Self-similar LAN/WAN traffic issues on high-speed QoS networks.

• Main Author: Anibal Dario Angulo Miranda
• Other Authors: Alessandro Anzaloni
• Format: Others
• Language: English
• Published: Instituto Tecnológico de Aeronáutica 2004
• Subjects: Tráfego auto-similar (Telecomunicações); Redes de comunicação; Análise estatística; Processos estocásticos; Garantia da qualidade; Programação matemática; Algoritmos; Teoria de filas; Telecomunicações; Modo de transferência assíncrono; Engenharia eletrônica; Computação
• Online Access: http://www.bd.bibl.ita.br/tde_busca/arquivo.php?codArquivo=123

During the last decade, the enormous commercial explosion of the Internet has brought up the exhaustive use of Public Telephone Switched Network (PTSN) communication lines by computers (end-users) from all over the world. As a direct consequence of this explosion, a brand new research field, inside the context of the so-called Queuing Theory, has emerged. In fact, the actual dynamics of LAN/WAN data packets has revealed, statistically speaking, a very interesting hidden behavior. These traffic flows possess an intrinsical scale invariance property; this means that, whatever the observational time scale is, their statistical properties remains almost the same. This constitutes a core property of fractal processes. It is, by far, in sharp contrast with classical traffic assumptions, like those models based on Markovian rules. All measurements and results presented here were based on real LAN/WAN traffic traces gathered at ITA's gateway. Basically, this Thesis covers from how to identify the problem up to how to control it. Many statistical methods, to infer an unbiased and well-defined Hurst parameter are developed. Beside this, a mathematical formulism, to be used in our simulation studies, is presented. An open-loop Call Admission Control (CAC) scheme, based on that mathematical formulism is proposed. This CAC algorithm is confronted against the current ATM Forum's ABR service CAC close-loop algorithm. Furthermore, a pure stochastic simulation analysis of the proposed open-loop CAC algorithm, enhancing its advantages and drawbacks, is shown. From these simulation studies some new results have emerged. Finally, we can stand the following: the Internet explosion gave us the exceptional chance to have a real fractal queueing theory, such an issue has never seen before, however, under certain networking conditions, it can be reduced to the well-known classical Markovian-based queuing theory.