Oracle Database Administration: The Essential Refe

How SQL*Net works

SQL*Net is designed to run on top of an existing network protocol, and is therefore independent of the particular hardware and software being used to implement a network. As long as SQL*Net on both sides of the connection is using the same basic protocol (e.g., TCP/IP, LU6.2 or IPX), it won’t matter to Oracle how the underlying network transports the information. Figure 5.3 shows the relationship between SQL*Net and the underlying network; it illustrates Oracle, SQL*Net, TCP/IP, and physical transport on both sides.

Figure 5-3. Relationship between SQL*Net and the underlying network

The key here is that connectivity to and from the Oracle database and tools is achieved by using SQL*Net, which presents a consistent interface to Oracle. By utilizing an appropriate protocol adapter (in this case, TCP/IP) on each side, SQL*Net is able to conform to the network protocol in use. SQL*Net creates data packets using the native network protocol, and it does not matter how the network is implemented to actually carry the SQL*Net packets. In fact, SQL*Net does not even know if a network exists, and it is possible to use SQL*Net without any network at all by making an internal connection between a client process and a server running on the same machine.

SQL*Net protocol adapters are available to support a variety of network protocols, including:

TCP/IP

Probably the most common universal ...