It does do samba, ftp, mini dlna, upnpshare when attached hard drive is formatted fat32, ext2 but not sure about hfs.I think the issue will be whether you can format the drive as HFS+ and still have the router see it. I also think HFS+ is required for TM. For storing files other than via TM you should be able to get it running but I'm unfamiliar with that model; check their support.
To do a Time Machine backup to a networked drive like this the router will need to support AFP. I did a quick search on dd-wrt with AFP and there is quite a bit of discussion on the topic. It looks like maybe there is a patch to add AFP to dd-wrt?anyone really know about my question ?
need urgent help.