Offline Static or Predefined Rules

The following call flow and procedure describes the Usage report in N4 session report with Volume/Time threshold for the offline Bearer or SDF level, or SDF level URR for Predefined and Static Rules.

Call Flow for Usage Report in N4 Session Report for Offline Static or Predefined Rules
Call Flow Description for Offline Static or Predefined Rules
Step Description
1

PCRF performs Gx-CCR or CCA exchange with SMF. In this exchange, the SMF receives Predefined Rules for default bearer from the PCRF.

2

SMF initiates N4 session establishment request exchange with UPF. In the same request, UPF relays the PFCP message exchange.as response.

3

SMF sends Create session request to the S-GW and GTPP response message is exchanged.

Note
Volume/Time threshold is detected at UPF and UPF prepares Usage report with VOLTH/TIMTH for the offline Bearer/SDF level or SDF level URR.

4

SMF sends N4 Session Report Request/Response exchange with offline Volume/Time threshold.

When SMF receives the SDF level or Bearer/SDF level usage report with VOLTH/TIMTH for static/predefined rules, the Bearer/SDF level URR is created at SMF if not there, and the SDF level URR gets linked to the Bearer level URR.

5

SMF sends GTPP Data Record Transfer Request with SDF Containers to the Offline Charging Server (OFCS). This request is sent with one or multiple SDFs with volume usage and serviceConditionChange—one for each RG+service ID.

Note
The algorithm works based one of the following conditions:
  • If the offline Bearer Usage report is received along with the SDF or SDF Usage report received and a maximum charging condition is hit (max-losdv CLI configured value – default value is 1).

  • If the offline Usage report received is without measurement for the Bearer level Time threshold in the N4 Session Report Request, then the GTPP Data Record Transfer message with recordClosureReason “TimeLimit” without SDF Containers gets exchanged with OFCS.

  • If the offline usage report received is without measurement for the SDF level Time threshold in the N4 Session Report Request, then the GTPP Data Record Transfer message does not get exchanged with OFCS.

6

OFCS sends GTPP Data Record transfer response to the SMF.

Sample Configuration

The following is a sample message output for offline SDF level URR Id for static rule Usage report:

URR ID:
                Type: 81   Length: 4
                Value: 0x80000021.  
            USAGE REPORT TRIGGER: 
                Type: 63  
                Vol Threshold
            VOLUME MEASUREMENT: 
                Type: 66  
                Total Volume: 400
                Uplink Volume: 200
                Downlink Volume: 200

                
        accessPointNameNi                    cisco.com  
        ratingGroup                          101
        chargingRuleBaseName                 prepaid
        resultCode                           2001
        localSequenceNumber                  1
        timeOfFirstUsage                     220920093554-0400
        timeOfLastUsage                      220920093558-0400
        timeUsage                            4
        serviceConditionChange               Volume Exhaust
         qCI                                  5
         maxRequestedBandwithUL               512000
         maxRequestedBandwithDL               512000
         guaranteedBitrateUL                  0
         guaranteedBitrateDL                  0
         aRP                                  84
        servingNodeAddress                   192.60.7.31
        datavolumeFBCUplink                  200
        datavolumeFBCDownlink                200
        timeOfReport                         220920093601-0400
        userLocationInformation              
         Location Type                    CGI
          MCC                                404
          MNC                                43
          LAC                                0x84C
          CI                                 0x4F0A