CUPS supports the Final Unit Indication (FUI) redirect feature on the Online Charging System (OCS) to configure automatic URL redirects for mobile subscribers whose quota is exhausted. When the subscriber quota is exhausted, this feature enables redirection to a pre-configured URL to recharge their account.

The OCS sends the FUI redirect information in one of the Diameter Attribute Value Pair (AVP) in the Credit Control Answer-Update (CCA-U) message. The FUI redirect information (when the feature is enabled at the OCS) is normally received when the OCS wants to indicate to the UPF that this is the last allocated unit before the subscriber quota is exhausted.

The FUI Redirection feature supports the following functionalities:

• FUI Redirection with HTTP URL

• FUI Redirection for the HTTP GET request

• Control the starting of validity timer for FUI redirect using the diameter redirect-validity-timer immediate CLI command.

  The traffic-start keyword option is not supported.

• Control the behavior of marking redirected HTTP flow as free-of-charge using the diameter fui-redirected-flow allow CLI command. The redirected traffic gets redirected if the rule is executed from FUI-Redirect.

• Appending the original URL to the redirect URL

  See the Appending Original URL to Redirect URL section for more information.