One aspect of the disclosure provides a method for allocating traffic in a telecommunications network. The telecommunications network comprises a plurality of nodes, with pairs of nodes being connected by respective links. A plurality of demands for connectivity between respective first nodes and respective second nodes are allocated to the telecommunications network, with traffic for each demand being directed via a respective plurality of paths between the respective first and second nodes in accordance with respective weights assigned to each path. The method comprises: determining a criticality of each link forming a path of the plurality of paths for a demand of the plurality of demands, the criticality of a link varying as a function of a utilization of that link at a non-constant gradient between a minimum value at a first value of the utilization and a maximum value at a second value of the utilization, wherein the second value corresponds to a utilization which is over a capacity of the link: determining a criticality of the path as a function of the criticality of the links forming the path: and determining the weight for allocation of traffic to the path as a function of the criticality of the path.