He typed the command into the terminal: xmodem -k factory_rescue.bin

The most reliable way to obtain software for this ONT (Optical Network Terminal) is through the Huawei Enterprise Support Portal , which provides: Official Datasheets and Quick Start guides. Troubleshooting Guides for specific issues like slow Wi-Fi or IPTV freezing. Software Repository

Most top firmwares come with Telnet enabled on port 23. Use a client like PuTTY. Then run: