Mécanismes d'agrégation multicast dans un MAN optique avec support de QoS

The explosive growth of the Internet Protocol (IP)-based traffic has accelerated the emergence of wavelength division multiplexing (WDM) technology. In order to provide a simple transport platform of IP traffic over WDM structure, optical packet switching (OPS), based on fixed-length packets and synchronous node operation, is regarded as a long term issue especially for metropolitan area networks (MANs) where the synchronization is easy to handle and relatively simple to maintain. In this context, this thesis presents a novel approach for efficiently supporting IP traffic with several quality of service (QoS) requirements into a synchronous WDM MAN layer. The claimed efficiency is achieved by aggregating IP packets regard-less of their final destinations which yields a multicast optical packet. To support QoS, a timer mechanism is used and a class-based scheme at the edge of optical network is adopted. Several analytical models have been developed to quantify the performance of different versions of the aggregation approach. The different versions correspond to different timer mechanisms and to the permission or the ban of IP packet segmentation by the aggregation process. This is because IP packets have variable size while optical packet is of fixed size. The length variability of IP traffic is included in the analytical models which represents an essential contribution of this thesis. We next investigate the impact of multicast on WDM slotted ring MANs. In particular we focus on two families of MANs. The first family enables destination stripping, while in the second one, ring nodes contain passive components and the stripping is attributed to the hub which separates two different sets of wave-length channels, one for transmission and one for reception. The capacity (maximum throughput) of each network is evaluated by means of an analytical model. The access delay is also investigated by using an approximate approach in the case of destination stripping and an exact approach in the case of hub stripping. Further-more, the impact of the optical packet format on the performance is depicted. We show the attractiveness of the multicast aggregation in MANs through a comparative study with the performance of unicast aggregation and no aggregation approaches therein. Multicast aggregation increases bandwidth efficiency due to the filling ratio improvement exhibited in optical packets. Furthermore, hub stripping networks match very well the multicast nature of the generated optical packets without the addition of any complexity in the node architecture. However, a small overhead complexity is added in the case of destination stripping networks. Note that all approximative analytical models have been validated by using extensive simulations, where two traffic profiles were investigated: Poisson and Self-Similar.EVRY-BU (912282101) / SudocEVRY-INT (912282302) / SudocSudocFranceF