A network planning tool and method for configuring a connection-oriented packet network over a WDM optical network without an optical control layer, such as a SONET/SDH layer. The optical network includes a plurality of optical fibers interconnected through nodes and the connection-oriented packet network, such an Ethernet network, MPLS network, or pseudowire network, includes two or more terminal devices. The method and tool function by building an association between the components of the physical layer, such as the optical fiber, and their geographic location or path. The connection-oriented packet network is configured by building multi-link trunks (MLTs) between terminal devices, where the MLTs are built by aggregating lightpaths that traverse distinctive geographic paths. The MLTs are planned and configured through aggregating lightpaths that traverse incongruent sets of photonic elements. A predetermined target for resiliency to physical failure events may determine the degree of congruence allowed between the sets of photonic elements associated with lightpaths in the same MLT.