- 5.1 Why Push Is Important to BlackBerry Developers
- 5.2 How the Application Data Push Process Works
- 5.3 Common Questions About Push
- 5.4 Pushing to Internal Versus External Users
- 5.5 Additional Resources
5.2 How the Application Data Push Process Works
Although each push option works in a slightly different manner, Figure 5.1 shows the data push process at a high level.
Figure 5.1 BlackBerry application data push process
To push data to a BlackBerry application, the following steps are performed:
- An application creates the data that needs to be pushed to one or more devices and then sends the data to a server. The server can be inside or outside the firewall, depending on the push option being used.
- The server verifies the identity of the target recipients.
- The server notifies the push application that the data has been accepted.
- The server sends the data to the BlackBerry infrastructure.
- The BlackBerry infrastructure delivers the data to the device.
- The device receives the pushed data and returns an acknowledgment that it received the data.
- The BlackBerry infrastructure receives the notification from the device and forwards it to the push server.
- The push server returns the notification to the push application.
If the mobile user is out of coverage, the data might still be delivered when the device reappears, as long as it is within certain defined time limits. (Chapters 6 and 7 discuss these limits.) The BlackBerry infrastructure queues requests for a limited amount of time and delivers them when the device returns to coverage. When building a push application, developers must take into account that the device might not be available when the push is sent. The push request can be set up so the push application is notified when the data arrives on the device, and the push application can push the data again if the notification is not received within an expected amount of time.