2.5G OTU board is an optical transform for optical fiber links. It can regenerate 3R signals for 32Mbit/s~2.488Gbit/s services with arbitrary rate protocols, and can be converted into CWDM or DWDM standard wavelength optical signal. It can be used in optical communication systems such as PDH/SDH/POS/SONET/SAN/ETHERNET with CWDM or DWDM multiplexer/demultiplexer to realize wavelength division multiplexing transmission. It provides a high-quality solution for solving transmission lines with insufficient fiber resources and high fiber line loss.