Feature Description

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

N28 Interface

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.

    Note
    Intermediate 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.