Algorithmes de routage : de la réduction des coûts de communication à la dynamique. (Routing algorithms : from communication cost reduction to network dynamics)

Routing algorithms, from communication cost reduction to network dynamics In order to respond to routing queries, the entities of the network, nammed routers, require to have a knowledge concerning the topology of the network, this knowledge is called routing table. The network is modeled by a graph in which nodes represent routers and edges represent communication links between nodes. This thesis focuses on routing tables computation in a distributed model. In this model, computations are done by a set of process placed on nodes. Every process has for objective to compute the routing table of the node on which he is placed. To perform this computation, processes have to communicate with each other. In large scale network, in the case of a distributed computation, maintaining routing tables up to date can be costly in terms of communication. This thesis focuses mainly on the problem of communication cost reduction. One of the solution we propose is to reduce routing tables size which allow to reduce communication cost. In the centralised model this strategy is well known under the name of compact routing. This thesis presents in particular a distributed compact routing algorithm that allows to reduce significantly the communication costs in networks like Internet, i.e. the autonomous systems network and others networks that present scale-free properties. This thesis also contains an experimental study of several distributed compact routing algorithms. Finally, some problems linked to network dynamicity are addressed. More precisely, the problem of network deconnexion during a shortest path tree computation with auto-stabilisation guaranties, together with a study of the impact of several edges or nodes deletion on the state of the routing tables .