Introduces the relationship between SDH service alarms and common equipment alarm suppression.

SDH service class and common equipment class alarm suppression is shown in Figure 1.

The alarm above the arrow suppresses the alarm below the arrow. For example, when a signal loss occurs at an optical port on the customer side, the optical port will only report the R_LOS alarm but not the R_LOC, R_LOF, and other alarms.

Figure 1 SDH service class and common equipment class alarm suppression