For an Internet connection, one has to plug a device called between the ISP (Internet Service Provider) and device. Some Routers are available with USB option, where you can attach an external Hard Disk that allows files to be stored and retrieved across a computer network. Asus one of the largest IT hardware manufacturer providing these kind of devices by which you can connect to the internet and make your external hard disk available on the Internet as FTP server just by configuring AiDisk utility from the router’s administrator panel.
Source: https://thehackernews.com/2014/01/asus-wireless-router-leaves-usb-storage.html