Contribuições para a análise e simulação de redes ópticas: aspectos de Engenharia de Tráfego, restauração dinâmica e conversão de comprimentos de onda / Contributions for the analysis and simulation of optical networks: aspects of traffic engineering, dynamic restoration and conversion of wavelenghts

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

The Wavelength Division Multiplexing (WDM) technology as well as both the introduction of all optical OXCs (Optical Cross Connect) and OADMs (Optical Add/Drop Multiplexer) may provide the optical network with the networking function, i.e, the capacity to manipulate wavelengths in order to implement their routing. This possibility implies a new type of relationship between applications and the physical layer. The likely candidate to establish such relationships is GMPLS architecture. Efficient solutions to both the problems of allocating resources and traffic routing become an enhanced requirement in the design, expansion and management of optical networking. The present study focus at the relationship between functionalities such as traffic grooming, network fairness improvement, protection/restoring mechanisms and wavelength conversion in heterogeneous optical networks, evaluating the metrics of blocking probability, probability of traffic blocked and fairness. These functionalities are separately treated in literature. With this goal in mind, a two-layer representation is used in order to model the network: the physical and virtual layers, respectively. Two policies on traffic grooming are set up, as follows: MrTV (route minimizing on virtual topology) and MrTF (route minimizing on physical topology). The performance of such policies is analyzed regarding the percentage of blocked traffic. Next, a mechanism for call admission control (CAC) is implemented and its influence in terms of fairness and blocking probability is discussed. The simulations of optical networks such as NSFnet and the Italian National Network are carried out through a graph based in Zhu and Mukherjee [28]. As a result, MrTF policy presents a smaller percentage of blocked traffic than the MrTV for the simulated networks and the rolling window mechanism has allowed the optimization of the call admission control (CAC) mechanism. The usefulness of placing wavelength converters in a few networks nodes (spare conversion) is studied and an analysis on the blocking probability is presented. Next, the network fairness for this distribution of wavelength converters is presented. Finally, techniques for restoring both physical and virtual layers are also implemented and an analysis regarding their influence on the blocking probability and the network fairness is carried out.

ASSUNTO(S)

tráfego dinâmico agregação de tráfego roteamento routing grooming traffic wdm optical network alocação de recursos gmpls resource allocation imparcialidade dynamic traffic controle de admissão de conexões rede óptica wdm gmpls fairness restoring and optimization connection admission control restauração e otimização

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