There is provided a traffic placement method in a communications network, the communications network comprising a plurality of nodes, the nodes being connected to one another by links, the method comprising selecting a (possibly non-strict) subset from a given set of traffic flow demands and calculating a plurality of paths for the selected demands under consideration of a set of constraints using an algorithm hybridization combining backtrack search with local consistency techniques (BT+CS) and guiding search by the use of one or more probe generators, that is, search techniques that solve a routing sub-problem or an arbitrary relaxation of the traffic placement problem. By using a hybrid algorithm that integrates other solvers (search techniques) into BT+CS through the use of probe generators, a more powerful search strategy can be achieved compared to BT+CS or the individual search techniques.