This illustration describes Oracle's secure sockets layer (SSL) technology stack. On top of the stack is the database application layer making calls into the Oracle call interface (OCI) and two-task common. The OCI then uses Net Manager for communicating with the database server over the network.
Net Manager is an abstraction layer that supports various transport adapters, including SSL. Net Manager routes the OCI calls via the SSL adapter. The SSL adapter, in turn, uses TCP/IP and SSL libraries to perform the protocol specific action.