Configuring Push Notification Service for Unregistered Users

This section describes how to configure the device to handle push notifications for users who are not registered with the device. This type of service, called Dynamic Push Notification Service, enables the device to route incoming calls to mobile application users without requiring them to maintain a permanent (and prior) SIP registration. This capability is designed for large-scale mobile application deployments where maintaining persistent registrations for millions of dormant users is impractical.

When the device receives an incoming SIP INVITE request for an unregistered destination user, it handles Dynamic Push Notification Service as follows:

1.

The device dynamically creates a temporary registration instance for the destination user (only URI user part). The registration instance is marked as requiring a push notification.

2.

The device sends an HTTP POST request to the Push Notification Server, prompting it to wake the user's mobile application.

3.

The Push Notification Server sends a push notification to wake the user's mobile application.

4.

The user sends a SIP REGISTER request to the device, indicating that the application is active and ready to receive the call.

5.

The device matches the incoming REGISTER request with the user's temporary registration instance in the registration database by the user part only, rather than by both user part and Contact header.

6.

After the user successfully registers with the device, the device forwards the INVITE request to the user to complete call establishment.

The following figure illustrates the push notification service process for users dynamically registered on the device:

The device rejects the call (INVITE message) with a SIP 480 (Temporarily Unavailable) response and removes the temporary registration instance for the user if any of the following occurs:

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The push notification request sent by the device to the Push Notification Server fails.

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The device doesn't receive a SIP REGISTER message from the user within a user-defined timeout. The counter of this timeout is started from when the device sends the push notification request.

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To configure Dynamic Push Notification Service for unregistered users:

1.

Configure the IP Group representing the users of the push notification service with the following special parameter settings:

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'Dynamic PNS Registration Mode': Enable

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'Registration Mode': User Initiates Registration

For more information on IP Groups, see Configuring IP Groups.

2.

Configure Call Setup Rules according to your deployment requirements to trigger the device to send an HTTP push notification request to the Push Notification Server when it receives an INVITE request destined for a user.

For more information on Call Setup Rules, see Configuring Call Setup Rules.

3.

Configure a Remote Web Service for the HTTP-based Push Notification Server. In addition to other settings as needed, configure the Remote Web Service with the following special parameter setting:

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'Type': General

For more information on Remote Web Services, see Configuring Remote Web Services.

4.

Configure the maximum time (in seconds) that the device waits for a SIP REGISTER request from the user, by using the [PNSRegisterTimeout] parameter. If the REGISTER request is not received within this interval, the device rejects the call.