6.4 PDU Session related policy information
23.5033GPPPolicy and charging control framework for the 5G System (5GS)Release 18Stage 2TS
The purpose of the PDU Session related policy information is to provide policy and charging control related information that is applicable to a single Monitoring key or the whole PDU Session respectively. The PCF may provide PDU Session related policy information to the SMF together with PCC rules or separately.
Table 6.4-1 includes the PDU Session related policy information.
The differences with table 6.4 and table 6.6 in TS 23.203 [4] are shown, either "none" means that the IE applies in 5GS or "removed" meaning that the IE does not apply in 5GS, this is due to the lack of support in the 5GS for this feature or "modified" meaning that the IE applies with some modifications defined in the IE.
Table 6.4-1: PDU Session related policy information
|
Attribute |
Description |
PCF permitted to modify for dynamically provided information |
Scope |
Differences compared with table 6.4. and 6.6 in TS 23.203 [4] |
|---|---|---|---|---|
|
Charging information |
Defines the containing CHF address and optionally the associated CHF instance ID and CHF set ID. |
No |
PDU Session |
None |
|
Default charging method |
Defines the default charging method for the PDU Session. |
No |
PDU Session |
None |
|
PDU Session with offline charging only |
Indicates that the "online" charging method is never used for PCC rules in the PDU Session. |
No |
PDU Session |
Added |
|
Policy control request trigger |
Defines the event(s) that shall cause a re-request of PCC rules for the PDU Session. |
Yes |
PDU Session |
Explicitly subscribed by invoking Npcf_SMPolicyControl service operation |
|
Authorized QoS per bearer (UE-initiated IP‑CAN bearer activation/modification) |
Defines the authorised QoS for the IP‑CAN bearer (QCI, GBR, MBR). |
Yes |
IP‑CAN bearer |
Removed |
|
Authorized MBR per QCI (network initiated IP‑CAN bearer activation/modification) |
Defines the authorised MBR per QCI. |
Yes |
IP‑CAN session |
Removed |
|
Revalidation time limit |
Defines the time period within which the SMF shall perform a PCC rules request. |
Yes |
PDU Session |
None |
|
PRA Identifier(s) |
Defines the Presence Reporting Area(s) to monitor for the UE with respect to entering/leaving |
Yes |
PDU Session |
None but only applicable to PCF |
|
List(s) of Presence Reporting Area elements (NOTE 14) |
Defines the elements of the Presence Reporting Area(s) |
Yes |
PDU Session |
None but only applicable to PCF |
|
Default NBIFOM access |
The access to be used for all traffic that does not match any existing Routing Rule |
Yes (only at the addition of an access to the IP-CAN session) |
IP-CAN session |
Removed |
|
IP Index (NOTE 11) |
Provided to SMF to assist in determining the IP Address allocation method (e.g. which IP pool to assign from) when a PDU Session requires an IP address – as defined in clause 5.8.2.2.1 of TS 23.501 [2]. |
No |
PDU Session |
Added |
|
Redundant PDU Session |
Indicates whether the PDU Session is a redundant PDU Session |
No |
PDU Session |
New |
|
Explicitly signalled QoS Characteristics (NOTE 1) |
Defines a dynamically assigned 5QI value (from the non-standardized value range) and the associated 5G QoS characteristics as defined in clause 5.7.3 of TS 23.501 [2]. |
No |
PDU Session |
Added |
|
Reflective QoS Timer |
Defines the lifetime of a UE derived QoS rule belonging to the PDU Session. |
No |
PDU Session |
Added |
|
Authorized Session-AMBR (NOTE 2) (NOTE 3) |
Defines the Aggregate Maximum Bit Rate for the Non-GBR QoS Flows of the PDU Session. |
Yes |
PDU Session |
Modified |
|
Authorized default 5QI/ARP (NOTE 3) (NOTE 10) |
Defines the default 5QI and ARP of the QoS Flow associated with the default QoS rule. |
Yes |
PDU Session |
Modified |
|
Time Condition (NOTE 4) |
Defines the time at which the corresponding Subsequent Authorized Session-AMBR or Subsequent Authorized default 5QI/ARP shall be applied. |
No (NOTE 5) |
PDU Session |
Modified |
|
Subsequent Authorized Session-AMBR (NOTE 4) (NOTE 2) |
Defines the Aggregate Maximum Bit Rate for the Non-GBR QoS Flows of the PDU Session when the Time Condition is reached. |
No (NOTE 5) |
PDU Session |
Modified |
|
Subsequent Authorized default 5QI/ARP (NOTE 4) (NOTE 10) |
Defines the default 5QI and ARP when the Time Condition is reached. |
No (NOTE 5) |
PDU Session |
Modified |
|
Usage Monitoring Control related information (NOTE 12) (NOTE 13) |
Defines the information that is required to enable user plane monitoring of resources for individual applications/services, groups of applications/services, for a PDU Session. |
|||
|
Monitoring key |
The PCF uses the monitoring key to group services that share a common allowed usage. |
No |
PDU Session (NOTE 12) |
None |
|
Volume threshold (NOTE 7) |
Defines the traffic volume value after which the SMF shall report usage to the PCF for this monitoring key. |
Yes |
Monitoring key |
None |
|
Time threshold (NOTE 7) |
Defines the resource time usage after which the SMF shall report usage to the PCF. |
Yes |
Monitoring key |
None |
|
Monitoring time |
Defines the time at which the SMF shall reapply the Volume and/or Time Threshold. |
No (NOTE 6) |
Monitoring Key |
None |
|
Subsequent Volume threshold (NOTE 9) |
Defines the traffic volume value after which the SMF shall report usage to the PCF for this Monitoring key for the period after the Monitoring time. |
No (NOTE 6) |
Monitoring Key |
None |
|
Subsequent Time threshold (NOTE 9) |
Defines resource time usage after which the SMF shall report usage to the PCF for this Monitoring key for the period after the Monitoring time. |
No (NOTE 6) |
Monitoring Key |
None |
|
Inactivity Detection Time (NOTE 8) |
Defines the period of time after which the time measurement shall stop, if no packets are received. |
Yes |
Monitoring Key |
None |
|
Ethernet port management related |
||||
|
Port number |
Port number for which Port Management Information Container is provided. |
Yes |
PDU Session |
New |
|
Port Management Information Container |
Includes Ethernet port management information |
Yes |
PDU Session |
New |
|
User plane node Management Information Container |
Includes User plane node management information |
Yes |
New |
|
|
NOTE 1: Multiple Non-standardized QoS Characteristics can be provided by the PCF. Operator configuration is assumed to ensure that the non-standardized 5QI to QoS characteristic relation is unique within the PLMN. NOTE 2: The Authorized Session-AMBR and the Subsequent Authorized Session-AMBR may be provided together with a list of Access Types possibly complemented by RAT types. NOTE 3: There is always an unconditional value for the Authorized Session-AMBR and Authorized default 5QI/ARP available at the SMF. The initial value is received as Subscribed Session-AMBR/Subscribed default 5QI/ARP, and the PCF can overwrite it with these parameters. NOTE 4: The Time Condition and Subsequent Authorized Session-AMBR/ Subsequent Authorized default 5QI/ARP are used together. The PCF may provide up to four instances of them. When multiple instances are provided, the values of the associated Time Condition have to be different. NOTE 5: The PCF may replace all instances that have been provided previously with a new instruction. A previously provided Time Condition and Subsequent Authorized Session-AMBR/ Subsequent Authorized default 5QI/ARP pair cannot be individually modified. NOTE 6: The PCF may replace all instances that have been provided previously with a new instruction. A previously provided Volume threshold/Time threshold and Monitoring Time pair cannot be individually modified. NOTE 7: This attribute is also used by the SMF, e.g. during PDU Session termination, to inform the PCF about the resources that have been consumed by the UE. NOTE 8: This attribute is applicable in presence of Time threshold only. NOTE 9: This attribute is applicable in presence of Monitoring Time only. NOTE 10: The Authorized default 5QI and the Subsequent Authorized default 5QI shall be of Non-GBR Resource Type. NOTE 11: This attribute is applicable only when no IP address/Prefix for the PDU Session is received from the SMF. NOTE 12: A Monitoring Key can either be used to monitor the traffic of a PDU Session, the traffic of a PDU Session per access (for a MA PDU Session) or the traffic of specific SDF(s) in the PCC Rule(s) that share the same Monitoring Key. NOTE 13: For a MA PDU Session, the PDU Session level Usage Monitoring shall be possible per access (i.e. 3GPP and/or Non-3GPP) and irrespective of the access. NOTE 14: The list of PRA elements shall be a short list of elements. |
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Upon the initial interaction with the SMF, the PCF may provide the following attributes to the SMF:
The Charging information contains addresses of the CHF that manages charging for the PDU Session and optionally the associated CHF instance ID and CHF set ID (see clause 6.3.1.0 of TS 23.501 [2]). If received, the SMF shall apply it as defined in clause 6.3.11 of TS 23.501 [2].
The Default charging method indicates what charging method shall be used in the PDU Session for every PCC rule where the charging method identifier is omitted, including predefined PCC rules that are activated by the SMF. If received by the SMF, it supersedes the Default charging method in the charging characteristics profile.
The PDU Session with offline charging only can be assigned to a PDU Session by the PCF to indicate that the online charging method is never set for any of the PCC Rules activated during the lifetime of the PDU Session nor provided as Default charging method.
NOTE 1: If this parameter is provided by the PCF or configured in the SMF charging characteristics the SMF can use the Nchf_OfflineOnlyCharging service instead of the Nchf_ConvergedCharging service for a PDU Session as defined in TS 32.255 [21].
NOTE 2: When the "PDU Session with offline charging only" indication is provisioned by the PCF, the PCF can set the charging method for a PCC rule within this PDU Session to either "offline" or "neither".
The IP Index indicates the IP Address/Prefix allocation method which is used by the SMF for IP Address/Prefix allocation during PDU Session Establishment procedure as defined in clause 5.8.2.2.1 of TS 23.501 [2].
Upon every interaction with the SMF, the PCF may provide the following attributes to the SMF:
The Revalidation time limit defines the time period within which the SMF shall trigger a request for PCC rules for an established PDU Session.
The Reflective QoS Timer defines the lifetime of a UE derived QoS rule belonging to the PDU Session. It is used in the UE as defined in clause 5.7.5.3 of TS 23.501 [2].
NOTE 3: The Reflective QoS Timer that is sent to the UE has to be in alignment with the corresponding timer configured in the UPF (defined in clause 5.7.5.3 of TS 23.501 [2]).
The Authorized Session-AMBR defines the UL/DL Aggregate Maximum Bit Rate for the Non-GBR QoS Flows of the PDU Session, which is enforced in the UPF as defined in clause 5.7.1 of TS 23.501 [2]. The PCF may provide the Authorized Session-AMBR in every interaction with the SMF. When the SMF receives it from the PDU Session policy, it is provided to the UPF over N4 interface for the enforcement.
The Authorized default 5QI/ARP defines the 5QI and ARP values of the QoS Flow associated with the default QoS rule as described in clause 6.2.2.4. The SMF applies the Authorized default 5QI/ARP also for the QoS Flow binding as described in clause 6.1.3.2.4.
The Time Condition and Subsequent Authorized Session-AMBR / Subsequent Authorized default 5QI/ARP are used together and up to four instances with different values of the Time Condition parameter may be provided by the PCF. Time Condition indicates that the associated Subsequent Authorized Session-AMBR/ Subsequent Authorized default 5QI/ARP is only applied when the time defined by this attribute is met. When the SMF receives a Time Condition and Subsequent Authorized Session-AMBR/ Subsequent Authorized default 5QI/ARP pair, it stores it locally. The SMF shall discard any previously received Subsequent Authorized Session-AMBR / Subsequent Authorized default 5QI/ARP instances on explicit instruction as well as whenever the PCF provides a new instruction for one or more Subsequent Authorized Session-AMBR / Subsequent Authorized default 5QI/ARP. When the time defined by the Time Condition parameter is reached, the SMF shall apply (or instruct the UPF to apply) Subsequent Authorized Session-AMBR/ Subsequent Authorized default 5QI/ARP.
NOTE 4: In order to reduce the risk for signalling overload, the PCF should avoid simultaneous provisioning of the Subsequent Authorized Session-AMBR/ Subsequent Authorized default 5QI/ARP for many UEs (e.g. by spreading over time).
NOTE 5: In order to provide further Subsequent Authorized Session-AMBR/ Subsequent Authorized default 5QI/ARP in a timely fashion the PCF can use its own clock to issue the desired changes or use the Revalidation time limit parameter to trigger an SMF request for a policy decision.
NOTE 6: For services that depend on specific Session-AMBR and/or default 5QI/ARP (e.g. MPS session) the PCF is responsible to ensure that no Subsequent Authorized Session-AMBR or Subsequent Authorized default 5QI/ARP interfere with the service, e.g. by removing the Subsequent Authorized Session-AMBR or Subsequent Authorized default 5QI/ARP before the respective change time is reached.
The Monitoring Key is the reference to a resource threshold. Any number of PCC Rules may share the same monitoring key value. The monitoring key values for each service shall be operator configurable.
It shall also be possible for an operator to use the Monitoring Key parameter to indicate usage monitoring on an PDU Session level or, in the case of an MA PDU Session, to indicate usage monitoring on PDU Session level for the 3GPP access and/or the Non-3GPP access.
Usage monitoring on PDU Session level is active when a PDU Session is active when a Monitoring Key for the PDU Session and a corresponding volume and/or time threshold value have been provided to the SMF. Usage monitoring on Monitoring key level is active when a volume and/or time threshold has been provided for a Monitoring Key to the SMF and there is at least one PCC rule active for the PDU Session that is associated with that Monitoring Key.
The Volume threshold indicates the overall user traffic volume value after which the SMF shall report the Usage threshold reached trigger to the PCF.
The Time threshold indicates the overall resource time usage after which the SMF shall report the Usage threshold reached trigger to the PCF.
The Monitoring time indicates the time at which the SMF shall store the accumulated usage information.
The Subsequent Volume threshold indicates the overall user traffic volume value measured after Monitoring time, after which the SMF shall report the Usage threshold reached trigger to the PCF.
The Subsequent Time threshold indicates the overall resource time usage measured after Monitoring time, after which the SMF shall report the Usage threshold reached trigger to the PCF.
The Inactivity Detection Time indicates the period of time after which the time measurement shall stop, if no packets are received during that time period.
The Port Management Information Container carries Ethernet port management information for an Ethernet port located in DS-TT or NW-TT. The port for which the container is provided is identified by the port number.
The User plane node Management Information Container carries User plane node management information for a 5GS Bridge.