How does Windows 7 determine whether the connection to the network is considered 'online'? We currently have offline files enabled and the way (I assume) its supposed to work is that once you disconnect from the corporate network, Windows will use the offline files cache and the computer will be considered 'offline'. When it reconnects to the corporate LAN it then is considered 'online' and will synch any changes made to files in the offline files cache. When connecting via VPN, how then does Windows determine whether it is online or offline? Is there particular ports or VPN concentrator configuration required for this to be more stable?

To the best of my knowledge, it uses ping to determine if the server is online and available. So through the VPN it should be online if there is sufficient bandwidth avaiable. Here is a great article on Offline Files new feature for Windows 7... http://trycatch.be/blogs/roggenk/archive/2009/06/16/windows-7-offline-files-amp-folders-transparent-caching.aspx