Dear friend!
MSTP still uses the SDH technology for transmission on the line. Therefore, the maximum transmission bandwidth is 40 Gbit/s.
Currently, the OTN has been successfully tested and verified for single-wavelength 1.6T, and the single-wavelength 800G has been put into commercial use. For an 80-wavelength system, the transmission rate on a pair of optical fibers is 64 Tbit/s.
Thank you!