Feature Description
The N28 interface supports the key charging and quota handling scenarios.

PCF performs the following capabilities through the N28 interface:
-
Retrieving or subscribing to policy counter information from Charging Function (CHF) over N28 for use in policy decisions over N7 only. This includes subscription to specific counters or all.
-
Support for receiving notifications for policy counter information changes from CHF and using the information for policy decisions.
-
Support for using the retrieved counters in policy decisions through Virtual Services (VS).
-
This includes subscription to specific counters or all Support for Service Based Architecture (SBA) interface toward CHF. Currently, it supports:
-
Initial Subscribe toward CHF on N7 session creation (if enabled).
-
Notify from CHF.
-
Unsubscribe toward CHF on N7 session termination.
NoteIntermediate Subscribe and CHF driven termination is currently not supported. -
-
NRF discovery of CHF:
-
PCF also supports the local configuration for CHF endpoints.
-
If CHF endpoints are configured locally, the configured endpoints are used, and discovery may be skipped.
-
Currently discovery is only supported by NFType and does not support any criteria.
-
-
Endpoints caching - Locally cache and reuse of the discovered CHF endpoints for sending N28 messages.
-
Random Load Balancing for cached Endpoints.