Recording video with cams


Hi, I'm looking for create a system of three cameras that have to send continuously video and audio to my Nas installed at about 300Km far.
In my Foscam FI8918W I can send only the screenshots to my Ftp server. Then probably I'll be forced to use a hard disk or a nas into the flat where I have my cameras.
I don't know idea what is the best convenient solution.
I'm sure that my cameras unfortunately don't have the video sending to a Ftp server in their features.
What do you suggest me?

Sent from Note 4 device - Rome - Italy

Sent from Note 4 device - Rome - Italy