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. This is where the Optical Transport Network (OTN) plays a critical role. 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. It is an advanced platform built upon the traditional OTN platform, featuring next-generation cross-connect architecture and new lossless technologies and protocols.