Can I backup data to TeraStation that belongs to another network or to TeraStation connected with VPN?

Yes.
The TeraStation can backup to a TeraStation on another network as long as the two networks are connected by a VPN.

However, it is necessary to enter the IP address of the backup target TeraStation for the operation because the TeraStation can backup only to the TeraStation in the same network.
Follow the procedure below to enter IP address.

1. Navigate to [System] – [Backup] – [View NAS Devices] in the Web Admin interface.
2. Under [Off Subnet TeraStation], enter the IP address of the target TeraStation in the [New IP Address] field, and click [Add].