This is the multiplexer-side equivalent of gnGenXActNumOfInterfaceOnClass1, reporting the actual number of interfaces classified into class 1 as seen from the MUX board's status view rather than the general element view. It matters when troubleshooting a discrepancy between the general and MUX-specific interface counts, which could indicate a synchronization problem between the MUX board and the main manager module, the kind of issue gnGenXSyncIdcDataBase's sync operation might be used to resolve. An admin seeing this MUX-reported class 1 count differ from the general element's class 1 count would treat that mismatch as a signal to trigger a database resync between the boards.