This post explains the procedure to obtain such privileges from a Youhua PT926G fiber optic modem, without disassembling the device or using serial port converters. Super Admin users on Web UI (telecomadmin) Telnet's root user access FTP access FYI I obtained the device from China Telecom, Guangdong Shenzhen. Log on as Super Admin If you directly access the modem's IP ( http://192.168.1,1 ), you will see such a login page to the modem: Here you can log in with account name useradmin and the password labeled on the back of the modem, but there's not much you can do once logged in. The only useful thing seems to be Wi-Fi setting. But a Nmap scan reveals much more: $ nmap -v 192.168.1....