Many people are of the mind set that FTP servers are slowly becoming a thing of the past. I would disagree because of the low cost of hardware, ease of set up, and ease of use. You can’t beat an FTP server up on your network as a central file repository. More here

Now that you already have your Ubuntu Server up and running, adding FTP is actually quite easy. There are numerous FTP servers available, but the one I tend to prefer is vsftpd. Not only is it more secure than many other FTP servers, it’s easy to install and configure, even for anonymous use.