A method of routing data streams in a meshed system, wherein it implements multitopology routers, each provided with an intelligent module, and in that it comprises, for each router, in combination, at least the following steps: ➢ accounting the resource requirements to keep to the quantitative and qualitative flow objectives of the accepted streams, the accounting being organized according to the operational importance of the streams, ➢ propagating from router to router of the expressed requirements using a switched signaling in a topology and a mapping in each router between topology and operational importance in order to allow for the accounting of the accepted needs, ➢ at the level of an intelligent module using the accounting of the accepted needs to generate a metric of links for each of the topologies, ➢ at the level of each multitopology router maintaining routing data, with, in particular, the link metrics calculated dynamically by each intelligent module and determines a switching table for each topology, ➢ each router is adapted to allow the propagation of the data streams according to the switching table associated with the topology, a topology that is designated by the packet header fields; hierarchically organizing the topologies or routing plans, managed by the network of multitopology routers, a topology being defined by independent metrics and giving rise to an optimum route calculation, ➢ assigning resources to each link, said resources being able to be used immaterially by the data packet streams, independently of the topology to which they belong, ➢ determining the metrics of a topology of level n-1, taking into account the resources reserved by the streams drove on topologies of operational importance strictly higher of level n or of a level higher than n, ➢ maintaining separate routing data for each topology and switching tables that are also separate for each topology, ➢ updating on each router the routing data by using, between the routers, an all-topology routing protocol and metrics specific to each topology. ➢ accounting the resource requirements to keep to the quantitative and qualitative flow objectives of the accepted streams, the accounting being organized according to the operational importance of the streams, ➢ propagating from router to router of the expressed requirements using a switched signaling in a topology and a mapping in each router between topology and operational importance in order to allow for the accounting of the accepted needs, ➢ at the level of an intelligent module using the accounting of the accepted needs to generate a metric of links for each of the topologies, ➢ at the level of each multitopology router maintaining routing data, with, in particular, the link metrics calculated dynamically by each intelligent module and determines a switching table for each topology, ➢ each router is adapted to allow the propagation of the data streams according to the switching table associated with the topology, a topology that is designated by the packet header fields; hierarchically organizing the topologies or routing plans, managed by the network of multitopology routers, a topology being defined by independent metrics and giving rise to an optimum route calculation, ➢ assigning resources to each link, said resources being able to be used immaterially by the data packet streams, independently of the topology to which they belong, ➢ determining the metrics of a topology of level n-1, taking into account the resources reserved by the streams drove on topologies of operational importance strictly higher of level n or of a level higher than n, ➢ maintaining separate routing data for each topology and switching tables that are also separate for each topology, ➢ updating on each router the routing data by using, between the routers, an all-topology routing protocol and metrics specific to each topology.