1:3 cross-connection mode needs to add two CXCS cross-connection boards, resulting in fewer supported service slots than 1:1 cross-connection mode by two 11U large slots. Therefore, in 1:3 mode, the maximum capacity of the OptiXtrans E9624 subrack The crossover capacity is smaller than in 1:1 mode.

The wavelength division system is configured with the 1st to 20th waves, and uses the NS4 single board. During the commissioning, the optical spectrum analyzer is used to test the M40 output port. It is found that the optical power of the 20th wave is significantly lower than the other 19 waves. Which of the following are the possible reasons? (Multiple choice)

The WDM system mainly adopts the DCM compensation method for the compensation of the chromatic dispersion. In the following description about the DCM dispersion compensation, which one is wrong?

The Raman amplifier is a distributed amplifier, and its amplifying medium is a transmission fiber, which is generally placed at the receiving end and is called a forward Raman amplifier.

When 172.17.15.0/24 uses 4 extra bits for subnetting, which of the following addresses are legal subnet addresses? (Multiple choice)