Handling a CHF Server Failure

The CHF server failure occurs when the selected CHF sends failure response or sends no response. For a CHF server failure, the NF library sends status code that is based on the failure template. This template is associated with the CHF network profile. The smf-service sends the profile information to smf-rest-ep while sending the IPC message.

The failure template is configured with the list of HTTP error codes and the associated failure actions and retry count, as required. Following are the failure actions as available in the feature template for this feature:

  • Retry and Continue—For this failure action, NF library attempts until the configured number of times before fallback. After the configured number of times completes, the NF library falls back to the lower priority CHF server IP address. If the failure or no response is received from CHF server, the "continue" action is returned to the smf-service.

  • Terminate—For this failure action, NF library does not attempt to send message to other CHF servers. The library sends a reply to smf-service with the action as "terminate". For the "terminate" failure action, the smf-service deletes the session.

  • Continue—For this failure action, the smf-service continues the session and sends the charging message to the offline CHF server. This server is configured as part of the local static CHF profile that is meant for the offline purpose. In addition, the failure handling profile for offline CHF is configured.

Note

For the "continue" failure action, you must configure the offline CHF server at SMF in a separate profile. SMF will use this profile after the CHF server failure. If the offline CHF server is not confgured, the session is continued without imposing any charging.