This illustration depicts the layers of stack communication used in an initial connection. On the client side, from the top down, the stack includes the following layers:

• Client Application (uses OCI)

• Presentation - TTC

• Oracle Net Foundation Layer

• Oracle Protocol Support

• Transport Protocol (TCP/IP, TCP/IP with SSL,SDP, and Named Pipes)

On the server side, from the top down, the stack includes the following layers:

• Listener and RDBMS

• Oracle Net Foundation Layer

• Oracle Protocol Support

• Transport Protocol (TCP/IP, TCP/IP with SSL, SDP, and Named Pipes)