Can the RAU2 board be replaced with the OBU2 board

Dear friend!
The RAU2 board is equipped with a backward Raman unit and an erbium-doped fiber amplifier (EDFA) unit. When the OBU2 board is used at the receiving end, the RAU2 board can be used to replace the OBU2 board. When the RAU2 board is used at the transmit end, the RAU2 board cannot be used to replace the OBU2 board.
Thank you!

hi dear ,
RAU2 board is much better than OBU2 in 2 main points:-
1- in term of gain the RAU2 gives (30 to 41) in G.652 fibers while OBU2 gives only 23
2- in term of Noise Figure RAU2 doesn't exceed < 1.5 (in case of 30 dB gain) while OBU2 cause ≤ 7.0.
I think you should take these values in consideration because they have big affect on OSNR and power budget before you change the board .