Hello,
Please check the device source.
1. If you purchase an ONT of the formal enterprise version
Administrator (installation and maintenance personnel):
User name: telecomadmin
Password: admintelecom
Common user (terminal user):
User name: root
Password: admin
IP address: 192.168.100.1
2. If you purchase an ONT customized for a formal carrier version
Certain carriers may customize accounts and passwords, which are different from the default accounts and passwords listed in the preceding. For details, contact the corresponding carrier.
3. It's also possible that someone else changed the password.
Restore the device to its factory settings. (This operation will cause loss of the original configuration data. Exercise caution when performing this operation.)
Good luck!
Thanks