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Oracle Net Basic Concepts

Changes in Oracle Net Services 12c Release 1 (12.1)

The following are changes in Oracle Database Net Services Administrator's Guide for Oracle Database 12c Release 1 (12.1):
  1. New Features
  2. Deprecated Features
  3. Desupported Features

New Features

The following are the new features in Oracle Net Services:
  1. Larger Session Data Unit Sizes Oracle Net supports large session data unit (SDU) sizes, with a new upper limit of 2 MB. The larger SDU size can be used to achieve better utilization of available network bandwidth in networks that have high bandwidth delay products and host resources, according to application characteristics.
  2. Advance Network Compression Advanced Network Compression is another new feature that reduces the amount of data transmitted over the network. New parameters for the sqlnet.ora file enable compression and selection of the preferred compression level. Advance Network Compression is available as part of Advanced Compression Option.
  3. Terminated Client Detection Terminated client detection has been enhanced to reduce the amount of time taken to detect terminated connections. The SQLNET.EXPIRE_TIME parameter must be set in the sqlnet.ora file to detect terminated clients. If the system supports TCP keepalive tuning, then Oracle Net Services automatically uses the enhanced detection model, and tunes the TCP keepalive parameters.
  4. Intelligent Client Connection This feature reduces the priority of connection attempts to unresponsive nodes in the address string of connect descriptor. No configuration changes are required to use this feature.
  5. Incident Generation for Process Failures In case of a process failure, an incident is generated for the following Oracle Net Services components:
    1. Oracle Net Listener
    2. Listener control utility (LSNRCTL)
    3. Connection Manager Administration (CMADMIN)
    4. Oracle Connection Manager gateway (CMGW)
    An incident includes the call stack as well as diagnostic information. Incident generation works with Automatic Diagnostic Repository (ADR) to organize the dump information for critical errors into incidents. If ADR is disabled, then incident generation is also disabled.
  6. Valid Node Checking for Registration Oracle Net Listener allows screening of service registration requests from database instances. A database instance is allowed to register services if the instance is running on a valid node. Database administrators specify a list of valid nodes and excluded nodes. The list of valid nodes specifies hosts and subnets from which instances can register services with the listener. The list of excluded nodes specifies hosts and subnets from which instances are not allowed to register services with the listener. The database administrator can also disable valid node checking.
    By default, valid node checking for registration (VNCR) is enabled, and registration is allowed from instances running on the local host. Subnets or remote hosts need to be configured in the list of valid nodes. This configuration is performed automatically for Single Client Access Name (SCAN) listeners as part of an Oracle Real Application Clusters installation.

Deprecated Features

The following features are being deprecated in Oracle Database. This is based on an effort to streamline configuration and use of Oracle Database.
  1. NT LAN Manager (NTLM) protocol for domain authentication NTLM domain authentication has been deprecated from the Oracle Windows adapter. Only Kerberos authentication is used for the NTS adapter. NTLM is still used for local user authentication, as well as in the case in which the database service runs as a local user.
  2. Oracle Restart Oracle Restart is provided as part of Oracle Grid Infrastructure. Oracle Restart monitors and can restart Oracle Database instances, Oracle Net Listeners, and Oracle Automatic Storage Management (Oracle ASM) instances. Oracle Restart is restricted to manage single instance Oracle Databases and Oracle ASM instances only, and is subject to desupport in future releases. Oracle continues to provide Oracle ASM as part of the Oracle Grid Infrastructure installation for Standalone and Cluster deployments.
  3. The following parameter has been deprecated:

Desupported Features

Some features previously described are desupported in Oracle Database 12c Release 1 (12.1)
  1. Oracle Net Connection Pooling
  2. Oracle Names
  3. Oracle Net Listener Password
  4. Unsupported Parameters The following parameter is no longer supported:

Legacy Concepts and Terms

Net Allows Oracle client applications to communicate with a database
Net Adapter Translates between Net and an underlying network protocol such as TCP/IP.
Net Listener Software that runs on the database server that handles incoming network requests.
Listener.ora A file on the server that tells the Net Listener which databases clients may connect to.
Tnsnames.ora A file on the client that contains a list of databases and servers that may be reached from that client.