John,
It only works when users are logged in to the Network. This option is used to backup Laptops that are "mobile", when they come back home to your network they are logged in and then data the data is backed up to the network, in our case we make all the user junk go to the NAS, then the NAS or NDMP backup.
Can you imagine backn up a Laptop that has gigs of info over a wireless connection. Can you say Oww Oww Owwwwch....
It does make the execs happy that they can have their data back when their drive goes south.
JD