You can use FTP for file upload when your catalog feed file is over 4MB, but under 1GB. If your feed file is larger than 1GB, split it into multiple files and create corresponding catalogs.
The recommended FTP upload mechanism is via an FTP program. It is however possible to do so via the command line or custom scripts (such as Python’s ftplib.FTP module). The FileZilla FTP client is recommended for all platforms.
Use the following settings for file transfer with your FTP client: