In certain embodiments, a communication (comm) network has interconnected comm systems and a mapping engine, each comm system having one or more Layer 1 (L1) components physically connected to one or more Layer 2 (L2) components, wherein components are physically connected to L1 components of different comm systems. Logical connections between the L2 components of the different comm systems are determined using a link-layer discovery process (LLDP), and physical connections between the L1 and L2 components of each comm system are determined using LLDP snooping. The mapping engine queries the L2 components for LLDP results and the L1 components for LLDP snooping results and generates end-to-end mappings for circuits between the L2 components of the different comm systems, where the end-to-end mappings are represented in a circuit inventory database that can be accessed to avoid system outages when the network is modified.