Oracle Network Products Getting Started for Windows Platforms

Introducing Oracle Network Products

Oracle Connectivity Overview
Architectural Overview
Client/Server Interaction
New Features with Version 2.3.3

Oracle Connectivity Overview

Oracle Network Products' main function is to establish sessions and transfer data between a client and a server or between the two servers. Most of the activity occurs at the beginning when setting up the session. Once the session is established, Oracle Network Products' main job is to act as a data courier for the client and server.

The connection operation is initiated during any standard database login between the client application and the server, with information such as the client machine name and username being passed to the remote machine.

Oracle Network Products' coordinate a session with the help of a listener. Every time a client (or server acting as a client) requests a session with a server, the actual requests comes into a listener. The listener decides where the server is and enables the client to connect to the server. The listener is a separate process whose whole responsibility is to listen for incoming client connection requests and manage the traffic to the server.

Architectural Overview

Forming the foundation of Oracle Network Products is SQL*Net. SQL*Net uses the Transparent Network Substrate (TNS) and industry-standard network protocols (such as TCP/IP) to connect a client to a server and establish an Oracle session. Figure 1-1 shows the basic connectivity architecture:

Figure 1¯1 SQL*Net Connectivity Architecture

Following is an overview of the Oracle network connectivity components:

SQL*Net

The role of SQL*Net is to establish and maintain a connection between the client application and the server and exchange messages between them. SQL*Net is a software layer that is required to communicate between Oracle clients and servers. It provides both client-server and server-server communications across any network. It enables client tools to access, modify, share, and store data on Oracle7 servers over a network. The communication between client applications and servers takes place across one or more networks, and is referred to as client/server communication.

Transparent Network Substrate The TNS is an underlying layer of SQL*Net that receives requests, and settles all generic connectivity functions such as opening/closing a session or sending/receiving requests or responses. TNS then passes control to an Oracle Protocol Adapter to make the protocol-specific call.

Oracle Protocol Adapters

The Oracle Protocol Adapters are responsible for mapping TNS functionality to industry-standard protocols used in the client/server connection. Each adapter is responsible for mapping the equivalent functions between TNS and a specific protocol.

An Oracle Protocol Adapter translates (or adapts):

function calls of specific network protocols (such as TCP/IP) into equivalent function calls of TNS.
TNS generic function calls into specific function calls for the underlying network protocol.

Table 2-1, "Oracle Network Products Availability," lists the Oracle Protocol Adapters supported.

Additional Information See the third-party network documentation that came with your protocol software for a detailed technical discussion of these protocols.

Network-Specific Protocol Stack

The network protocol stack, not provided by Oracle, supplies a reliable means of communication.

All Oracle software in the client/server connection process requires an existing network protocol stack to make the machine-level connection between the two machines. The network protocol is responsible only for getting the data from the client machine to the server machine, at which point the data is passed to the server-side Oracle Protocol Adapter.

Client/Server Interaction

This section describes a basic client/server connection.

Client Connection Request The user requests database information from the server by supplying input to an Oracle tool running on the client machine. The Oracle tool accepts this input from the user through the keyboard and mouse, and sends it to SQL*Net to be transported across the network to the server.

An Oracle Protocol Adapter and SQL*Net on the client side take the SQL requests from the application and package them for transmission. When the Oracle7 Server replies, the data is sent back to the client machine through the same mechanism.

Server Response to Client Connection Request The server portion runs the Oracle7 database software and a SQL*Net network listener program. The SQL*Net network listener, through an Oracle Protocol Adapter, accepts connections from client applications anywhere on the network. SQL*Net and an Oracle Protocol Adapter must be installed on both the client and server for user input to be transferred from the client machine to the server machine.

Once the network package is received by the server machine, the Oracle Protocol Adapter and SQL*Net on the server side assemble the SQL statements from the network package and pass them to the Oracle7 Server database. The database performs the function requested by the user on the client machine. Finally, SQL*Net transfers the results of the database functions to the client machine.

New Features with Version 2.3.3

SQL*Net and Oracle Network Products include the following new features:

New Feature	Described in...
DECnet Protocol Adapter for Windows NT	"Supported Oracle Network Products" "Configuration Files"
LU6.2 Protocol Adapter for Windows NT	"Supported Oracle Network Products" "Configuration Files"
Identix Adapter for the Advanced Networking Option for Windows NT and Windows 95	"Supported Oracle Network Products"
NDS Naming Adapter for Windows NT and Windows 95 clients	"Supported Oracle Network Products" "Using the NDS Native Naming Adapter"
NDS Authentication Adapter for Windows NT and Windows 95 clients	"Supported Oracle Network Products" Using the NDS Authentication Adapter"
DCE Integration provided by DEC Digital	"Supported Oracle Network Products"
DCE Integration for the server	"Supported Oracle Network Products"
[Ctrl] + [C] supported for 16-bit TCP/IP	"Enabling Ctrl+C"
Oracle Trace for SQL*Net	"Oracle Trace for SQLNet"*

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