A.3 Example Information flows for subscriptions to notifications

23.3353GPPRelease 17Stage 2Technical realization and information flowsTSUser Data Convergence (UDC)

A.3.1 General

When an UDC-external entity subscribes/un-subscribes to notifications of specific events which occurs on specific user data stored in the UDR, the application front-end should perform a subscription procedure towards the UDR.

The following flows show examples of an application server subscription to notification and un-subscription to notification in IMS network. These scenarios do not address the mechanisms for access authorisation in the UDR.

A.3.2 Application Server Subscription information flow example

Figure A.3.2-1 Subscription over Sh with Ud subscription from HSS-FE

1. AS sends the Sh-Subs-Notif request to the HSS-FE to subscribe or un-subscribe to the notifications of changes on the Repository Data with the related Public User Identity, the Service Indication, the Application Server Identity, the Expiry Time (not for un-subscribing) and other information.

2. Upon reception of the Sh-Subs-Notif request, the HSS-FE checks the AS-permission list to see whether the AS is allowed to contact the HSS. If so, the HSS-FE sends the Query Request to the UDR to fetch the user data needed to process the Sh-Subs-Notify request from the UDR.

3. After applying the access control, the UDR responds to the HSS-FE with the requested data.

4. The FE sends a Subscription Request to the UDR.

The Subscription Request message includes:

– The Application type of the FE

– Application FE identity

– Public User Identity

– Subscription Type: indicates whether this request is to subscribe or to un-subscribe.

– Notification Type

– the following Subscription-to-Notifications information:

– Identification of the requested data: Repository Data with Service Indication.

– The notification condition: change on user data.

– The original entity identity: Application Server Identity which issues the Sh-Subs-Notif request.

– The expiry time: the Expiry Time in the Sh-Subs-Notif Request, if any (possibly modified by the HSS-FE); expiry time is not applicable for un-subscriptions.

5. The UDR checks whether the subscription/un-subscription is allowed. If it is permitted, the UDR shall store/delete the Subscription-to-Notification information. The UDR responds with the Success Indication.

6. Upon reception the Subscription Response, the HSS-FE sends the Sh-Subs-Notif Resp to the AS with the value of the requested data and with the result code set to DIAMETER_SUCCESS.