In some cases there are Internet clients with a large amount of data and a slow Internet connection, so an initial (file) backup would take too long.
In this case you could copy the Internet client's files to an external disk. Then carry the disk to your server's location, configure a UrBackup client in the server's network to backup the disk's contents and then wait for the local backup to finish. The client can also be installed on the server, i.e. you could connect the disk to the server, install the UrBackup client on the server and configure it to backup the disk.
After the local backup is finished UrBackup will not load identical files from the remote client if "Calculate file-hashes on the client" is enabled in the Internet settings (it is enabled by default). After the file backup of the remote client is finished you can remove the local client or delete it's file backups.