It is typically deployed over Dense Wavelength Division Multiplexing (DWDM) but can also operate as a standalone digital transport layer. As a standardized Layer-1 digital transport technology, OTN unifies different types of services, legacy and modern, into a single, robust. At the top of our diagram, the ODU (Optical Data Unit) layer serves as the digital transport layer of OTN. The access layer serves as the entry point for end-users and devices, managing connectivity and initial data transmission. Moving upward, the. An optical transport network (OTN) is a digital wrapper that encapsulates frames of data, to allow multiple data sources to be sent on the same channel.
