Integrating Network Devices into the SRC Network Overview
You can integrate third-party routers and other network devices into your SRC network. The SAE provides a driver that you can use to integrate the SAE with a third-party device. This device driver uses the session store to store and replicate subscriber and service session data within a community of SAEs.
To log in subscribers to the SAE, you use assigned IP subscribers or event notification from an IP address manager.
To activate services and provision policies on the device, you use script services. You can also activate aggregate services for subscribers. However, you cannot activate normal services that require policies to be provisioned on the device.
For SAE redundancy in an SRC network, you can have a community of two or more SAEs. SAEs in a community are given the role of either active SAE or passive SAE. The active SAE manages the connection to the network device and keeps session data up to date within the community. Figure 11 shows a typical SAE community.
When an SAE starts, it negotiates with other SAEs to determine which SAE controls the network device. The SAE community manager and members of the community select the active SAE.
A passive SAE needs to take over as active SAE in any of the following cases:
The active SAE shuts down. In this case, the active SAE notifies the passive SAEs, and one of the passive SAEs takes over as active SAE.
A passive SAE does not receive a keepalive message from the active SAE within the keepalive interval. In this case, the passive SAE attempts to become the active SAE.
Storing Session Data
To aid in recovering from an SAE failover, the SAE stores subscriber and service session data. When the SAE manages a network device, session data is stored in the SAE host’s file system. The SRC component that controls the storage of session data on the SAE is called the session store. The session store queues data and then writes the data to session store files on the SAE host’s disk. Once the data is written to disk, it can survive a server reboot.
For more information, see Storing Subscriber and Service Session Data.
Using Script Services to Provision Third-Party Devices
You use script services to activate services and provision policies on third-party network devices. A script service is a service into which you can insert or reference a script. You write a script that will activate services and provision policies on the third-party device, and then you insert the script into the script service or reference the script in the service. When the SAE activates a service, it runs the script. The script provisions policies on the device using a means that the device supports. You can also include an interface in the script that causes the SAE to send authentication and tracking events when it activates, modifies, or deactivates a script service session.
The SAE core API includes two interfaces for creating a script:
ScriptService—Defines a service provider interface (SPI) that the script service must implement. The implementation of the ScriptService interface activates, modifies, or deactivates the service.
ServiceSessionInfo—Provides a callback interface into the SAE and provides information about the service session to the script service.
For information about the ScriptService interface and the ServiceSessionInfo interface, see the script service documentation in the SAE core API documentation on the Juniper Networks website at https://www.juniper.net/documentation/software/management/src/api-index.html
You can write the script in Java or Jython.