The image shows how client applications, network components, and clustered database nodes communicate using sqlnet and Oracle Notification Service messages for notifications and status updates. A network communication flow between a Client Network, Oracle Connection Manager (CMAN, and a Database Network.

Oracle Connection Manager (CMAN hosts the following:

• CMAN.
• Oracle Notification Service represented by a bell icon labeled ONS Proxy.

Database Network: Hosts Oracle Clusterware with two instances:

• Instance 1 with a database Oracle Notification Service Daemon.
• Instance 2 with the same labels as Instance 1.

The connection arrows indicate communication flow:

• The Client host and CMAN exchange sqlnet traffic with database instances in Oracle Clusterware.
• The Client host subscribes and publishes to the ONS Proxy in Oracle Notification Service in the CMAN.
• The ONS Proxy subscribes and publishes to the Oracle Notification Service Daemon in both database instances.