1. A provisioning system for establishing a path within a network, said network being comprised of network links and network elements, said system comprising: an inventory subsystem for modeling the network as a graph of nodes and links that interconnect the nodes; a routing engine that uses the graph for determining the path between points in the network; and a service activation system for invoking the routing engine to determine the path between the network points and for determining from the determined path and the network model a set of network element cross-connections to establish a virtual connection over said path; wherein the links of said graph represent network links, wherein each node of said graph represents a partial network element, a single network element, or a group of network elements, wherein each partial network element, a single network element, or group of network elements represented by a given node has edge ports, and wherein any combination of edge ports that are associated with a given node and that are capable of being interconnected can be interconnected.