ETSI GR NFV-EVE 008 V3.1.1 (2017-12)

Network Functions Virtualisation (NFV) Release 3; Charging; Report on Usage Metering and Charging Use Cases and Architectural Study

DGR/NFV-EVE008

General Information

• Status: Published
• Publication Date: 13-Dec-2017
• Technical Committee: NFV EVE - Evolution and Ecosystem
• Current Stage: 12 - Completion
• Due Date: 08-Jan-2018
• Completion Date: 14-Dec-2017

Standards Content (Sample)

ETSI GR NFV-EVE 008 V3.1.1 (2017-12)






GROUP REPORT
Network Function Virtualisation (NFV) Release 3;
Charging;
Report on Usage Metering and Charging Use Cases and
Architectural Study
Disclaimer
The present document has been produced and approved by the Network Functions Virtualisation (NFV) ETSI Industry
Specification Group (ISG) and represents the views of those members who participated in this ISG.
It does not necessarily represent the views of the entire ETSI membership.

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Reference
DGR/NFV-EVE008
Keywords
charging, management, MANO, NFV,
orchestration

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Contents
Intellectual Property Rights . 5
Foreword . 5
Modal verbs terminology . 5
1 Scope . 6
2 References . 6
2.1 Normative references . 6
2.2 Informative references . 6
3 Definitions and abbreviations . 6
3.1 Definitions . 6
3.2 Abbreviations . 7
4 Charging Concepts in NFV . 7
4.1 High Level Expectations . 7
4.2 Resources in NFV . 7
4.3 Chargeable Events . 8
4.3.0 Introduction. 8
4.3.1 Usage Events . 8
4.3.2 Management and Orchestration Events . 8
4.4 Charging Scenarios. 9
5 Use Cases for Usage Metering and Charging Triggers . 9
5.1 General . 9
5.2 Actors, Roles and Domains . 9
5.2.0 introduction . 9
5.2.1 Actors and Business Relationships . 10
5.3 Use Case #1: Charging for NFV Infrastructure as a Service . 11
5.3.1 Actors . 11
5.3.2 Motivation. 11
5.3.3 Summary . 11
5.3.4 Pre-Condition . 12
5.3.5 Begins When . 12
5.3.6 Description . 12
5.3.7 Ends When . 13
5.3.8 Post-Conditions . 13
5.3.9 Exceptions. 13
5.4 Use Case #2: Charge For VNF as a Service . 14
5.4.1 Actors . 14
5.4.2 Motivation. 14
5.4.3 Summary . 14
5.4.4 Pre-Conditions . 14
5.4.5 Begins When . 14
5.4.6 Description . 14
5.4.7 Ends When . 16
5.4.8 Post-Conditions . 16
5.4.9 Exceptions. 16
6 Charging Triggers in an NFV Architectural Framework . 16
6.1 Online Charging Architecture for NFV . 16
6.1.1 Online Charging Architecture for NFV Infrastructure as a Service . 16
6.1.1.0 introduction . 16
6.1.1.2 New Architectural Functional Capabilities . 17
6.1.1.2.1 Charging Quota Tracker . 17
6.1.1.2.2 Charging Trigger Point . 17
6.1.1.3 Direct Approach: Charging Triggering Point to Charging Function . 17
6.1.1.4 Relay Approach: Charging Triggering Point to Charging Function . 18
6.1.1.5 Basic Flow. 19
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6.1.2 Online Charging Architecture for VNF as a Service . 19
6.2 Offline Charging Architecture for NFV . 20
6.2.1 Offline Charging Impact on NFV Architecture . 20
6.2.2 Offline Charging Overlay Architecture . 21
6.2.2.1 Introduction . 21
6.2.2.2 Relayed CDR Delivery Scenario . 21
6.2.2.3 Direct CDR Delivery Scenario . 22
7 Recommendation . 23
Annex A: Authors & contributors . 24
Annex B: Change History . 25
History . 26


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Intellectual Property Rights
Essential patents
IPRs essential or potentially essential to the present document may have been declared to ETSI. The information
pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found
in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in
respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web
server (https://ipr.etsi.org/).
Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee
can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web
server) which are, or may be, or may become, essential to the present document.
Trademarks
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ETSI claims no ownership of these except for any which are indicated as being the property of ETSI, and conveys no
right to use or reproduce any trademark and/or tradename. Mention of those trademarks in the present document does
not constitute an endorsement by ETSI of products, services or organizations associated with those trademarks.
Foreword
This Group Report (GR) has been produced by ETSI Industry Specification Group (ISG) Network Functions
Virtualisation (NFV).
Modal verbs terminology
In the present document "should", "should not", "may", "need not", "will", "will not", "can" and "cannot" are to be
interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of provisions).
"must" and "must not" are NOT allowed in ETSI deliverables except when used in direct citation.

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1 Scope
The present document studies use cases and charging triggers for usage metering of virtualised resources. It proposes
new functional blocks for:
1) the collection and provision of accounting information; and
2) the triggering of charging requests.
The interfaces (and information flows) between the proposed functional blocks and the current NFV Architectural
Framework are part of the study.
The following models have been taken into account: Infrastructure as a Service (IaaS), and VNF as a Service
(VNFaaS).
The present document includes recommendations to either modify existing or new specifications, or both.
While management and orchestration event charging for VNFaasS is part of the present work, usage event charging for
VNFaaS is for further study.
2 References
2.1 Normative references
Normative references are not applicable in the present document.
2.2 Informative references
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
referenced document (including any amendments) applies.
NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee
their long term validity.
The following referenced documents are not necessary for the application of the present document but they assist the
user with regard to a particular subject area.
[i.1] ETSI GS NFV 003: "Network Functions Virtualisation (NFV); Terminology for Main Concepts in
NFV".
[i.2] TM Forum GB989 Impact of SDN/NFV on Charging and Billing R15.5.1 Standard.
3 Definitions and abbreviations
3.1 Definitions
For the purposes of the present document, the terms and definitions given in ETSI GS NFV 003 [i.1] and the following
apply:
resource monitor: agent within the resource that monitors resource usage and reports to Charging Function
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3.2 Abbreviations
For the purposes of the present document, the abbreviations given in ETSI GS NFV 003 [i.1] and the following apply:
BSS Business Support Systems
CDR Call Detail Record
CPU Central Processing Unit
CTP Charging Triggering Point
CTQ Charging Quota Tracker
IaaS Infrastructure as a Service
MANO Management and Orchestration
MNO Mobile Network Operator
MVNO Mobile Virtual Network Operator
OSS Operations Support Systems
QT Quota Tracker
SaaS Software as a Service
VIM Virtualised Infrastructure Manager
4 Charging Concepts in NFV
4.1 High Level Expectations
The high-level expectations for usage metering and charging in NFV are:
• to provide charging information for all charges incurred and requiring settlement between the different roles
(e.g. NFV Infrastructure Provider, VNF Provider, VNF Service Provider, Consumer, etc.);
• to produce sufficient charging information to allow for the following:
- revenue assurance on NFV resource usage;
- fraud detection and mitigation;
- itemized billing for all NFV resource usage by the charged party;
- cost control of NFV resource usage by the charged party;
- to support for a charged party to prepay for NFV resources;
• to support NFV management and orchestration lifecycle events to be mapped to chargeable events;
• to provide real-time usage information.
4.2 Resources in NFV
Below is a list of resources (see clause 3.1 for definitions) that are deemed to be of value for users and operators, and
thus chargeable for consumption of those resources. Hardware resources are not taken into consideration in this clause.
• Virtualisation Layer
• Virtualisation Container
• Virtualised Resources:
- Virtualised CPU including processor and memory
- Virtualised Storage including volumes of storage at either block or file-system level
- Virtual Network including networks, subnets, ports, addresses, links and forwarding rules, for the
purpose of ensuring intra- and inter-VNF connectivity
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• Virtualised Accelerator: An accelerator is a software or hardware component (as stated above hardware
resources are not taken into consideration) intended to improve the NFVI performance or to enable VNFs to
offload some portion of their processing
• VNF Instance: A VNF is considered as a composite resource consisting of a number of Virtualised Compute,
Virtual Network and Virtualised Storage resources
• Network Service Instance
The list of resources and corresponding functional blocks that provide information on resource consumption is
presented in table 1.
Table 1: Mapping resources to functional blocks
Resources in NFV Functional Block
Virtualisation Layer VIM
Virtualisation Container VIM
Virtual Resources VIM
Virtualised Accelerators VIM
VNF Instance NFVO/VNFM
Network Service Instance NFVO

4.3 Chargeable Events
4.3.0 Introduction
Chargeable events are those events that provide Charging and Billing functions with information for rating and billing
purposes. Information can be related to usage of resources or management tasks, such as reservation, instantiation,
scaling, and termination of virtual resources (see clause 4.1).
Therefore, chargeable events can be classified into these two categories:
• Usage Events
• Management and Orchestration Events
4.3.1 Usage Events
In the perspective of NFV MANO Usage Events are those events which provide usage information of NFV resources
(as defined in clause 4.2) in volume/duration or combination of both. For example, a usage event representing the "Peak
or average number of CPU cores used in the last one hour duration by a running VNF instance".
4.3.2 Management and Orchestration Events
"Management and Orchestration" event is a unique action performed by NFV MANO through one or more function or
API calls to achieve the desired output such as (not a complete list):
• Create/Delete VNF Instance
• Create/Delete Virtualisation Container
• Scale VNF Instance
• Create/Delete Network Service Instance
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4.4 Charging Scenarios
The charging scenarios that are relevant to real-time charging of chargeable items:
• Event based charging model is applicable for management and orchestration events and involves an immediate
charging action in a single charge request:
- In this charging scenario, the chargeable item is immediately charged in a single transaction. For
example, instantiation of a VNF.
• Continuous based charging model is applicable for resource consumption and will be based on sessions: In this
charging method, the consumption of data traffic (or CPU time or storage) by virtual resources is the
chargeable item. So examples are volume and the length of time. Continuous charging starts when a resource
consumption begins, for example, at the start of data transfer and ends on resource termination or lack of
funds/credit limit for consumption. Continuous charging flow involves an initial quota request, followed by
one or more intermediate quota requests, and finally followed by a stop charging request.
5 Use Cases for Usage Metering and Charging
Triggers
5.1 General
Table 2 summarizes the two use cases described in this clause for charging triggers.
Table 2: Summary of Use Cases
Use Case # Use Case Name
1 Charging for NFV Infrastructure as a Service
2 Charging for VNF as a Service

Each use case is described using the following items:
• Motivation
• Summary
• Pre-Condition
• Begins When
• Description
• End When
• Post-Condition
• Exception
5.2 Actors, Roles and Domains
5.2.0 introduction
This item introduces the concepts of actors, roles and domains used in the use cases description.
Table 3 provides the list of Actors that have been identified.
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Table 3: Definition of Actors
Actor Definition
NFV Infrastructure Provider The entity that owns the infrastructure and provides
infrastructure as a service
NFV Infrastructure Consumer The user of Infrastructue as a Service
VNF Provider The entity that sells VNF Software
VNF Service Provider The entity that offers VNF as a service to an End User
VNF Consumer The user of VNF as a service
Consumer The user of the service offered
Mobile Network Operator The entity that provides hosted VNFs to its MVNO
customers

5.2.1 Actors and Business Relationships
Many actors are involved in the end-to-end service delivery within an NFV framework.
Aligned with the TM Forum proposal (TMF GB989) [i.2] and through an example, the possible actors and their
business relationships are highlighted.
The example considered in the present document is of an intelligent lighting system for the streets of a city. The system
consists of connected street lights and ensures energy efficiency by offering optimal light intensity. It also reduces
maintenance cost by remotely monitoring street lights.
This light system is offered as a service by a Lighting Service Provider (the company that provides intelligent lighting
system) to the city authority (the consumer of the service).
The Lighting Service Provider connects all the lights with a dedicated virtual packet core network provided as a service
by a Network Service Provider in this example an MVNO. The virtual packet core network consists of multiple VNFs
(for example: vMME and vP-GW) provided as a service by a VNF Service Provider in this example a telecom operator
(MNO).
In this example, the VNF Software Provider (the software vendor) sells the VNF Software (needed for vP-GW and
vMME) to VNF Software users such as the telecom operator.
Finally, the telecom operator uses the virtual resources of a third party NFV Infrastructure for the deployment and
running of the VNF Software. The NFV Infrastructure Provider is a company that provides the resources, as a service,
to NFV Infrastructure Consumers. In this case, the telecom operator is the Infrastructure Consumer.
A graphical representation of the above example is given in figure 1. The arrow pointing up indicates the direction of
the service that is being provided by the entity in the box below. For example, in the Lighting Service Provider box, a
data network connecting lights is consumed as a service by the Lighting Service Provider.
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Figure 1: Illustration of Actors and Business Relationships
5.3 Use Case #1: Charging for NFV Infrastructure as a Service
5.3.1 Actors
The actors related to this use case are:
• NFV Infrastructure Provider
• NFV Infrastructure Consumer
5.3.2 Motivation
IaaS provides a lot of flexibility and cost reduction when compared to the capex model of the traditional data center.
5.3.3 Summary
This use case enables a cost-effective model to offer cloud resources and charge for the usage of resources in real-time.
In this use case:
• The NFV Infrastructure provider and consumer have a Business to Business relationship.
• The NFV Infrastructure provider offers virtual resources (see clause 4.2) as a service to an NFV Infrastructure
consumer.
• The NFV Infrastructure provider charges the NFV Infrastructure consumer for the usage of NFV Infrastructure
resources. This charging can be performed offline or online. Billing operations as well as low balance
notifications, balance recharge and top-up are outside the scope of the present document.
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5.3.4 Pre-Condition
The following pre-conditions apply for this use case:
• NFVI provider and consumer have an agreement in place for a consumption based charging model.
• If credit/cost control is required then a credit limit/threshold is established.
5.3.5 Begins When
The use case begins when the consumer places an order for virtual resources from the IaaS provider. This triggers the
instantiation of the virtual resources by the IaaS Provider. The IaaS provider utilizes its NFV MANO functionality to
instantiate the services.
5.3.6 Description
Off-line charging:
This flow assumes that the consumer of the NFV Infrastructure is charged offline. This means that the consumer
receives a bill at the end of a contractually-defined billing cycle that will trigger the payment. Billing and payment of
the usage is outside the scope of the present document. Figure 2 is a simplified sequence of offline charging information
flows that shows collection of management and usage events:
1) Events are generated for resource usage (usage events) and resource lifecycle operation (management events).
2) Resource monitor periodically (Reporting period) reports Usage Data Records and Management Data Records
that summarize respectively Usage and Management events).
3) Data Records are communicated to Offline Charging Data Collection for aggregation and correlation. Data
Records may need to be enriched with additional information such as correlation IDs (or be rated and have a
cost added at this stage) required for further billing processing.
4) Billing uses the aggregated/correlated event records to charge the consumer at the end of the billing cycle.
5) If the dunning process NFV Infrastructure provider indicates that the resource is suspended, a request from
their BSS is sent to their order management system to suspend the resource.

Figure 2: Usage and Management Data Collection for Offline Charging
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On-line charging:
This flow assumes that the consumer of the NFV Infrastructure has a balance allocated to the usage of the NFV
Infrastructure. Figure 3 is a simplified sequence of online charging interactions:
1) Upon first event of resource usage, the entity that controls the resource and monitors the quota (Quota
Monitor) triggers an online charging request towards charging function in the BSS domain of the NFV
Infrastructure provider.
2) Charging identifies the user of the resource and, in response, sends back a granted quota for consumption.
3) The same entity supervises the resource for the granted quota consumption. When the allocated quota is almost
fully used (configurable threshold % used), the entity reports the usage of the resource and requests for
additional quota from the online charging function.
4) The charging fu
...