient Storage and Processing of High-Volume Network Monitoring Data

Abstract: Monitoring modern networks involves storing and transferring huge amounts of data. To cope with this problem, in this paper we propose a technique that allows to transform the measurement data in a representation format meeting two main objectives at the same time. Firstly, it allows to perform a number of operations directly on the transformed data with a controlled loss of accuracy, thanks to the mathematical framework it is based on. Secondly, the new representation has a small memory footprint, allowing to reduce the space needed for data storage and the time needed for data transfer. To validate our technique, we perform an analysis of its performance in terms of accuracy and memory footprint. The results show that the transformed data closely approximates the original data (within 5% relative error) while achieving a compression ratio of 20%; storage footprint can also be gradually reduced towards the one of the state-of-the-art compression tools, such as bzip2, if higher approximation is allowed. Finally, a sensibility analysis show that technique allows to trade-off the accuracy on different input fields so to accommodate for specific application needs, while a scalability analysis indicates that the technique scales with input size spanning up to three orders of magnitude.

Active techniques for available bandwidth estimation: comparison and application

Abstract: There are various parameters for analyzing the quality of network communication links and paths, one attracting particular attention is available bandwidth. In this chapter we describe a platform for the available bandwidth estimation, a comparison of different tools for the estimation of this parameter, and an application of such estimation in a real-world application. In details, we describe a novel platform called UANM, capable of properly choosing, configuring, and using different available bandwidth tools and techniques in an autonomic fashion. Moreover, thanks to UANM, we show the results of a comparison of the performance of several tools in terms of accuracy, probing time and intrusiveness. Finally, we show a practical example of the use of the available bandwidth measurement: we describe an approach for server selection and admission control in a content distribution network based on the available bandwidth estimation.

New generation satellite broadband Internet services: Should ADSL and 3G worry?

Abstract: In the context of Internet access technologies, satellite networks have traditionally been considered for specific purposes or as a backup technology for users not reached by traditional access networks, such as 3G, cable or ADSL. In recent years, however, new satellite technologies have been introduced in the market, reopening the debate on the possibilities of having high-performance satellite access networks. In this paper, we describe the testbed we set up - in collaboration with one of the main satellite operators in Europe - and the experiments we performed to evaluate and analyze the performance of both Tooway and Tooway on KA-SAT (or KA-SAT for short), two satellite broadband Internet access services. Also, we build a simulator to study the behavior of the traffic shaping mechanism used by the satellite operator. In terms of performance, our results show how new generation Internet satellite services are a promising way to provide broadband Internet connection to users. In terms of traffic shaping, our results shed light on the mechanisms employed by the operator for shaping user traffic and the possibilities left for the users.

An experimental characterization of the internal generation cycle of an open-source software traffic generator

Abstract: The paper is the first step towards the goal of evaluating the measurement uncertainty of the inter-departure times (IDT) provided by software traffic generator. The paper is focused on the experimental characterization of the internal generation cycle of a well-known, open source generator, namely D-ITG, for different systems, and under the best possible conditions, i.e. with the minimum system loads. The resulting performance may be seen as the ideal limit the generator can tend to. The extended abstract presents the rationale for the activity, the underlying methodology and some initial tests that highlight the relevance of the clock resolution in the accuracy of IDT.