Which of the following subracks does not support the configuration of packet board?

In the non-aggregated OTU processing SDH standard signal scenario, both A and B are WDM stations, and the R_Los alarm is detected on the client side of the OTU of the A station. After the alarm is processed on the WDM side of the OTU, the client side of the downstream B station detects and reports the REM_SF alarm, and the B station transmits the signal to the downstream client device and reports the R_LOS alarm to the client device.

FOADM includes parallel FOAD and serial FOADM, both supporting 40 waves or 80 waves of arbitrary wavelengths.

The OSN 1800V supports the following packet protection features:

Daily equipment maintenance items, excluding: