Which of the following statements about the MPLS-TPOAM level is correct?

The characteristic of the open DWDM system is that there are no special requirements for the optical interface of the multiplexing terminal, and only these interfaces are required to comply with the optical interface standard recommended by ITU-T. The DWDM system adopts wavelength conversion technology to convert the optical signal of the multiplexed terminal into a specific wavelength, and the optical signal of different terminal equipment is converted into different wavelengths that comply with ITU-T recommendations, and then multiplexed.

Which of the following statements is incorrect about the optical layer interfaces OTM-nm and OTM-nrm of OTN?

The MPLS label has four identification fields, Lable, EXP, S and TTL, with a total of 4 bytes, of which Lable occupies 20 bits. The label value 0-15 is reserved for special purposes, which indicates that the inner payload carried is MPLS-OAM packet. , the label value is which of the following?

Which of the following descriptions about network protection switching test is wrong?