OTN (Optical Transport Network) systems smoothly handle ever-increasing bandwidth demands for data services and for mobile back-haul, front-haul, and Data Center interconnection, by integrating the functionality of transport, multiplexing, switching, protection, and management of customer traffic in a single box. Compact OTN systems easily meet the high bandwidth demands of public and private clouds as well as software-defined networks. For 4G/5G applications, enabling carriers to save fiber resources when deploying mobile front-haul infrastructure.