You can activate, deactivate, and modify PCC charging rules at any time during the PDU session lifetime.

PCF can modify the following attributes in a dynamic PCC rule active in the SMF:

• Charging Key

• Service Identifier

• Measurement Method

Note	No modification is supported for Gy/Gz.

Activities on PCC rules and QoS flows aren’t chargeable events. However, a change of charging rule in PCC rules leads to chargeable events. Some of the examples are the following:

• Start of service data flow.

• Termination of service data flow, for the last service data flow for the original PCC rule.

The charging key (that is, rating group) is used to request an online charging quota.

Note

Depending on the reporting level received from the PCRF: For Gy, the quota is requested based on Rating Group (RG) or Rating Group and Service ID (RG+SID). For Gz, the quota is reported based on RG or RG+SID. If no reporting level is received, then the quota is derived from rating group or service ID values received from the PCRF.

The charging identifier correlates charging information between the SMF and CHF or OCS /OFCS during the duration of a PDU session. The SMF generates and assigns a charging identifier when a PDU session is established. The charging identifier is unique for that PDU session and is used in all messages that are exchanged in that PDU session.

The SMF collects the following charging information for converged online and offline charging:

• Usage of access and core network resources: Describes the amount of data that is delivered to and forwarded from the UE.

• Usage duration: Time interval from PDU Session Establishment to PDU Session Release.

• User: UE information used by the user for a PDU session.

• Data network: Data network address as determined by the DNN.

• Start time: PDU session start time.

• User location: HPLMN and VPLMN reporting area.

For service-data flows (flow-based charging), the SMF collects the following information:

• PDU session description.

• Data that are transmitted in uplink and downlink directions based on the rating-group information, or a combination of rating-group and service ID during volume-based charging.

• Duration of service data flow based on the rating group, or a combination of rating-group and service ID during event-based charging.

• The number of events and corresponding time stamps categorized by rating group or combination of the rating group and service id when event based charging applies.

The SMF collects charging information for service data flows per UPF, within a PDU session, based on the rating-group or based on a combination of rating-group and service ID.

The SMF supports converged session-based charging (SCUR) as specified in 3GPP TS 32.290, section 5.3.2.3. If Gy is enabled, SMF supports session-based charging as specified in 3GPP TS32.299, 12.9.0 section 6.4.If Gz is enabled, SMF supports session-based charging as specified in 3GPP TS32.298, 12.9.0 section 5.1.2.2.

The SMF establishes a charging session with the CHF with the Charging Data Request and Response (Initial) exchange. During the life of the PDU session, usage is reported with a Charging Data Request or Response (Update) exchange. After the session is released, Charging Data Request or Response (Termination) messages are exchanged.

In the case of a 4G session when Gy is enabled, then SMF establishes charging session with OCS by sending credit control request and credit control response (initial) message exchange. During the PDU session, the usage is reported with credit control request and credit control response (update) messages. After the session release, credit control request and credit control response (terminate) messages are exchanged.

In the case of a 4G session when Gz enabled, then SMF creates the offline URRs, if dynamic PCC rule is received. Then, the SMF maps the PCC rule to the corresponding charging buckets (Service Data Flow (SDFs)) and sends the N4 Establishment Request towards CnPGW-U. During the life of PDU session, the usage is reported for offline SDF or Bearer-level URRs through N4 Session Report or in the N4 Delete Session Response from UPF, it may send the GTPP Data Record Transfer request towards GTPP.

Charging is enabled for a session based on the input that is received from the PCF or PCRF.

For offline charging, the SMF sends Charging Data Request Initial toward the Charging Function (CHF) based on the presence of charging descriptors and refChgData field set in the smPolicyDecision message from the PCF in the SM Policy Control Create response.

On determining if charging is required during initial session establishment or post-session establishment, charging is enabled for the PDU session. Once charging is enabled, SMF sends the Charging Data Request (Initial) Message toward the CHF.

The SMF determines the Volume/Time threshold value either locally or from the Charging Data Response. These values are used to update the Volume/Time threshold IE in URR and to set the reporting trigger accordingly. The measurement method that is used in URR is derived from charging data.

For online charging, the SMF receives the Volume/Time Threshold and Quota values from the CHF. These values are received in the Charging Data Response (Initial) or using a Charging Data Request (Update) during a PDU Session Establishment. The SMF relays these Volume/Time Threshold and quota values to the UPF in the corresponding URR.

If Gy is enabled for an SMF 4G session, the session SMF sends the Credit Control Request (Initial) towards OCS to get the Volume/Time threshold and quota values. SMF relays these values towards to the UPF in the corresponding URR. If the SMF doesn't receive the volume threshold from OCS, the SMF determines the volume threshold from the local configuration.

If Gz is enabled for an SMF 4G session, SMF sends N4 Establishment Request with default Bearer Level URR and SDF Level URR in the case of dynamic rule. In the case of static and predefined rule, URRs are created after the PFCP session Report received with Start of Traffic (SoT). Bearer Level URR TIME_THRESHOLD and VOLUME_THRESHOLD values are received from egcdr threshold values that are configured in the Rulebase profile. SDF Level URR TIME_THRESHOLD and VOLUME_THRESHOLD values are received from egcdr threshold values that are configured in Charging profile. All the SDF Level URRs are linked to Bearer Level URR.

Note	The threshold values from CHF always override the locally configured values.

The following table maps the IEs that are shared with the UPF during Create or Update URR during online or offline charging scenarios:

The following table lists the reporting triggers and their derived source:

The CHF selection can be performed through one of the following options:

1. PCF-provided one or more CHF addresses as part of the PCC rule

2. UDM-provided charging characteristics

3. NRF-based discovery

4. SMF locally provisioned charging characteristics

Important

The SMF uses one of the last two options to fetch the CHF IP address and port details. The SMF initially performs NRF-based discovery to select the CHF server. If the SMF fails to identify the server, then it uses the locally provisioned charging characteristics. If Gy is enabled, SMF uses the locally configured Diameter client profile to connect with the OCS server.Similarly, if Gz is enabled, SMF uses the locally configured GTPP profile to connect with the Offline Charging System (OFCS) server.

URR Generation Toward N4

The SMF receives charging-data and usage-monitoring-data from the PCF. Based on this information, the SMF derives URR toward N4. In case the SMF is configured with volume/time limit at the session level, the SMF creates session-level URR.

Configuration of static or predefined rules is similar to the procedures on SMF and UPF. The layout of configuration is as follows:

1. Rulebase: A one-to-many rulebase is configurable. For a single PDU session, you can activate a single rulebase any time. PCF can activate the rulebase at SMF by sending the rulebase name in the PCC rule.

2. Ruledef: Each rulebase can have one-to-many ruledef configurations. A ruledef can either be of static or predefined type. Each ruledef is assigned to a charging action.

3. Charging Action: Contains QoS and charging information.

The SMF derives charging data for each charging action in the rulebase. Charging action associated to static rules in the rulebase is immediately derived and updated in the PDU context. Charging action that is associated to predefined rules is derived and updated when PCF activates the specific predefined rule at SMF.

The charging action derived URR has the following behavior:

• Online charging is identified by the "cca charging credit " configuration under charging action.

• Offline charging is identified by the "billing action egcdr " configuration under charging action.

• Armed triggers for volume-limit and time-limit are under the gtpp group configuration, under APN. The UPF automatically detects these values and sends the respective usage reports. Gz uses triggers from the charging profile.

• The SMF, unlike the dynamic case, does not send the Create URR immediately for charging data that is derived from the configured rules.

• Using the online charging method, the UPF sends usage report with the "Start" trigger. The SMF uses CHF to derive the quota for the RG and relays the same information to the UPF in the Update URR message. In case of Gz, SMF reads the threshold values for Bearer Level URR from the rulebase and SDF Level URR threshold values from the Charging profile.

• You can configure the UPF threshold at a rulebase level. It creates a rulebase-level URR that is linked to all ruledef-level URR within the rulebase.

For a static rule, the SMF uses the active charging service configuration during run time to derive the QoS Descriptor information to be relayed towards CHF.

For predefined rules, the associated charging action results in creation of QoS Descriptor in session data with a combination of Rating Group (RG), service ID, and bandwidth ID values. When SMF relays the usage report to CHF, it checks for a match against the RG and service ID and uses the QoS that is applicable for the matched charging action.

Important

If two predefined rules are simultaneously activated and the associated charging actions have the same RG and service ID but different bandwidth IDs, then the SMF checks if a match is found against the RG and service ID and uses the QoS that is applicable for the matched charging action. The SMF randomly selects the QoS Descriptor that is derived from one of the charging actions associated to the different predefined rules.

Note	The preceding behavior is applicable to Gy as well.

If you have configured session-level volume or time value locally or have received them from the CHF, the SMF creates session-level URR and links it to all URR corresponding to offline charging descriptors.

If PCF receives multiple charging descriptors that are of the same rating group, the SMF creates extra URR and links it to all URR derived from charging descriptors of the same rating group.

The following figure illustrates how local configuration works.

• The SMF supports up to 16 charging characteristic profiles.

• Each CC profile comprises charging group and charging profile.

• The charging server group and charging profile are linked to the DNN profile. Currently, the charging profile supports configuration for trigger and thresholds.

The SMF relays the offline resource usage report from the UPF to the CHF if any of the following conditions is met:

• Reporting type is immediate.

• Reporting type is deferred and the maximum number of deferred reportings is crossed.

The usage report includes the charging records with zero value as well. These zero value records (UUC and CDR-U) occupy unnecessary disk space on the CHF. To avoid this issue, the SMF leverages new configuration to control the offline charging records with zero byte data count.

When you configure the offline zero-usage CLI command in the Charging Profile configuration mode, the SMF relays the usage to the CHF without any overload of UUC or CDR-U.

The users can select the UUC or CDRs they want to suppress based on the CLI configuration.

Important

The CDR release is never suppressed even if the offline zero-usage drop cdr command is configured in the Charging Profile configuration mode.

To support the zero suppress CDR, enable the suppress-cdrs CLI for Gz.

For details on the configuration, see the Charging Profile Configuration section.

This section shows the following call flows:

The SMF Charging feature has the following limitations on the N4 interface:

• If the session-level URR (CDR-I) is created once, it remains active throughout the session. This URR is not deleted in the subsequent session (CDR-U).

• If the session-level URR is not created, then it is not created in the subsequent CDR-U even if the session limits are available.

The SMF is compliant with the 3GPP June 2019 specification TS 32.290 version 15.3.0.

For the June release, the messages goes over the version "v2" as indicated in the following URI format:

nchf-convergedcharging/v2/chargingdata 

The CLI command for compliance configuration is: service nchf-convergedcharging . If this CLI command or version is not configured, the default version from 3GPP December 2018 is applied.

With the 3GPP June 2019 compliance, the following information elements (IE) are added:

• Authorized QoS

• Subscribed QoS

• IEs in QoSData

• Serving Network Function ID

Use the following configuration to configure a DNN profile for SMF Charging.

config 
   profile dnn profile_name 
      charging-profile profile_name 
      network-element-profiles [ chf profile_name | ocs profile_name ]  
      end 

NOTES:

• charging-profile : Specifies the Charging Profile configuration.

• network-element-profiles : Specifies the network element profile. Network element profile can be one of the following:

  chf : Specifies the CHF network element profile.

  ocs : Specifies the OCS network element profile.

• profile_name : Specifies the name of selected network element profile. After you select the network profile, enter a string.

Use the following configuration to configure charging characteristics profile for SMF Charging.

config 
   profile charging-characteristics cc_value 
      charging-profile profile_name network-element-profile-list chf chf_name 
      end 

NOTES:

• cc_value : Specifies the charging characteristics value, which must be a 1 to 4 digit hexadecimal string in the range of 0x1 to 0xffff. For example, 11AB.

Use the following configuration to configure the charging characteristics ID, which is used to select the charging profile, if you have enabled the offline charging.

config 
   profile dnn intershat charging-characteristics-id cc_id_value 
      end 

NOTES:

• profile dnn intershat charging-characteristics-id cc_id_value : Specify the charging characteristics ID value, which must be a 1 to 4 digit hexadecimal string in the range of 0x1 to 0xffff. For example, 11AB.

Use the following configuration to configure the charging profile parameters for SMF charging.

config 
   profile charging profile_name  
      limit [ rating-group ] { duration duration_value | volume volume_value } 
      max-charging-condition max_cc_value  
      max-deferred-urr max_urr_value  
      method { none | offline | online } 
      offline zero-usage [ drop { cdr | uuc } | measurement { duration | volume } | trigger { external | final | internal } ] 
      query-all-urr { false | true } 
      quota request [ always | standard ] 
      quota suppress triggers [ qht ] 
      reporting-level { offline | online { [rating-group]  
      | rating-group | service-id } 
      requested-service-unit time seconds volume downlink downlink_value  
      uplink uplink_value total total_value 
      tight-interworking-mode { false | true } 
      triggers session session_level_triggers 
      session-failover { false | true } 
      send charging-initial  { session-start | traffic-start } 
      dynamic-rules request-quota { on-receiving-rule | on-traffic-match } 
      quota validity-time  validity_time 
      quota volume-threshold percent  volume_threshold_percent 
      usage-reporting quota-to-report based-on-grant { report-only-granted-volume } 
      mscc-final-unit-action terminate session 
      max-secondary-rat-reports report_range 
      egcdr losdv-max-containers container_num 
      egcdr service-data-flow threshold { {volume | interval } { downlink | total | uplink }  bytes | {interval  <duration>} 
      egcdr closure-reason { admin-disconnect | normal-release | } 
      egcdr triggers {qos-change | uli-change | ms-timezone-change} 
      egcdr suppress-cdrs zero-volume triggers { external-trigger-cdr  final-cdr  internal-trigger-cdr } 
      egcdr-final-record closing-cause [ same-in-all-partials | unique ] 
      end 

NOTES:

• limit : Specifies the threshold limit.

• duration : Specifies the duration threshold for charging. The threshold value ranges from 0 through 2147483647.

• volume : Specifies the volume threshold for charging. The threshold value ranges from 0 through 9223372036854775807.

• rating-group : Specifies the volume and duration threshold for a Rating Group.

• max-charging-condition max_cc_value : Specifies the maximum number of changes to the charging condition. max_cc_value must be an integer ranging from 0 through 500. The default value is 20.

• max-deferred-urr max_urr_value : Specifies the maximum number of deferred USU containers. max_urr_value must be an integer ranging from 0 through 200. The default value is 50.

• method : Specifies the charging method. The default charging method is offline.

• offline zero-usage { drop | measurement | trigger } : The SMF suppresses the offline URR with zero volume and duration. By default, the zero usage drop configuration is disabled on SMF.

  • drop { cdr | uuc } : The SMF suppresses the CDR or UUC with zero usage. If there are mutiple reports, then the SMF drops only the reports with zero usage. Note that there is no impact on the online reporting.

    If the drop command is not configured, the SMF stops sending UUC for the offline usage report.

  • measurement { duration | volume } : The SMF specifies the measurement method of the network usage for suppression. The measurement method is based on volume and duration.

    If the measurement command is not configured, the SMF suppresses the records with both zero volume and zero duration, or the records with zero volume or zero duration depending on the configuration.

  • trigger { external | final | internal } : Specifies the list of triggers to be suppressed.

    • external : The SMF suppresses the usage reports that are generated due to external triggers, such as QoS Change, RAT change, User Location change, and PLMN Change.

    • final : The SMF suppresses the usage reports that are generated at the end of a context.

    • internal : The SMF suppresses the usage reports that are generated due to internal triggers such as, volume limit, time limit, and tariff change.

• query-all-urr { false | true } : Specify to query all URRs. By default, this configuration is enabled (set to true).

  If this CLI command is disabled (configured to false) or the CC trigger is not armed at session level, the SMF will send QUERY_URR and report CC events along with usage report.

• quota request [ always | standard ] : Controls the requesting of quota from the CHF for online charging services based on the configuration. If the quota request always is configured, the SMF always requests for quota. If the no quota request or quota request standard CLI command is configured, then the SMF requests the quota for specific trigger types as defined in standard, which is the default behaviour.

• quota suppress triggers [ qht ] : Suppresses the quota from the CHF upon configuring the usage report trigger type "qht".

• reporting-level : Specifies the reporting level configuration to be used for offline and online charging.

  The default value is [rating-group] level.

• requested-service-unit: Configures the value for the requested service units.

  • time seconds : Configures the time quota value in seconds from 1 through 4000000000.

  • downlink downlink_value : Configures the downlink volume in bytes from 1 through 4000000000.

  • uplink uplink_value : Configures the uplink volume in bytes from 1 through 4000000000.

  • total total_value : Configures the total volume in bytes from 1 through 4000000000.

• tight-interworking-mode : Configuration to enable tight interworking mode for online or offline charging methods.

• triggers : Specifies the list of triggers to be configured.

• session session_level_triggers : Specifies the list for Session Level Triggers. The list of Session Level Triggers is as follows:

  • repor3gpp-ps-change

  • ambr-change

  • max-number-of-changes-in-charging-conditions

  • plmn-change

  • qos-change

  • rat-change

  • serv-node-change

  • tarrif-time-change

  • ue-pra-change

  • ue-time-change

  • upf-add

  • upf-rem

  • user-loc-change

• session-failover { false | true } : Enable Diameter session failover for Gy. The default value of this configuration is false .

• send charging-initial { session-start | traffic-start } : Specify whether to send CCR-I message towards OCS when dynamic and predefined rules are received, otherwise CCR-I message sends the usage report received with the start of traffic. The default value is session-start .

• dynamic-rules request-quota { on-receiving-rule | on-traffic-match } : Specify whether to send CCR-I message with RSU when dynamic rules received, otherwise CCR-I message sends the usage report received with start of traffic along with RSU. The default value is on-receiving-rule .

• quota validity-time validity_time : Specify the validity lifetime of the quota in seconds 1 through 4000000.

• quota volume-threshold percent volume_threshold_percent : Specify the volume threshold value as a percentage of the volume quota 1 through 100.

• usage-reporting quota-to-report based-on-grant { report-only-granted-volume } : The based-on-grant option specifies the report volume or duration in Used Service Unit to OCS if only it is granted in Granted Service Unit by OCS server. The report-only-granted-volume option specifies the filter for sending Used Volume quota to OCS base on Input, Output, or Total Octets granted in Granted Service Unit by OCS server.

• mscc-final-unit-action terminate session : Terminate the session when MSCC final unit action is terminate.

• max-secondary-rat-reports report_range : Configure the maximum number of secondary RAT usage reports to trigger the GTPP (Gz) update. report_range must be an integer in the range of 0 to 50. The recommended value for secondary RAT usage limit for max-secondary-rat-reports is 25.

• egcdr losdv-max-containers container_num : Specify the maximum List of Service Data containers (LOSDV) for creating a GTPP data record. The default value is 1.

• egcdr service-data-flow threshold { {volume | interval } { downlink | total | uplink } bytes | {interval <duration>} : Specify the SDF level offline URR threshold values. The limit for the number of downlink, total, or uplink octets must be an integer in the range of 100000-4000000000.

  • egcdr service-data-flow threshold intervalduration : Configure the threshold for offline charging. The threshold interval value must be an integer in the range of 60–40000000.

• egcdr closure-reason { admin-disconnect | normal-release | } : Configure the closure reason.

• egcdr triggers {qos-change | uli-change | ms-timezone-change} : Enable the triggers for CDR.

• egcdr suppress-cdrs zero-volume triggers { external-trigger-cdr final-cdr internal-trigger-cdr } :

  • egcdr suppress-cdrs zero-volume : Suppress the CDRs.

  • triggers : Configure one of the list of triggers that can be used to suppress CDR with zero volume.

  • egcdr suppress-cdrs zero-volume triggers internal-trigger-cdr : Specify that an Async volume usage reporting is from UPF through PFCP session usage report.

  • egcdr suppress-cdrs zero-volume triggers final-cdr internal-trigger-cdr : Specify that a call is getting terminated.

  • egcdr suppress-cdrs zero-volume triggers external-trigger-cdr : Specify that a Sync volume usage reporting is from UPF through Query URR.

• egcdr-final-record closing-cause [ same-in-all-partials | unique ]

  • egcdr-final-record : Configure the final CDR.

  • closing-cause [ same-in-all-partials | unique ] : Configure the closing cause in case of the final CDR. The same-in-all-partials value specifies that the same closing cause is to be included for multiple final CDRs. The unique value specifies that the closing cause for final CDR is to be unique.

The following is a sample configuration for SMF Charging:

config
   profile dnn intershat1
   charging-profile chgprf1
   exit
   profile charging chgprf2
   limit volume 15000
   limit duration 90
   limit rating-group volume 12000
   limit rating-group duration 80
   triggers session [ ambr-change qos-change max-number-of-changes-in-charging-conditions ]
   max-charging-condition 1
   max-deferred-urr 3
   reporting-level online service-id
   reporting-level offline service-id
   session-failover   true
   quota validity-time 200
   quota volume-threshold percent 80
   dynamic-rules request-quota on-traffic-match
   send charging-initial traffic-start
   usage-reporting quotas-to-report based-on-grant
   mscc-final-unit-action terminate session
   max-secondary-rat-reports 25
   egcdr losdv-max-containers 2
   egcdr service-data-flow threshold volume downlink 100000
   cdr service-data-flow threshold interval 100
   egcdr closure-reason normal-release 
   egcdr triggers ms-timezone-change
   egcdr suppress-cdrs zero-volume triggers 
   egcdr-final-record closing-cause [ same-in-all-partials | unique ]

exit

The SMF provides the different reporting levels for online and offline charging with the following rules:

• Configured rules are derived from the static or predefined charging actions.

• Session-level Usage Reporting Rule (URR) is derived from CHF trigger or local configuration.

• The SMF does not associate session-level URR for online and offline method charging description.

• The SMF does not associate session-level URR to the configured charging-action URRs.

• Rulebase URR is applicable only for the offline configured URR.

• For the configured online or online-offline charging method, if Ignore Service ID configuration exists, the URR list must contain "rg x urr-id y". Else, the SMF drops the charging actions as malformed.

Important

The SMF supports multiple charging methods within the same rating group.

This feature has the following limitations:

• Tight interworking mode is not supported for the service which is at the rating group level.

• One service at the rating group level and another service at service ID level are not supported.

The Different Reporting Level Support for Online and Offline Charging feature complies with the following standards:

• 3GPP TS 32.255

• 3GPP TS 32.290

The following table provides details of the application error codes with the corresponding SMF action.

Note

The error code 403 is not configured in the failure handling template. CHARGING_NOT_APPLICABLE (Disable charging) for static and predefined rules, occurs when a proprietary IE “Charging Disabled” in subscriber params is sent in the N4 modification or establishment request. This request is sent to prevent UPF from generating Start of Traffic for the URRs pending for activation. This IE is no longer sent in 2023.01.0 release and beyond. For more information, see the Handling Charging Disable Functionality section.

Gy supports application-level error codes in MSCC-level and Command-level supported by SMF from the OCS server.

MSCC-level Failures

The following tables list the MSCC-level failure codes:

Command-level Failures

The Diameter endpoint pod handles the failure handling configuration after receiving a command-level failure for a Gy message from OCS.

Following are the actions and subactions applicable for Gy:

• Continue

  • FHSubActionEnum_UNKNOWN

  • FHSubActionEnum_DISCARD_TRAFFIC

• Terminate

  • FHSubActionEnum_WITH_TERM_REQUEST

  • FHSubActionEnum_WITHOUT_TERM_REQUEST

You can configure a failure handling profile with the preceding actions and subactions for following failure types that are received in CCA-I, CCA-U, or CCA-T messages:

• Any

• Result-code

  Note	The value ranges from 3000 to 9999.

• Exp-result-code

  Note	The value ranges from 3000 to 9999.

• Local-error

The following table provides details of the result code with the corresponding SMF action.

The SMF performs the following functions when the charging transactions are disabled on N40 interface:

• Deletes the already created Usage Reporting Rules (URR) on N4.

• 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:

• For newly loaded rules, SMF doesn't construct new dynamic URR.

• 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.

• 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.

The SMF supports dynamic change in the ACS configuration during the run time. The ACS Profile configuration defines various parameters for the ACS profile.

The following table lists the SMF and UPF behavioral changes during the dynamic update of ACS configuration in different scenarios.

NOTES:

• If the online report includes service id and the ignore-service-id is not configured in credit control profile, the SMF drops the report.

• If the new online URR contains the same RG as an existing URR, then the SMF drops the usage report.

• If the new offline URR contains the same RG+service ID as an existing URR, the SMF drops the usage report.

• In the same usage report, if the next online URRs include the same RG and the next offline URRs include with the same RG + service ID, the SMF drops the usage report.

The Charging Profile supports dynamically updating the configuration based on the values that you pass during the runtime. The refresh operation of the values takes place considering the following scenarios:

• Configuration reflects in the next encounter to access: If the values are updated while an operation is in-progress, the SMF ignores the new values and continues to use the old values. For example, Limits in Charg-Profile and CC triggers.

• Configuration reflects only on a new session: If the configuration is specific to a session and the session has already considered the values, then the SMF does not consider the new values. For example, PduContext (DB entry). This case indicates that any update to the configuration does not impact the sessions that are already created. For instance, Charging Method in Profile or Charg-Profile in Charging Characteristics.

• Configuration reflects instantly: Configurations immediately consider the dynamic values whenever they are updated. If SMF has already used a configuration and it is later updated, then it uses the latest values.

If a session is created using a Charging Profile, which later gets deleted from the Ops Center, the session might attempt to access the configuration structure of the deleted profile. In such cases, the Smf-Service pod maintains a default profile mapped to the sessions whose profiles are missing.

The Charging Profile is responsible for handling the SMF charging parameters.

The following table lists the configuration parameters with the dynamic configuration change and its impact on the existing sessions.

This section describes the call flow associated with the Pre-emptive Quota Request for the 5G sessions.

Preemptive Quota Request Call Flow -Start of Traffic After Timer Expiry

The SMF maintains the following metrics as part of the Preemptive Quota.

• disc_pdusetup_chf_rg_error: Indicates that the disconnect reason is pegged for pduSession-reject due to preemptive quota validation error.

• disc_pdnsetup_chf_rg_error: Indicates that the disconnect reason is pegged for attach-reject due to preemptive quota validation error.