Label switching, which in IP networks is exemplified by MPLS and its extensions MPLambdaS and GMPLS, appears as one of the best alternatives to offer a reliable and flexible control plane for WDM networks, since it allows the integration of the IP Protocol with WDM technology, when lambdas are associated with labels, implements powerful traffic-engineering mechanisms, and provides several alternative schemes for fault-tolerance, as well as support for quality of service (QoS). However, almost all the definitions and standardizations for MPLS are restricted to unicast communication, leaving support for multicast communication for future work. In the specific case of the triggering problem for LSPs (Label Switched Paths), there is still no consensus about the best strategy for multicast communication. This paper proposes an algorithm for traffic-driven triggering of LSPs, based on MFCs (Multicast Forwarding Caches), and has the advantage of being a schema which is compatible with several multicast routing protocols. To validate the proposed algorithm we carry out simulation studies using the NS-2 (Network Simulator) simulation platform.

In this paper a novel software is proposed based on querying system logs and correlating the events registered in those logs. The purpose of this approach is to identify the hosts causing violations to predefined security policies in computer networks.

The increasing use and importance that networks have acquired in today’s economics and social context also brought an increase in the number of malicious activities that violate privacy and security policies of institutional networks. There are several approaches that aim to detect such activities, for instance the usage of intrusion detection systems. The goal of this paper is to present an alternative malicious activity detection approach based on querying and correlation of the events registered in system logs. The purpose of this approach is to identify the hosts causing such malicious activities. Experiments carried at the Brazilian National Research and Educational Network’s Point of Presence at State of Pará have showed that this proposal was able to detect the hosts responsible for malicious activities accurately and demanding low computational resources.

We make a comparative analysis of two proposals for setting up a facilities-based metropolitan network to serve the education and research community in the city of Belem do Para in Brazil, using the “do-it-yourself” (DIY) model of building infrastructure, and benefiting around a dozen research and education institutions. The first alternative is to build a fiber optic network, using Gigabit Ethernet technology. The second one uses a metropolitan wireless network, based on the IEEE 802.16 standard, studying the feasibility of the use of this technology in a context with the particular characteristics of the Amazon region. In both cases, we show that the capital cost for each institution is feasible, and that the total cost in the medium term is lower than the recurrent costs of maintaining the traditional model based on telecommunications provider services.

The necessity of wireless networks already has been felt a long time ago in sight of limitations imposed by the wired networks, mainly related to the increasing necessity of flexibility of the current network projects. In association to this necessity, also is observable a crescent demand for data transmissions that supply the current multimedia applications requirements, just as a larger bandwidth and a greater number of users attended on larger distances. In this context, the wireless metropolitan area networks are one solution that allies the flexibility, common in wireless networks, with the possibility of reaching a greater number of users. This paper investigates the Standard 802.16 and analyses its use for Belém-PA.

Esta tese descreve CM-tel, um modelo de componentes para aplicações telemáticas e ubíquas.
CM-tel é neutro em termos de tecnologia, sendo especificado por meio da linguagem UML (Unified
Modeling Language). Componentes CM-tel são capazes de executar em plataformas destinadas tanto
a computadores tradicionais quanto a dispositivos com limitado poder computacional tais como dispositivos móveis. CM-tel define os três tipos de interfaces prescritas pelo Modelo de Referência para
Processamento Distribuído Aberto (RM-ODP), as interfaces operacional, de sinal e de fluxo contínuo.
Interfaces de fluxo contínuo são fundamentais para o desenvolvimento de aplicações telemáticas. A
arquitetura do contêiner CM-tel integra componentes e agentes móveis em um único ambiente computacional. Esta integração permite que aplicações implementem suas funcionalidades combinando
componentes e agentes móveis. Esta tese propõe ainda uma arquitetura para plataformas de software
que suportam o modelo CM-tel. A arquitetura utiliza XSLT (XML Stylesheet Language Transformation) para transformação de modelos e geração de código. Uma plataforma baseada na tecnologia
CORBA (Common Object Request Broker Architecture) e uma aplicação na área de laboratórios virtuais foram implementadas com a finalidade de avaliar o modelo CM-tel

New research perspectives opened up by the combination of IP and WDM technologies present an excellent opportunity for reformulating certain aspects of multicast transmission, bringing them more in line with the needs of future generations of IP internetworking. This paper analyses MIRRORS, which proposes modifications to traditional IP Multicast in order to improve its scalability as a function of the number of simultaneously active groups, as well as making it more appropriate for use in optically switched networks. In this analysis, MIRRORS is compared with other major multicast alternatives, using such parameters as: information state requirements, control overhead, cost of packet forwarding and cost of the multicast distribution tree.

A difusão seletiva e os recentes avanços na tecnologia de transmissão
óptica, mais especificamente na multiplexação por comprimento de onda
(“Wavelength Division Multiplexing-WDM”), aliados à consolidação do IP como
protocolo dominante das redes convergentes, vêm oferecendo novas perspectivas
para as futuras gerações de inter-redes. Este trabalho faz uso da evolução dessas
tecnologias para propor um conjunto de adaptações à difusão seletiva, em especial
ao IP Multicast, denominado MIRROR (“Multicast IP para Redes baseadas em
Rajadas Ópticas Rotuladas”). A proposta MIRROR sugere modificações e
adequações para tornar o IP Multicast menos complexo, mais escalável em
relação ao número de grupos ativos simultaneamente e mais adequado às redes
baseadas em comutação óptica. Basicamente, MIRROR revê a necessidade de
todos os roteadores ao longo da árvore de distribuição multiponto manterem
informações de estado relacionadas a esta, bem como sugere adequações na forma
como os caminhos multiponto são estabelecidos quando se emprega comutação
baseada em rótulos na difusão seletiva. Para avaliar a proposta MIRROR,
investiu-se em duas frentes distintas, uma baseada na análise comparativa entre a
MIRROR e algumas alternativas ao IP Multicast apresentadas na literatura, e
outra baseada no desenvolvimento de um protótipo da proposta no simulador NS
(“Network Simulator”), com o intuito de referendar os resultados da análise
comparativa. Na análise comparativa, confronta-se parâmetros como: requisitos
de informações de estado, custo com informações de controle, custo de
encaminhamento dos pacotes e custo da árvore de multiponto. O desenvolvimento
do protótipo envolveu a criação de uma nova estrutura de nó e a alteração de
módulos já existentes no NS, para tornar possível a simulação de redes comutadas
por rajadas ópticas rotuladas no contexto da difusão seletiva.

New research perspectives opened up by the combination of IP and WDM technologies present an excellent opportunity for reformulating certain aspects of multicast transmission, bringing them more in line with the needs of future generations of IP internetworking. This paper analyses MIRRORS, which proposes modifications to traditional IP Multicast in order to improve its scalability as a function of the number of simultaneously active groups, as well as making it more appropriate for use in optically switched networks. In this analysis, MIRRORS is compared with other major multicast alternatives, using such parameters as: information state requirements, control overhead, cost of packet forwarding and cost of the multicast distribution tree.

New research perspectives opened up by the combination of IP and WDM technologies present an excellent opportunity for reformulating certain aspects of multicast transmission, bringing them more in line with the needs of future generations of IP internetworking. This paper analyses MIRROR, which proposes modifications to traditional IP Multicast in order to improve its scalability as a function of the number of simultaneously active groups, as well as making it more appropriate for use in optically switched networks. In this analysis, MIRROR is compared with other major multicast alternatives, using such parameters as: information state requirements and the costs of control information, packetforwarding and storing the distribution tree topology.