This read-write setting configures the operating mode, such as inactive, dedicated, answer, or call-backup, for the WAN link on port 3, provided that port is configured with the PVCR protocol, during this schedule period, following the same pattern as schedulePort1 and schedulePort2 but for the unit's third such port. Since this entry has no distinct description text, its behavior is inferred from the identical enumeration and naming pattern shared across the schedulePort series. For example, setting this object to call-backup(4) during this period configures port 3 to use call-backup behavior only for the duration this schedule period is active.