Not possible at the current time for automatic backup to NAS. Microsoft wants you to use their cloud services, not your cloud services, so it hasn't been included.
When you say, "All Data", do you mean things like photos and music? Or are you wanting to include app data as well? It won't be possible to write an app to do app data syncing. Would be nice, though. Not sure if an app can be written to write system settings, as they may be restricted by Microsoft. I haven't really checked into the API for that, so I don't know.
The Windows Phone app you can get for Windows 8.1 is a Metro style app that will automatically backup/synchronize certain data with your phone, but you have to connect it via USB cable in order to do it.
If you were to have it automatically backup to NAS when entering WiFi, then you'd have to be able to specify a specific WiFi, and if you ever came across a WiFi with the same SSID, then you'd be backing up to the wrong place. Food for thought.
01-08-2015 08:45 AM