DWDM and OTN are two different technologies in the field of optical communication.

DWDM is an optical transmission technology used to simultaneously transmit multiple wavelengths of optical signals in optical fibers, thereby expanding the transmission capacity of optical fibers, increasing network bandwidth, and supporting long-distance transmission.

OTN is a network transmission technology based on DWDM. In addition to optical transmission, it also provides higher-level switching, management, and monitoring functions to achieve reliable, flexible, and efficient optical network transmission.

Function extension:

DWDM mainly focuses on the multiplexing and transmission of optical signals, and does not involve signal exchange, management, and monitoring.

OTN introduces higher-level functions on the basis of DWDM. OTN technology provides multi-level exchange, management, and monitoring functions by packaging data in a fixed format. It can handle data streams of different types and rates, and provide flexible bandwidth allocation, fault recovery, and performance monitoring functions.

Technical application:

DWDM is commonly used to increase the transmission capacity and bandwidth of fiber optic networks, enabling long-distance optical transmission.

OTN is widely used in the construction and management of optical networks, providing flexible bandwidth allocation, fault recovery, performance monitoring, and other functions to meet the transmission needs of different types and rates of data streams.

In summary, DWDM is a technology used to improve fiber optic transmission capacity and bandwidth, while OTN is a network transmission technology based on DWDM, with more switching, management, and monitoring functions, used to build reliable, flexible, and efficient optical network transmission systems.