Hello, everyone!
There are several types of reboot with ONT, as following:
#define HW_MLID_DM_REBOOT_NORMAL_STR "ONU reset by the software"
#define HW_MLID_DM_REBOOT_POWER_OFF_STR "ONU reset after being powered on"
#define HW_MLID_DM_REBOOT_SOFT_ABORT_STR "ONU reset unexpectedly"
#define HW_MLID_DM_REBOOT_MONITOR_STR "ONU reset by the monitoring process"
#define HW_MLID_DM_REBOOT_OOM_STR "ONU reset due to memory shortage"
#define HW_MLID_DM_REBOOT_PANIC_STR "ONU reset due to kernel panic"
#define HW_MLID_DM_REBOOT_HIGHTEMP_STR "ONU reset due to high temperature“
Which can be found from the log exported via TR069/U2000/web/telnet

It also can by found from the fault information exported via Web/telnet, by searching for keywords “dlog”

From group: Transport&Access Network
Thanks.