Possible, if you have a high enough upload speed.
A friend and I both recently switched to Synology Network Attached Storage drives and, over the course of a few days, we started discussing the different possibilities for remote file access and centralised media libraries.
We’d both gotten our hands on Synology DS411j network drives, which come with A LOT of features that you can use to manage your files and connectivity in different ways.
One feature that looked promising was the secure WebDAV protocol which allows for remote file access over a secure HTTPS connection (that’s the same sort of security that you’d get for online banking, etc.).
The reason I thought it was promising was because I’d stumbled across WebDAV before, as an option for file sharing in XBMC.
Initial trials over my home Internet connection proved promising. I only had a 1Mbps upload speed but I was able to stream my MP3 library with no problems.
Video was another story. I could establish a connection and browse my library, but my home upload speed just wasn’t fast enough to stream even standard definition stuff over the web.
Then I realised that I was out of the contract period with my ADSL provider, and that Virgin offer up to 50Mbps fibre optic broadband in my area, with a 5Mbps upload speed.
Fast forward to this morning and I’m now piped up for “super-fast” broadband and the results are as follows:
There you go, XBMC video streaming from a “home” based source.
A full walkthrough on how to achieve something similar will shortly be on the site.