Physical SDN The Final Frontier of Software-Defined Networking ( SDN ) at the Fiber Optic Physical Layer: Extending Automation to the Physical Network Layer for Rapid Reconfiguration, Reprovisioning and Retasking of Data Centers, 5G Mobile Backhaul and Carrier Networks. Telescent's G4 Network Topology Manager (G4 NTM) automated fiber optic patch-panel and cross-connect implements physical layer automation and virtualization within a wide range of network applications. Fiber optic connections between network devices are automatically reconfigured, monitored and mapped by this unique system. The G4 NTM provides scalability from 48 to 1008 duplex any-to-any connections (or 2016 simplex any-to-any connections), provides single mode & multimode connectivity, and provides industry leading low insertion loss all while not degrading data transmission as data rates increase past 100G.