Content for TS 28.500 Word version: 18.0.0

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5.4 High-level use cases 5.4.1 FM use cases 5.4.2 CM use cases 5.4.3 PM use cases 5.4.4 LCM use cases

5.4 High-level use cases p. 12

5.4.1 FM use cases p. 12

5.4.1.1 Use case of VNF Healing triggered by 3GPP management system p. 12

Use case stage	Evolution/Specification	<<Uses>> Related use
Goal	To execute VNF Healing for a virtualized network function.
Actors and Roles	3GPP management system requests to execute the VNF Healing.
Telecom resources	3GPP management system. NFV-MANO. VNF.
Assumptions	3GPP management system is subscribed to VNF lifecycle change notifications from the NFV-MANO.
Pre-conditions	The subject VNF instance is not being healed at the moment.
Begins when	A faulty virtualization-specific aspect of the VNF has been notified to 3GPP management system.
Step 1 (M)	3GPP management system determines that VNF Healing of the VNF is needed.
Step 2 (M)	3GPP management system requests the NFV-MANO to execute the VNF Healing based on the information in the request.
Step 3 (M)	NFV-MANO notifies 3GPP management system about the end and the result of the VNF Healing execution.
Ends when	All the steps identified above are successfully completed.
Exceptions	The VNF Healing procedure in step 2 fails.
Post-conditions	The faulty virtualization-specific aspect of the VNF is recovered.
Traceability	REQ-NFV_LCM_SYS-CON-11

5.4.1.2 Use case of virtualization-specific aspect failure detection and notification by NFV-MANO p. 13

Use case stage	Evolution/Specification	<<Uses>> Related use
Goal	To notify the 3GPP management system of a virtualization-specific failure of a virtualized network functions.
Actors and Roles	3GPP management system receives the fault report. NFV-MANO notifies about VNF-related virtualization faults.
Telecom resources	3GPP management system. NFV-MANO. VNF.
Assumptions	3GPP management system is subscribed to VNF-related virtualization-specific fault reports from the NFV-MANO.
Pre-conditions	N/A
Begins when	A virtualization-specific fault affecting the VNF is notified to NFV-MANO.
Step 1 (M)	NFV-MANO creates VNF-related virtualization fault report about the faulty virtualization-specific aspect.
Step 2 (M)	NFV-MANO sends the VNF-related virtualization fault report to the 3GPP management system.
Ends when	All the steps identified above are successfully completed.
Exceptions
Post-conditions	The 3GPP management system is notified about the virtualization-specific failure of the subject VNF.
Traceability	REQ-NFV_FM_SYS-CON-7

5.4.1.3 Use case of alarms correlation by 3GPP management system p. 13

Use case stage	Evolution/Specification	<<Uses>> Related use
Goal	To correlate VNF alarms in a mobile network that includes virtualized network functions.
Actors and Roles	3GPP management system correlates VNF alarms.
Telecom resources	NFV-MANO VNF NFVI
Assumptions	3GPP management system has the alarm correlation function. 3GPP management system is subscribed to VNF-related virtualized resource fault reports from the NFV-MANO. The virtualized resource failure affects the corresponding VNF.
Pre-conditions
Begins when	NFV-MANO detects the virtualized resource fault affecting the VNF.
Step 1 (M)	NFV-MANO creates VNF fault report related to virtualized resource and sends it to the 3GPP management system.
Step 2 (M)	3GPP management system receives the VNF fault report related to virtualized resource. 3GPP management system also receives VNF application alarm(s) of a faulty NE.
Step 3 (M)	3GPP management system implements alarm correlation based on the virtualized resource alarm(s) from NFV-MANO and VNF application alarm(s) from NE.
Step 4 (M)	3GPP management system generates the final VNF application fault report including the above correlated alarm(s).
Ends when	Ends when all mandatory steps identified above are successfully completed or when an exception occurs.
Exceptions	One of the steps identified above fails.
Post-conditions	3GPP management system will process the alarm(s) based on the final fault report.
Traceability	REQ-NFV_FM_SYS-CON-2, REQ-NFV_FM_SYS-CON-7

5.4.2 CM use cases p. 13

5.4.2.1 Use case of adding a MO related to a VNF p. 14

Use case stage	Evolution/Specification	<<Uses>> Related use
Goal	To add a MO related to a VNF.
Actors and Roles	3GPP management system.
Telecom resources	3GPP management system. VNF.
Assumptions
Pre conditions	N/A
Begins when	Operator has decided to add a MO related to the VNF.
Step 1 (M)	3GPP management system creates the MO related to the VNF. Note: the MO creation operation here means Basic CM IRP.
Ends when	Ends when all mandatory steps identified above are successfully completed or when an exception occurs.
Exceptions	One of the steps identified above fails.
Post Conditions	The MO is available for 3GPP management system.
Traceability	REQ-NFV_CM_SYS-CON-2

5.4.2.2 Use case of associating the MO with a certain VNF instance p. 14

Use case stage	Evolution/Specification	<<Uses>> Related use
Goal	To associate the MO with a certain VNF instance.
Actors and Roles	3GPP management system.
Telecom resources	3GPP management system. VNF.
Assumptions
Pre conditions	3GPP management system has known the VNF instance identifier.
Begins when	Operator has decided to associate the MO with a certain VNF instance.
Step 1 (M)	3GPP management system associates the MO with a certain VNF instance. Note: The associating operation may happen during the process of creation of MO or after it.
Ends when	Ends when all mandatory steps identified above are successfully completed or when an exception occurs.
Exceptions	One of the steps identified above fails.
Post Conditions	The MO is associated with The VNF instance. And the MO can be managed by 3GPP management system.
Traceability	REQ-NFV_CM_SYS-CON-2

5.4.2.3 Use case of configuring the VNF by 3GPP management system p. 15

Use case stage	Evolution/Specification	<<Uses>> Related use
Goal	To configure the VNF with MO attributes.
Actors and Roles	3GPP management system.
Telecom resources	3GPP management system. VNF.
Assumptions
Pre conditions	3GPP management system has added a MO related to the VNF.
Begins when	Operator has decided to configure the VNF.
Step 1 (M)	3GPP management system configures the VNF with MO attributes.
Ends when	Ends when all mandatory steps identified above are successfully completed or when an exception occurs.
Exceptions	One of the steps identified above fails.
Post Conditions	The VNF has been configured by 3GPP management system.
Traceability	REQ-NFV_CM_SYS-CON-2

5.4.2.4 Use case of removing the MO of a VNF from managed nodes p. 15

Use case stage	Evolution/Specification	<<Uses>> Related use
Goal	To remove the MO of a VNF from managed nodes.
Actors and Roles	3GPP management system.
Telecom resources	3GPP management system. VNF.
Assumptions
Pre conditions	3GPP services provided by the VNF instance have been released. NFV-MANO has already terminated the VNF instance.
Begins when	Operator has decided to remove the MO of the VNF instance from managed nodes.
Step 1 (M)	3GPP management system removes the MO of the VNF instance.
Ends when	Ends when all mandatory steps identified above are successfully completed or when an exception occurs.
Exceptions	One of the steps identified above fails.
Post Conditions	The MO of the VNF instance has been removed from managed nodes.
Traceability	REQ-NFV_CM_SYS-CON-2

5.4.2.5 Modify non-application information and configuration of a VNF instance managed by NFV-MANO p. 16

Use case stage	Evolution/Specification	<<Uses>> Related use
Goal	To modify by 3GPP management system non-application information and configuration of a subject VNF instance. Such an information and configuration is managed by NFV-MANO (see clause 9.4.2 in ETSI GS NFV-IFA 008 [10]); for instance, VNF instance name and meta data.
Actors and Roles	3GPP management system requests the modification of VNF instance information and/or configuration.
Telecom resources	3GPP management system. NFV-MANO
Assumptions	N/A
Pre-conditions	N/A
Begins when	3GPP management system determines to modify certain non-application information and/or configuration held by NFV-MANO of a subject VNF instance.
Step 1 (M)	3GPP management system sends a request to NFV-MANO to modify the non-application information and/or configuration about the subject VNF instance (see related interface requirements in clause 5.2.1.1 in ETSI GS NFV-IFA 008 [10] and in clause 5.3.2 in ETSI GS NFV-IFA 013 [9]).
Step 2 (M)	NFV-MANO modifies the requested information and/or configuration about the subject VNF instance.
Ends when	Ends when all steps identified above are completed or when an exception occurs.
Exceptions	One of the steps identified above fails.
Post-conditions	The non-application information and/or configuration of the subject VNF instance managed by NFV-MANO instance has been modified.
Traceability	REQ-NFV_CM_SYS-CON-5

5.4.2.6 Retrieve non-application information of a VNF instance managed by NFV-MANO p. 16

Use case stage	Evolution/Specification	<<Uses>> Related use
Goal	To retrieve by 3GPP management system from NFV-MANO non-application information of a subject VNF instance. Such information about a subject VNF instance is information managed by NFV-MANO (see clause 9.4.2 in ETSI GS NFV-IFA 008 [10]).
Actors and Roles	3GPP management system queries the VNF instance information.
Telecom resources	3GPP management system. NFV-MANO
Assumptions	N/A
Pre-conditions	N/A
Begins when	3GPP management system determines to retrieve certain information about a subject VNF instance that is managed by NFV-MANO.
Step 1 (M)	3GPP management system sends a request to NFV-MANO querying the needed non-application information about the subject VNF instance (see related interface requirements in clause 5.2.1.1 in ETSI GS NFV-IFA 008 [10] and in clause 5.3.2 in ETSI GS NFV-IFA 013 [9]).
Step 2 (M)	NFV-MANO returns to 3GPP management system the information requested about the subject VNF instance.
Ends when	Ends when all steps identified above are completed or when an exception occurs.
Exceptions	One of the steps identified above fails.
Post-conditions	3GPP management system has the non-application information about the subject VNF instance managed by NFV-MANO.
Traceability	REQ-NFV_CM_SYS-CON-6

5.4.3 PM use cases p. 17

5.4.3.1 Use case of mitigating the VNF performance bottleneck p. 17

Use case stage	Evolution/Specification	<<Uses>> Related use
Goal	To mitigate the VNF performance bottleneck.
Actors and Roles	3GPP management system.
Telecom resources	NFV-MANO VNF
Assumptions	3GPP management system is set up to collect VNF performance measurements and NFV-MANO is set up to collect VNF performance measurements related to virtualized resource.
Pre-conditions	VNF application threshold crossing trigger and VNF-related virtualized resource threshold crossing trigger have been set up by corresponding system(s) (i.e. 3GPP management system or NFV-MANO system).
Begins when	The VNF performance measurement report(s), VNF performance measurement report(s) related to virtualized resource or the thresholds crossing alarm(s) are generated.
Step 1 (M)	3GPP management system receives the VNF performance measurement report(s), VNF performance measurement report(s) related to virtualized resource or the thresholds crossing alarm(s).
Step 2 (M)	3GPP management system decides to optimize the VNF performance and mitigate the VNF performance bottleneck.
Step 3 (M)	3GPP management system requests VNF LCM operation (e.g. expansion) towards NFV-MANO.
Ends when	NFV-MANO executes the VNF LCM operation.
Exceptions	One of the steps identified above fails.
Post-conditions	The VNF performance bottleneck has been mitigated after the VNF LCM operation.
Traceability	REQ-NFV_PM_SYS-CON-3

5.4.3.2 Use case for collection of VNF PM data related to virtualized resource from NFV-MANO p. 17

Use case stage	Evolution/Specification	<<Uses>> Related use
Goal	3GPP management system gets the VNF PM data related to virtualized resource.
Actors and Roles	3GPP management system
Telecom resources	3GPP management system NFV-MANO
Assumptions	NFV-MANO is set up to collect VNF-related virtualized resource performance measurements and generates the report of VNF PM data related to virtualized resource.
Pre-conditions	The collection mechanism for VNF PM data related to virtualized resource has been established both at 3GPP management system and NFV-MANO.
Begins when	3GPP management system needs the VNF PM data which are related to virtualized resource and sets the PM job for them. And VNF PM data related to virtualized resource is generatedby NFV-MANO.
Step 1 (M)	NFV-MANO provides the VNF PM data related to virtualized resource to 3GPP manamement system.
Step 2 (M)	3GPP management system receives the VNF PM data related to virtualized resource.
Ends when	Ends when all mandatory steps identified above are successfully completed.
Exceptions	None.
Post-conditions	3GPP management system has the performance data desired.
Traceability	REQ-NFV_PM_SYS-CON-2, REQ-NFV_PM_SYS-CON-4

5.4.4 LCM use cases p. 18

5.4.4.1 Use case of NS instance Deployment p. 18

Use case stage	Evolution/Specification	<<Uses>> Related use
Goal	To deploy a NS instance in a mobile network that includes virtualized network functions
Actors and Roles	3GPP management system (NM part).
Telecom resources	NFV-MANO.
Assumptions	Existing VNF instance(s) could be used by the new NS instance. Any NSD may be reused for instantiating multiple NS instances. 3GPP management system is subscribed to receive NS lifecycle change notifications.
Pre-conditions	The NSD to be used for the NS instantiation has been on-boarded on NFV-MANO.
Begins when	3GPP management system determines that a new NS instance is to be instantiated.
Step 1 (M)	3GPP management system determines the type and capacity of a NS instance, and sets NS instantiation request with proper parameters.
Step 2 (M)	3GPP management system sends NS instantiation request to NFV-MANO.
Step 3 (M)	NFV-MANO instantiates the NS instance based on request from 3GPP management system.
Ends when	3GPP management system receives notification from NFV-MANO that a new NS instance is instantiated.
Exceptions	One of the steps identified above fails.
Post-conditions	A new NS instance is ready for service.
Traceability	REQ-NFV_LCM_SYS-CON-1, REQ-NFV_LCM_SYS-CON-5, REQ-NFV_LCM_SYS-CON-17

5.4.4.2 Use case of updating an NS instance to a different NSD version p. 19

Use case stage	Evolution/Specification	<<Uses>> Related use
Goal	The network operator through 3GPP management system can decide when and has the capacity to update the NS instance (created based on an NSD of certain version) to correspond to a different NSD version.
Actors and Roles	3GPP management system.
Telecom resources	NFV-MANO
Assumptions
Pre-conditions	The information, to update an existing NS instance, to correspond to a different NSD version exists. The different NSD version has been on-boarded on NFV-MANO.
Begins when	3GPP management system needs to update an existing NS instance (created based on an NSD of certain version) to correspond to the different NSD version.
Step 1 (M)	3GPP management system requests to NFV-MANO to update the NS instance to correspond to the different NSD version, instructing NFV-MANO not to synchronize automatically the NS instance to the different NSD version.
Step 2 (M)	NFV-MANO executes the NS update operation and acknowledges to 3GPP management system the successful update of the NS instance to correspond to the different NSD version.
Step 3 (M)	3GPP management system requests to NFV-MANO to update the NS instance based on the different NSD version.
Step 4 (M)	NFV-MANO executes the NS update operation and acknowledges to 3GPP management system the successful NS instance update.
Ends when	Ends when all steps identified above are completed or when an exception occurs.
Exceptions	One of the steps identified above fails.
Post-conditions	The NS instance has been updated to correspond to the different NSD version.
Traceability	REQ-NFV_LCM_SYS-CON-1, REQ-NFV_LCM_SYS-CON-7

5.4.4.3 Use cases of NE deployment in the context of NFV p. 20

5.4.4.3.1 Use case of NE deployment in the scenario of Managed Object(s) creation is after the VNF instantiation p. 20

Use case stage	Evolution/Specification	<<Uses>> Related use
Goal	To deploy a NE in a mobile network that includes virtualized network functions
Actors and Roles	3GPP management system (NM, EM) creates and configures Managed Object(s) for the corresponding VNF instance. NFV-MANO system instantiates VNF instance according to the request from 3GPP management system
Telecom resources	3GPP management system NFV-MANO system
Assumptions	3GPP management system and NFV-MANO system are in operational status.
Pre-conditions	Operator has decided the type and capacity of the NE to be deployed.
Begins when	Operator decides to deploy a new NE.
Step 1 (M)	3GPP management system sends the VNF instantiation request to NFV-MANO system.
Step 2 (M)	NFV-MANO system instantiates the VNF instance.
Step 3 (M)	3GPP management system receives the result of VNF instantiation from NFV-MANO system.
Step 4 (M)	3GPP management system creates Managed Object(s) for the instantiated VNF instance when needed.
Step 5 (M)	3GPP management system configures the VNF instance with Managed Object attributes when needed.
Ends when	Ends when all mandatory steps identified above are successfully completed or when an exception occurs.
Exceptions	One of the steps identified above fails.
Post-conditions	The new NE is deployed and ready for providing service.
Traceability	TBD

5.4.4.4 Use case for notifications about VNF lifecycle changes p. 20

Use case stage	Evolution/Specification	<<Uses>> Related use
Goal	To monitor by 3GPP management system of lifecycle changes on VNF instances.
Actors and Roles	3GPP management system subscribes to and receives VNF lifecycle change notifications.
Telecom resources	3GPP management system. NFV-MANO system. VNF.
Assumptions
Pre-conditions	NFV-MANO system is running.
Begins when	3GPP management system determines to monitor VNF lifecycle changes on a managed VNF instance.
Step 1 (M)	3GPP management system requests a subscription to NFV-MANO system to receive VNF lifecycle change notifications regarding a managed VNF instance.
Step 2 (M)	NFV-MANO system creates a subscription and acknowledges the subscription to 3GPP management system.
Step 3 (M)	When managed VNF instance has a lifecycle change, NFV-MANO system creates and sends VNF lifecycle change notification including information to identify the VNF instance subject to lifecycle change, the type of procedure, and whether it is the start or end of the procedure.
Ends when	3GPP management system unsubscribes to VNF lifecycle change notifications regarding the managed VNF instance.
Exceptions
Post-conditions	The 3GPP management system has information about VNF lifecycle changes of the managed VNF instance.
Traceability	REQ-NFV_LCM_SYS-CON-9, REQ-NFV_LCM_SYS-CON-15

5.4.4.5 Use case of VNF instance scaling through operation request by 3GPP management system p. 22

Use case stage	Evolution/Specification	<<Uses>> Related use
Goal	To expand/contract a VNF instance by scaling the VNF instance.
Actors and Roles	3GPP management system detects the need for scaling and sends the VNF scaling request.
Telecom resources	3GPP management system. NFV-MANO system. VNF. NFVI.
Assumptions	3GPP management system is subscribed to VNF lifecycle change notifications from the NFV-MANO system.
Pre-conditions	The subject VNF instance is not being scaled at the moment. VNFM (part of NFV-MANO system) does not have any auto-scaling scripts or the policy for auto-scaling is not in use or active. Note: Determining whether "the subject VNF instance is not being scaled" can be done through the lifecycle change notification as described in clause 5.4.4.4 of TS 28.500. Determining whether "there is no auto-scaling scripts or policy for auto-scaling is not used or active" can be done by sending a query request for the subject VNF instance from the 3GPP management system to the NFV-MANO system as described in clause 6.4.7 of TS 28.510.	"Use case for notifications about VNF lifecycle changes" (see clause 5.4.4.4 of TS 28.500) "Retrieve VNF instance information from VNFM by EM" (see clause 6.4.7 in TS 28.510)
Begins when	3GPP management system detected the need to scale and have determined the scaling action (expand/contract).
Step 1 (M)	3GPP management system sends to NFV-MANO system a request to expand/contract the managed VNF instance.
Step 2 (M)	NFV-MANO system executes the scaling of the VNF instance.
Step 3 (M)	NFV-MANO system notifies 3GPP management system about the end of the VNF scaling execution.
Ends when	All the steps identified above are successfully completed.
Exceptions
Post-conditions	The VNF instance has been scaled (expansion/contraction).
Traceability	REQ-NFV_LCM_SYS-CON-4, REQ-NFV_LCM_SYS-CON-9, REQ-NFV_LCM_SYS-CON-10

5.4.4.6 Use case of enabling/disabling the auto-scaling of the corresponding VNF instance(s) p. 23

Use case stage	Evolution/Specification	<<Uses>> Related use
Goal	According to the management requirement, operators need to enable/disable the auto-scaling of a VNF instance(s).
Actors and Roles	3GPP management system requests the enabling/disabling the auto-scaling of the corresponding VNF instance(s) for an NE.
Telecom resources	NFV-MANO, VNF
Assumptions	The auto-scaling, which means automatic procedure controlled and executed by NFV-MANO to scale the capacity of a VNF instance.
Pre-conditions
Begins when	The operator decides to enable/disable the auto-scaling of the corresponding VNF instance(s) for an NE.
Step 1 (M)	3GPP management system requests NFV-MANO to enable/disable the auto-scaling of the corresponding VNF instance(s) for the subject NE.
Step 2 (M)	NFV-MANO enables/disables the auto-scaling function towards the specific VNF instance(s).
Ends when	Ends when all steps identified above are completed or when an exception occurs.
Exceptions	One of the steps identified above fails.
Post-conditions	The auto-scaling of the corresponding VNF instance(s) for an NE is enabled/disabled.
Traceability	REQ-NFV_LCM_SYS-CON-13

5.4.4.7 Determination on the termination of the corresponding VNF instance(s) p. 23

Use case stage	Evolution/Specification	<<Uses>> Related use
Goal	The operator determines to terminate a VNF instance(s) based on the operator's needs or the pre-configuration policy.
Actors and Roles	3GPP management system requests the termination of the corresponding VNF instance(s) for an NE.
Telecom resources	NFV-MANO, VNF
Assumptions	The operator makes the decision to terminate the corresponding VNF instance(s) for an NE.
Pre-conditions
Begins when	3GPP management system completes the preparation for the VNF termination.
Step 1 (M)	3GPP management system requests NFV-MANO to terminate the corresponding VNF instance(s).
Step 2 (M)	NFV-MANO completes the termination operation towards the specific VNF instance(s).
Ends when	Ends when all steps identified above are completed or when an exception occurs.
Exceptions	One of the steps identified above fails.
Post-conditions
Traceability	REQ-NFV_LCM_SYS-CON-12