ETSI GS NFV-REL 006 V3.1.1 (2018-02)

Network Functions Virtualisation (NFV) Release 3; Reliability; Maintaining Service Availability and Continuity Upon Software Modification

DGS/NFV-REL006

General Information

• Status: Published
• Publication Date: 12-Feb-2018
• Technical Committee: NFV REL - Reliability & Availability
• Current Stage: 12 - Completion
• Due Date: 21-Feb-2018
• Completion Date: 13-Feb-2018

Standards Content (Sample)

ETSI GS NFV-REL 006 V3.1.1 (2018-02)






GROUP SPECIFICATION
Network Functions Virtualisation (NFV) Release 3;
Reliability;
Maintaining Service Availability and
Continuity Upon Software Modification
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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2 ETSI GS NFV-REL 006 V3.1.1 (2018-02)



Reference
DGS/NFV-REL006
Keywords
NFV, reliability, software

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3 ETSI GS NFV-REL 006 V3.1.1 (2018-02)
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 . 7
3 Definitions and abbreviations . 7
3.1 Definitions . 7
3.2 Abbreviations . 8
4 Overview . 8
5 NFV Software . 9
5.1 Types of NFV Software . 9
5.1.1 Introduction. 9
5.1.2 VNF Domain Software . 10
5.1.3 MANO Domain Software . 10
5.1.4 NFVI Software . 11
5.2 Software Modification Implications . 11
6 Software Modification Process . 12
6.1 Overview . 12
6.2 The Overall Software Modification Process. 12
6.3 Applicability for Software Types . 15
6.3.1 Network Services/VNFs . 15
6.3.1.1 VNF Software Modification Scenarios . 15
6.3.1.2 VNF Software Modification Requirements . 16
6.3.2 Management and Orchestration Software Modification Process . 17
6.3.2.1 Introduction . 17
6.3.2.2 Addition of Management and Orchestration Component - An Overview . 18
6.3.2.3 Critical Assumptions for Reliability . 18
6.3.2.4 Requirements . 19
6.3.3 NFVI Software . 19
6.3.3.1 Introduction . 19
6.3.3.2 Software Modification Precedence . 20
6.3.3.3 Coordination of NFVI Software Modifications . 20
6.3.3.4 NFVI Resource Software Modification . 21
6.3.3.5 NFVI Software Modification Requirements . 22
6.4 Exception Handling of Problems during Software Modification Process . 22
6.5 Test Process - High Level Overview . 24
6.5.1 Introduction. 24
6.5.2 Pre-deployment Testing for VNFs . 25
6.5.3 Pre-deployment Testing for NFVI Elements . 26
Annex A (informative): Analysis of VNF Software Modifications . 28
A.1 Introduction . 28
A.2 Different VNF design and deployment patterns . 28
A.3 Use Case 1: Stateless VNF upgrade . 28
A.4 Use Case 2: Stateful VNF upgrade . 29
A.4.1 Deployment option 1: Stateful VNF with active-standby redundancy . 29
A.4.2 Deployment option 2: Simultaneous operation of the old and new software version instances . 29
A.4.3 Deployment option 3: Stateful VNF with load sharing . 30
A.4.4 Deployment option 4: Stateful VNF with an internal resiliency mechanism . 31
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4 ETSI GS NFV-REL 006 V3.1.1 (2018-02)
A.5 Use Case 3: VNF software update . 32
A.6 Use Case 4: NS update with simultaneous software upgrade of multiple VNF instances . 33
A.7 Summary . 33
Annex B (informative): Potential solutions for VNF software modification . 35
B.1 Introduction . 35
B.2 Alternative Solutions for Supporting VNF Software Modification with Existing LCM Operations . 35
B.2.1 General . 35
B.2.2 Alternative Method #1 . 35
B.2.3 Alternative Method #2 . 36
B.2.3.1 General . 36
B.2.3.2 Variant A . 36
B.2.3.3 Variant B . 36
B.3 Alternative Solutions for Supporting VNF Software Modification with New LCM Operations . 37
B.3.0 Introduction . 37
B.3.1 Overview of the VNF Instantiation Operation . 38
B.3.2 VNF Software Modification Initiated from the OSS/BSS. 38
B.3.3 VNF Software Modification Initiated from the EM . 43
Annex C (informative): NFVI Software Modification Flows . 45
C.1 Exemplary Coordination of NFVI Software Modifications . 45
C.2 Illustrative Example of NFVI Resource Software Modification . 47
Annex D (informative): Authors & Contributors . 49
History . 50


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Intellectual Property Rights
Essential patents
IPRs essential or potentially essential to normative deliverables 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
The present document may include trademarks and/or tradenames which are asserted and/or registered by their owners.
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 Specification (GS) has been produced by ETSI Industry Specification Group (ISG) Network Functions
Virtualisation (NFV).
Modal verbs terminology
In the present document "shall", "shall not", "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 specifies requirements for the purpose of Software Modifications, such that NFV service
availability and continuity is maintained. All types of software related to Network Function Virtualisation (NFV) - e.g.
Virtual Network Functions (VNF), Management and Orchestration (MANO) and Network Function Virtualisation
Infrastructure (NFVI) as well as required controlling and supporting functionality will be addressed. Where applicable,
external specifications may be referenced to avoid duplication of work. The present document contains normative
provisions.
2 References
2.1 Normative 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.
Referenced documents which are not found to be publicly available in the expected location might be found at
https://docbox.etsi.org/Reference/.
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 necessary for the application of the present document.
[1] ETSI GS NFV 002 (V1.2.1): "Network Functions Virtualisation (NFV); Architectural
Framework".
[2] ETSI GS NFV-MAN 001 (V1.1.1): "Network Functions Virtualisation (NFV); Management and
Orchestration".
[3] ETSI GS NFV-SWA 001 (V1.1.1): "Network Functions Virtualisation (NFV); Virtual Network
Functions Architecture".
[4] ETSI GS NFV-IFA 011 (V2.1.1): "Network Functions Virtualisation (NFV); Management and
Orchestration; VNF Packaging Specification".
[5] ETSI GS NFV-IFA 013 (V2.1.1): "Network Functions Virtualisation (NFV); Management and
Orchestration; Os-Ma-Nfvo reference point - Interface and Information Model Specification".
[6] ETSI GS NFV-IFA 007 (V2.1.1): "Network Functions Virtualisation (NFV); Management and
Orchestration; Or-Vnfm reference point - Interface and Information Model Specification".
[7] ETSI GS NFV-IFA 005 (V2.1.1): "Network Functions Virtualisation (NFV); Management and
Orchestration; Or-Vi reference point - Interface and Information Model Specification".
[8] ETSI GS NFV-IFA 008 (V2.1.1): "Network Functions Virtualisation (NFV); Management and
Orchestration; Ve-Vnfm reference point - Interface and Information Model Specification".
[9] ETSI GS NFV-SOL 004 (V2.3.1): "Network Functions Virtualisation (NFV) Release 2; Protocols
and Data Models; VNF Package specification".
[10] ETSI GS NFV-SOL 005 (V2.4.1): "Network Functions Virtualisation (NFV) Release 2; Protocols
and Data Models; RESTful protocols specification for the Os-Ma-nfvo Reference Point".
[11] ETSI GS NFV-SOL 003 (V2.3.1): "Network Functions Virtualisation (NFV) Release 2; Protocols
and Data Models; RESTful protocols specification for the Or-Vnfm Reference Point".
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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] CRN website: "The 10 Biggest Cloud Outages Of 2013".
NOTE: Available at http://www.crn.com/slide-shows/cloud/240165024/the-10-biggest-cloud-outages-of-
2013.htm.
[i.2] ETSI GR NFV-REL 007 (V1.1.1): "Network Functions Virtualisation (NFV); Reliability; Report
on the resilience of NFV-MANO critical capabilities".
[i.3] ETSI GR NFV-IFA 021 (V0.11.0): "Network Functions Virtualisation (NFV) Release 3;
Management and Orchestration; Report on management of NFV-MANO and automated
deployment of EM and other OSS functions".
[i.4] ETSI GS NFV-TST 001 (V1.1.1): "Network Functions Virtualisation (NFV); Pre-deployment
Testing; Report on Validation of NFV Environments and Services".
[i.5] ETSI GS NFV 001 (V1.1.1): "Network Functions Virtualisation (NFV); Use Cases".
[i.6] Iulian Meamtiu and Tudor Dumistras: "Cloud Software Upgrades: Challenges and Opportunities",
IEEE conferenceInternational Workshop on the Maintenance and Evolution of Service-Oriented
and Cloud-Based Systems (MESOCA), 2011.
NOTE: Available at https://www.umiacs.umd.edu/~tdumitra/papers/MESOCA-2011.pdf.
[i.7] ETSI GS NFV-IFA 018: "Network Functions Virtualisation (NFV); Acceleration Technologies;
Network Acceleration Interface Specification".
[i.8] ETSI GS NFV-REL 003 (V1.1.2): "Network Functions Virtualisation (NFV); Reliability; Report
on Models and Features for End-to-End Reliability".
[i.9] ETSI GR NFV-TST 006 (V0.0.8): "Network Functions Virtualisation (NFV); Testing; Report on
NFV CICD and Devops".
3 Definitions and abbreviations
3.1 Definitions
For the purposes of the present document, the following terms and definitions apply:
software rollback: software modification process that reverts the system from the newly deployed software version to
the previously deployed software version
software update: software modification process for bug fixes or enhancements without adding, modifying or removing
functionality, interfaces or protocols
software upgrade: software modification process aimed at adding, modifying or removing functionality, interfaces or
protocols
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3.2 Abbreviations
For the purposes of the present document, the following abbreviations apply:
BSS Business Support System
CompHost Compute Host
DF Deployment Flavor
DUT Devices Under Test
EM Element Manager
EMS Element Management System
EPC Evolved Packet Core
FUT Functions Under Test
IE Information Element
IMS IP Multimedia System
KPI Key Performance Indicator
LCM Life Cycle Management
MANO Management and Orchestration
NAT Network Address Translation
NFV TST ETSI NFV Test Working Group
NFV Network Function Virtualisation
NFVI NFV Infrastructure
NFVO NFV orchestrator
NS Network Service
NSD Network Service Descriptor
O&M Operation and Maintenance
OS Operating System
OSS Operations Support System
PNF Physical Network Function
SDN Software defined Network
SUT System Under Test
VIM Virtualised Infrastructure Manager
VNF Virtual Network Function
VNFC VNF Component
VNFD VNF Descriptor
VNFFG VNF Forwarding Graph
VNFM VNF Manager
VPN Virtual Private Network
VR Virtualised Resource
4 Overview
The intent of the present document is to specify requirements for the purpose of Software Modifications, such that
service availability and continuity in an NFV environment are maintained. All types of software related to NFV (e.g.
VNFs, MANO and NFVI) are considered for the software modification process; in addition, required controlling and
supporting functionality is addressed. Where applicable, external specifications may be referenced to avoid duplication
of work.
It should be noted that supporting work on the test processes for Software Modification is addressed by the ETSI NFV
Test Working Group (NFV TST). As appropriate, references to the TST work and/or brief descriptions of the developed
test processes are provided. An overview of the overall document framework is as follows.
Software related to NFV may be of different types. Clause 5.1 refers to the three working domains identified for NFV in
previous work [1] and associates specific software types to these domains. The purpose for delineating these individual
software types is to align specific processes or methods that may apply to the modification of each type of software as
well as the corresponding requirements to support such processes. The software types are as follows:
• Clause 5.1.2 - VNFs that support the full range of Network Services and Applications: note that components
comprising a VNF are referred to as VNF Components (VNFC). Thus modifications may be done for
individual VNFCs or VNFs. VNF Descriptors and Attributes are included as appropriate.
• Clause 5.1.3 - MANO Software: Software components that provide MANO functionality.
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• Clause 5.1.4 - NFVI Software: Software components that support NFV Infrastructure.
Software Updates and Upgrades have been defined for VNFs as follows [3]:
• A VNF update does not introduce new functionality and/or new interfaces.
• A VNF upgrade might introduce new functionality and/or new interfaces.
Detailed definitions for these terms indicating precise intent for these actions are provided in clause 3.1. Note that they
apply to VNFs, NFVI, and MANO software components.
Software modification implications are presented in clause 5.2.
The methods by which modifications are instituted are as follows:
• "NetOps" or Network Operations - This method involves significant manual involvement throughout the
modification process followed by substantial levels of testing by the Network Operator. Typically, this method
could be instituted when major changes in software are involved with careful management of resource
utilization. Additionally, it is expected that major changes will not be very frequent; this may allow for a
carefully planned modification and testing process.
• "DevOps" or Development Operations - This method is fully automated end-to-end. The magnitude of changes
is expected to be small for each new version and allows for automated testing throughout the process delivery
cycle. It is also expected that such changes could be fairly frequent (e.g. multiple changes on a daily basis).
The DevOps method is out of scope for the present document.
Clause 6 is structured as follows
• Clause 6.1: This clause provides an overview and introduces the phases of the software modification process.
• Clause 6.2: This clause describes the overall software modification process.
• Clause 6.3: Software Modification Requirements. This clause provides detailed normative requirements for
modification of VNFs, MANO components, and NFVI components.
• Clause 6.4: Rollback of Software Modifications. This clause provides requirements on how to deal with
problem situations associated with the software modification process.
• Clause 6.5: Test Process Implications. The test processes developed in the ETSI NFV TST Working Group are
referenced and briefly described as applicable.
Additional information that is relevant for the software modification process is provided in informative annexes A, B
and C.
5 NFV Software
5.1 Types of NFV Software
5.1.1 Introduction
The types of NFV Software that are in scope for the software modification process are described in ETSI
GS NFV 002 [1], clause 5.2 as follows:
"Network Functions Virtualisation" envisages the implementation of NFs as software-only entities that run over the
NFV Infrastructure (NFVI). Figure 1 illustrates the high-level NFV framework. As such, three main working
domains are identified in NFV:
• Virtualised Network Function, as the software implementation of a network function which is capable of
running over the NFVI.
• NFV Infrastructure (NFVI), including the diversity of physical resources and how these can be virtualised.
NFVI supports the execution of the VNFs.
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• NFV Management and Orchestration, which covers the orchestration and lifecycle management of physical
and/or software resources that support the infrastructure virtualisation, and the lifecycle management of VNFs.
NFV Management and Orchestration focuses on all virtualisation-specific management tasks necessary in the
NFV framework.
Figure 1 from clause 5.2 of ETSI GS NFV 002 [1] depicts the three working domains; this is shown below. The VNF
domain is supported by the NFVI domain and both of these domains are managed by the MANO domain.

Figure 1: High Level NFV Framework as shown in clause 5.2 of ETSI GS NFV 002 [1]
The software in scope for the present document relates to these three domains.
5.1.2 VNF Domain Software
There are two types of VNF domain software:
1) Individual VNFs: Virtualised network functions that perform a given network task. Examples of individual
VNFs include:
a) Network Address Translation (NAT)
b) Firewall
c) Load Balancer
2) Network Services: An end-to-end Network Service is defined in ETSI GS NFV 002 [1] as a Forwarding Graph
(FG) of the necessary Network Functions that support the desired service. This FG of Network Functions can
include a combination of Physical Network Functions (PNF) as well as VNFs. From the perspective of the
present document, only the portion of the FG that contains VNFs is in scope. Examples of services include the
following:
a) Mobile Voice/Data
b) Internet Access
c) Virtual Private Network (VPN)
5.1.3 MANO Domain Software
MANO domain software support the three MANO Functional Blocks in ETSI GS NFV-MAN 001[2]:
1) VNF Manager (VNFM).
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2) Virtualised Infrastructure Manager (VIM).
3) NFV Orchestrator (NFVO).
It is assumed that the software for these Functional Blocks will need to be modified in their entirety; at the moment
there is no breakdown available for splitting these blocks into smaller components.
5.1.4 NFVI Software
NFVI Software comprises the set of software that support all VNFs and Network Services. Examples of NFVI Soft
...