1. In a physical network having physical transmission and switching resources, a method for partitioning the physical transmission resources among logical networks, the method comprising the steps of: establishing a set of logical networks on top of the physical network, wherein the logical networks include nodes and logical links, and the logical links are used by routes interconnecting the nodes of node pairs in the logical networks; determining logical link capacities of the logical links; and allocating the physical transmission resources among the logical links of the logical networks according to determined logical link capacities; wherein the step of determining logical link capacities is performed under the constraint that the route blocking probability of each route in each logical network is required to be less than or equal to a maximum allowed blocking probability for each individual route, and performed under a distribution, for each route, of the route blocking probability evenly among the logical links used by the individual route.