Appendix A Policy Agent Architecture

The policy agent controls the information sent to and received from all other components, and the policies that they operate. It is implemented using the Java Dynamic Management Kit framework. It contains a set of m-beans and their exported interfaces.

Figure A-1 Policy Agent Components

The policy agent contains the following management beans (m-beans):

• Configuration m-bean

  The policy agent contains a configuration m-bean which handles both static and dynamic configuration.

  The static configuration contains the configuration information that you set using the configuration tool.

  The dynamic configuration contains the configuration information currently being used by the kernel module. This includes the static and volatile configuration relating to flows.

• Directory m-bean

  The directory m-bean contains information used when interacting with a directory service. There are three policies:

  • Load all the rules at start time.

  • Load relevant rules when a new flow is detected.

  • Modify the configuration when a directory event has occurred (see "Directory Event Processing").

• Statistics and Accounting m-bean

  This m-bean uses the JDBC interface to write flow statistics to a text file after 30 seconds of flow activity.

• Configuration Interface

  Communicates the configuration interface between the policy agent and the kernel. Also used by SNMP monitoring

• Accounting Interface

  Communicates statistics and accounting information between the policy agent and the kernel. Also used by SNMP monitoring, and by the C statistics API.