One side replication database

Hi all

I need to organize the transfer of data from one database server to another (assume from the primary to secondary). Database must be identical. Secondary server does not have network access to the primary server, only the primary to the secondary. Off mode and immediately disappears because in this case, the secondary server must met network access to the primary. There is an option to Datapump, ie do a dump pass it to the secondary, and there it is imported. Just still have the option to transportable tablespaces. What other options for replication in one thoron. Who has any experience, please share tips and advice