Back up Windows data to a Linux server across the internet
I am meeting with a business owner on Thursday to discuss setting up a data backup service. He has several clients, all running MS Windows, and he wants them to be able to make backups across the internet to his server.
I think I can convince him to set up a Linux box for the backup server, and I am prepared to give him tech support.
I would like suggestions on what technologies would work well together to automate this. I'm kind of thinking that SSH is probably the most secure method of transferring the data. Once I get the data on the Linux server, I think I can figure out what to do from there. But it's been a long time since I've done any type of admin work on Windows. I don't even know how to schedule "cron" jobs. I think that putty will provide the Windows vehicle for SSH, but I don't know how to do the preliminary stuff on the client. I would like to be able to rsync somehow so I don't have to shoot the whole 9 yards across the wire every time.
I'd also like opinions on the relative merits of pushing vs. pulling the backup data. I don't even know yet whether the clients have computers with static IP's, so I don't know if pulling is even an option. Would pulling require more strict firewall configuration on the clients than if the client initiated the connection?
Any ideas or opinions are welcome. Thanks in advance for any insights you can give me.