Handling Charging Disable Functionality
The SMF performs the following functions when the charging transactions are disabled on N40 interface:
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Deletes the already created Usage Reporting Rules (URR) on N4.
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Sends the proprietary IE "Charging Disabled" in subscriber params attribute through the N4 establishment or modification request.
This Custom N4 IE has some functional impact on other kinds of Charging like Radius-Accounting etc.
To eliminate the identified challenges at UPF, the SMF undergoes the following behavior changes when disabling the charging process:
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For newly loaded rules, SMF doesn't construct new dynamic URR.
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SMF stops sending the Charging Disabled IE to the UPF. The UPF continues to send the Usage Report (USAR) to the SMF for the other URRs.
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The SMF then acknowledges UPF with a successful response message. If the report demands usage quota, SMF relays infinite quota without requesting for the N40 usage details through N4 modification response.