1. A method of constructing an end-to-end routing path across multiple packet switched domains supporting one or more connection oriented technologies, the method comprising the steps of: generating a domains topology identifying all possible domains from said multiple packet switched domains, the border elements of those domains, and inter-domain links among those domains; receiving a request for computation of a path from a source entity in a source domain to a destination entity in a destination domain; removing from the domains topology all domains and inter-domain links that are unlikely to be traversed in the requested path; computing candidate intra-domain paths for each domain remaining after the removal step, wherein each candidate intra-domain path is capable of inclusion in the requested path from the source entity to the destination entity; mapping each candidate intra-domain path to a corresponding domain-specific logical link defined by its two ends, one end being a border element and the other being another border element or the source or destination entity; determining attributes for each logical link; determining attributes of the inter-domain links remaining after the removal step; generating a virtual network topology by combining the logical links and their associated attributes with the remaining inter-domain links and their associated attributes; and determining a best end-to-end route by analyzing said virtual network topology.