A network provisioning system for establishing a path between two networks is disclosed wherein a common network device between those networks is modeled as a link between a first network element in one network and a second network element in a second network. A network routing graph is created by an inventory subsystem in a routing manager by inventorying the physical network elements and links in the network. The inventory subsystem then models those elements/links as a plurality of nodes and links between the nodes. At least one common network device, such as a digital cross connect connecting the two networks, is modeled as a link instead of a node. A routing engine then uses the network routing graph, including the link modeled from the common network device, to provision a path between the networks.
