ETSI GS NFV-SWA 001 V1.1.1 (2014-12)

Network Functions Virtualisation (NFV); Virtual Network Functions Architecture

DGS/NFV-SWA001

General Information

• Status: Published
• Publication Date: 22-Dec-2014
• Technical Committee: NFV SWA - Software Architecture
• Current Stage: 12 - Completion
• Due Date: 19-Jan-2015
• Completion Date: 23-Dec-2014

Standards Content (Sample)

GROUP SPECIFICATION
Network Functions Virtualisation (NFV);
Virtual Network Functions Architecture
Disclaimer
This 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.

2 ETSI GS NFV-SWA 001 V1.1.1 (2014-12)

Reference
DGS/NFV-SWA001
Keywords
architecture, functional, NFV, requirements
ETSI
650 Route des Lucioles
F-06921 Sophia Antipolis Cedex - FRANCE

Tel.: [phone]  Fax: [phone]

Siret N° 348 623 562 00017 - NAF 742 C
Association à but non lucratif enregistrée à la
Sous-Préfecture de Grasse (06) N° 7803/88

Important notice
The present document can be downloaded from:
http://www.etsi.org
The present document may be made available in electronic versions and/or in print. The content of any electronic and/or
print versions of the present document shall not be modified without the prior written authorization of ETSI. In case of any
existing or perceived difference in contents between such versions and/or in print, the only prevailing document is the
print of the Portable Document Format (PDF) version kept on a specific network drive within ETSI Secretariat.
Users of the present document should be aware that the document may be subject to revision or change of status.
Information on the current status of this and other ETSI documents is available at
http://portal.etsi.org/tb/status/status.asp
If you find errors in the present document, please send your comment to one of the following services:
http://portal.etsi.org/chaircor/ETSI_support.asp
Copyright Notification
No part may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying
and microfilm except as authorized by written permission of ETSI.
The content of the PDF version shall not be modified without the written authorization of ETSI.
The copyright and the foregoing restriction extend to reproduction in all media.

© European Telecommunications Standards Institute 2014.
All rights reserved.
TM TM TM
DECT , PLUGTESTS , UMTS and the ETSI logo are Trade Marks of ETSI registered for the benefit of its Members.
TM
3GPP and LTE™ are Trade Marks of ETSI registered for the benefit of its Members and
of the 3GPP Organizational Partners.
GSM® and the GSM logo are Trade Marks registered and owned by the GSM Association.
ETSI
3 ETSI GS NFV-SWA 001 V1.1.1 (2014-12)
Contents
Intellectual Property Rights . 6
Foreword . 6
Modal verbs terminology . 6
1 Scope . 7
2 References . 7
2.1 Normative references . 7
2.2 Informative references . 7
3 Definitions and abbreviations . 9
3.1 Definitions . 9
3.2 Abbreviations . 10
4 Overview of VNF in the NFV Architecture . 12
4.1 Introduction . 12
4.2 VNF Architecture . 13
4.3 Interfaces . 15
4.3.1 VNF Interfaces and NFV Architectural Framework Reference Points . 15
4.3.2 SWA-1 Interfaces . 17
4.3.3 SWA-2 Interfaces . 18
4.3.4 SWA-3 Interfaces . 18
4.3.5 SWA-4 Interfaces . 19
4.3.6 SWA-5 Interfaces . 19
5 VNF Design Patterns and Properties . 20
5.1 VNF Design Patterns . 20
5.1.1 VNF Internal Structure . 20
5.1.2 VNF Instantiation . 21
5.1.3 VNFC States . 21
5.1.4 VNF Load Balancing Models . 22
5.1.5 VNF Scaling Models . 24
5.1.6 VNF Component Re-Use . 25
5.2 VNF Update and Upgrade . 27
5.2.1 VNF Update and Upgrade Overview . 27
5.2.2 VNF Update & Upgrade Requirements for VNF Provider . 27
5.3 VNF's Properties . 27
5.3.1 Hardware Independence . 27
5.3.2 Virtualisation and Container Awareness. 28
5.3.3 Elasticity . 28
5.3.4 Void . 29
5.3.5 VNF Policy Management . 29
5.3.6 Migration operations . 29
5.3.7 VNF State . 30
5.3.8 VNF Internal Structure . 30
5.3.9 Reliability . 30
5.3.10 Location Awareness . 30
5.3.11 Application Management . 30
5.3.12 Diversity and Evolution of VNF Properties . 31
5.4 Attributes describing VNF's Requirements . 31
5.4.1 VNF Topological Characteristics . 31
5.4.1.1 Deployment Behaviour . 32
5.4.1.1.1 Virtualisation containers . 32
5.4.1.1.2 NFVI Resources . 32
5.4.1.1.3 Components and Relationship . 32
5.4.1.1.4 Location . 32
5.4.1.1.5 Other constraints . 32
5.4.1.2 Operational Behaviour . 32
ETSI
4 ETSI GS NFV-SWA 001 V1.1.1 (2014-12)
5.4.1.2.1 Management Operations . 32
6 VNF States and Transitions . 33
6.1 States and Transitions as Architectural Patterns . 33
6.2 VNF Instantiation Overview . 34
6.3 The VNF Descriptor's Role in VNF Instantiation . 35
6.4 VNF Instantiation . 36
6.5 VNFC Instantiation . 37
6.6 VNFC Instance Termination . 37
6.7 VNF Instance Termination . 38
6.8 VNF Instance Scaling . 38
6.8.1 General Aspects . 38
6.8.2 Scaling Triggers . 38
6.8.3 VNF Scale-out . 38
6.8.4 VNF Scale-in . 39
6.8.5 VNF Scale-up . 39
6.8.6 VNF Scale-down . 39
6.9 Start and Stop VNF . 40
6.9.1 Start VNF . 40
6.9.2 Stop VNF . 40
6.10 VNF Instance Configuration . 40
7 VNF Fault Management Overview . 41
7.1 Introduction . 41
7.2 Virtualised resource faults . 41
7.3 VNF faults . 42
8 Functional Requirements on Management and Orchestration . 42
8.1 High Level Requirements to Management and Orchestration . 42
8.1.1 General Management and Orchestration Requirements related to VNF . 42
8.1.2 Management and Orchestration Requirements Related to VNF Lifecycle . 43
8.1.3 Management and Orchestration Requirements Related to Scaling . 43
8.1.4 Management and Orchestration Requirements Related to VNF Maintenance Tasks . 44
8.2 Requirements for VNFD and VNF-FGD Template . 45
8.2.1 General Requirements Related to VNF . 45
8.2.2 General Requirements Related to VNF Forwarding Graphs . 46
8.2.3 Requirements Related to VNF Creation and Termination . 46
8.2.4 Requirements Related to Scaling . 47
9 Functional Requirements on Infrastructure . 47
9.1 Generic Domain Requirements . 47
9.2 Hypervisor Requirements . 48
9.3 Compute Resource Requirements . 49
9.4 Network Resources Requirements. 49
10 VNF Architecture Design Examples . 50
10.1 Faster VNFC . 50
10.2 VNFC to VNFC Communication . 51
10.3 VNFC Memory to VNFC Memory . 53
10.4 Faster Network Access . 53
10.5 Fast Storage Access . 54
10.6 Driver version, Software Updates . 55
10.7 Distributed VNF . 56
10.8 Generic VNFs . 56
10.8.1 Definition and Usage . 56
Annex A (informative): Relationship to SDN. 57
A.1 Introduction to SDN . 57
A.1.1 ONF and SDN . 57
A.1.2 OpenDaylight and SDN . 57
A.1.3 IETF and SDN . 57
A.1.4 ITU-T and SDN . 58
A.1.4.1 Introduction. 58
ETSI
5 ETSI GS NFV-SWA 001 V1.1.1 (2014-12)
A.1.4.2 Protocol: SDN control . 58
A.1.5 SDN Architecture Overview . 59
A.2 SDN in NFV Architecture . 60
A.2.1 Overview . 60
A.3 ETSI NFV Use Case and SDN . . 62
A.3.1 L2 Transparent Network Service Chaining with Traffic Steering . 62
A.3.1.1 Problem Description . 62
A.3.1.1.1 L2 Transparent Network Services . 62
A.3.1.1.1.1 Physical Server Deployments . 62
A.3.1.1.1.2 Virtual Server Deployments . 64
A.3.1.2 Solution Description & Relationship to SDN/OF . 65
A.3.1.2.1 SDN/OF virtual switches . 65
A.3.1.2.2 Role of SND/OF in Service Chaining Traffic Steering . 65
A.3.1.3 Requirements to Management and Orchestration . 70
A.3.1.4 Gap Analysis with ONF . 71
Annex B (informative): De/composition Study . 72
B.1 MRF IMS Use Case . 72
B.1.1 Functional Description . 73
B.1.2 Location of FBs within the NFV Architecture . 74
B.1.3 New Interfaces . 74
B.1.4 VNF Identification . 75
B.1.4.1 MRB . 76
B.1.4.2 MRF . 77
B.1.4.3 IMS MRF Deployment . 78
B.1.5 Standardization Gap . 79
B.2 DPI Engine VNFC Use Case . 79
B.2.1 Declination of the DPI Engine . 80
B.2.2 Scalability Benefits. 81
B.2.3 Security and OpEx Benefits . 82
B.3 Virtual Enterprise Gateway Use Case . 82
B.4 TDF as VNF Use Case . 88
B.4.1 Functional Block Description . 89
B.4.2 TDF Functional Blocks within the NFV architecture . 90
B.4.3 Existing interfaces (as per ETSI TS 123 203) . 90
Annex C (informative): Authors & contributors . 91
Annex D (informative): Bibliography . 92
History . 93

ETSI
6 ETSI GS NFV-SWA 001 V1.1.1 (2014-12)
Intellectual Property Rights
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 (http://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.
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", "may not", "need", "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.
ETSI
7 ETSI GS NFV-SWA 001 V1.1.1 (2014-12)
1 Scope
The present document objective is to identify the most common and relevant software architectural patterns present
when virtualising network functions and therefore to identify and specify functional requirements necessary to enable
such patterns. The information consolidated is reflecting the experience from vendors and operators going through
virtualisation of a number of network functions, with a focus on the use case list provided by the NFV Use Cases GS
document [i.7].
The present document describes the Network Function Virtualisation abstract software architecture comprising of the
following topics:
• Defining the functions, and interfaces of software architecture relative to the NFV overall architecture.
• Supporting Management and Orchestration Functional requirements.
• Supporting Infrastructure requirements.
• Describing best practices for NFV Design.
• Functional Decomposition types and use cases.
The present document does not provide any detailed specification. However, the present document makes reference to
specifications developed by other bodies, gap, and to potential specifications.
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
http://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.
Not applicable.
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-INF 001: "Network Functions Virtualisation (NFV); Infrastructure Overview".
[i.2] ETSI GS NFV-INF 005: "Network Functions Virtualisation (NFV); Infrastructure; Network
Domain".
ETSI
8 ETSI GS NFV-SWA 001 V1.1.1 (2014-12)
[i.3] ETSI GS NFV-MAN 001: "Network Functions Virtualisation (NFV); Management and
Orchestration".
[i.4] ETSI GS NFV 002 (V1.1.1): "Network Functions Virtualisation (NFV); Architectural
Framework".
[i.5] ETSI GS NFV 004 (V1.1.1): "Network Functions Virtualisation (NFV); Virtualisation
Requirements".
[i.6] ETSI GS NFV 003 (V1.1.1): "Network Functions Virtualisation (NFV); Terminology for Main
Concepts in NFV".
[i.7] ETSI GS NFV 001 (V1.1.1): "Network Functions Virtualisation (NFV); Use Cases".
[i.8] ETSI GS NFV-PER 001: "Network Functions Virtualisation (NFV); NFV Performance &
Portability Best Practises".
[i.9] ETSI GS NFV-REL 001: "Network Functions Virtualisation (NFV); Resiliency Requirements".
[i.10] Open Data Center Alliance, ODCA Service Orchestration Master Usage Model, ODCA.
NOTE: Available at
http://www.opendatacenteralliance.org/docs/ODCA_Service_Orch_MasterUM_v1.0_Nov2012.pdf.
[i.11] ETSI TS 123 228: "Digital cellular telecommunications system (Phase 2+); Universal Mobile
Telecommunications System (UMTS); LTE; IP Multimedia Subsystem (IMS); Stage 2
(3GPP TS 23.228)".
[i.12] ETSI TS 123 218: "Digital cellular telecommunications system (Phase 2+); Universal Mobile
Telecommunications System (UMTS); LTE; IP Multimedia (IM) session handling; IM call model;
Stage 2 (3GPP TS 23.218)".
[i.13] ISO/IEC 42010:2011: "Systems and Software Engineering - Architecture Description".
[i.14] ATIS-I-0000044 (October 2013): "Operational opportunities and challenges of SDN/NFV
programmable infrastructure", section 4.2.1.1 "Service Provider Devops".
[i.15] ETSI TS 123 203: "Digital cellular telecommunications system (Phase 2+); Universal Mobile
Telecommunications System (UMTS); LTE; Policy and charging control architecture
(3GPP TS 23.203)".
[i.16] ETSI TS 132 251: "Digital cellular telecommunications system (Phase 2+); Universal Mobile
Telecommunications System (UMTS); LTE; Telecommunication management; Charging
management; Packet Switched (PS) domain charging (3GPP TS 32.251)".
[i.17] ETSI TS 132 240: "Digital cellular telecommunications system (Phase 2+); Universal Mobile
Telecommunications System (UMTS); LTE; Telecommunication management; Charging
management; Charging architecture and principles (3GPP TS 32.240)".
[i.18] Open Network Foundation, ONF.
NOTE: Available at https://www.opennetworking.org/sdn-resources/sdn-definition.
[i.19] PCI Single Route I/O Virtualization (SR-IOV). [Online].
NOTE: Available at http://www.pcisig.com/specifications/iov/.
[i.20] Recommendation ITU-T H.248.1 (03/2013): "Gateway control protocol: Version 3".
[i.21] Technical Report Draft TR H.Sup.OpenFlow (2014): "Protocol evaluation - OpenFlow versus
H.248".
NOTE: Latest draft available at http://wftp3.itu.int/av-arch/avc-site/2013-2016/1403_Gen/TD-19.zip.
[i.22] Recommendation ITU-T M.3050.1 (03/2007): "Enhanced Telecom Operations Map (eTOM) - The
business process framework".
ETSI
9 ETSI GS NFV-SWA 001 V1.1.1 (2014-12)
[i.23] Recommendation ITU-T M.3010 (02/2000): "Principles for a telecommunications management
network".
[i.24] Recommendation ITU-T M.3400 (02/2000): "TMN management functions".
[i.25] Recommendation ITU-T X.700 (09/1992): "Management framework for Open Systems
Interconnection (OSI) for CCITT applications".
[i.26] ETSI GS NFV-PER 002 (V1.1.1): "Network Functions Virtualisation (NFV); Proofs of Concepts;
Framework".
[i.27] IETF RFC 3031 (January 2001): "Multiprotocol Label Switching Architecture", E. Rosen, A.
Viswanathan and R. Callon.
[i.28] IETF RFC 3069 (February 2001): "VLAN Aggregation for Efficient IP Address Allocation", D.
McPherson and B. Dykes.
[i.29] IETF RFC 3809 (June 2004): "Generic Requirements for Provider Provisioned Virtual Private
Networks (PPVPN)", A. Nagarajan.
[i.30] IETF RFC 4385 (February 2006): "Pseudowire Emulation Edge-to-Edge (PWE3) Control Word
for Use over an MPLS PSN", S. Bryant, G. Swallow, L. Martini and D. McPherson.
[i.31] IETF RFC 4464 (May 2006): "Signaling Compression (SigComp) Users' Guide", A. Surtees and
M. West.
[i.32] IETF RFC 4761 (January 2007): "Virtual Private LAN Service (VPLS) Using BGP for Auto-
Discovery and Signaling", K. Kompella and Y. Rekhter.
[i.33] Recommendation ITU-T Y.3300 (06/2014): "Framework of software-defined networking".
[i.34] ETSI TS 129 333: "Digital cellular telecommunications system (Phase 2+); Universal Mobile
Telecommunications System (UMTS); Multimedia Resource Function Controller (MRFC) -
Multimedia Resource Function Processor (MRFP) Mp interface; Stage 3 (3GPP TS 29.333)".
3 Definitions and abbreviations
3.1 Definitions
For the purposes of the present document, the following terms and definitions apply:
compute node: See ETSI GS NFV-INF 001 [i.1].
Network Function (NF): See ETSI GS NFV 003 [i.6].
Network Function Virtualisation Infrastructure (NFVI): See ETSI GS NFV 003 [i.6].
Network Functions Virtualisation Orchestrator (NFVO): See ETSI GS NFV-MAN 001 [i.3].
NF Forwarding Graph: See ETSI GS NFV 003 [i.6].
NF Set: See ETSI GS NFV 003 [i.6].
Physical Network Function (PNF): See ETSI GS NFV 003 [i.6].
network service: See ETSI GS NFV 003 [i.6].
Virtual Machine (VM): See ETSI GS NFV 001 [i.1].
virtualisation container: partition of a compute node that provides an isolated virtualised computation environment
NOTE: Examples of virtualisation container includes virtual machine and OS container.
Virtualisation Deployment Unit (VDU): See ETSI GS NFV-MAN 001 [i.3].
ETSI
10 ETSI GS NFV-SWA 001 V1.1.1 (2014-12)
Virtualised Network Function (VNF): See ETSI GS NFV 003 [i.6].
Virtualised Network Function Component (VNFC): See ETSI GS NFV 003 [i.6].
Virtualised Network Function Component (VNFC) Instance: See ETSI GS NFV 003 [i.6].
VNF Descriptor (VNFD): See ETSI GS NFV-MAN 001 [i.3].
VNF Forwarding Graph (VNF-FG): See ETSI GS NFV 003 [i.6].
VNF Instance: See ETSI GS NFV-MAN 001 [i.3].
VNF Network Connectivity Topology (VNF-NCT): graph that defines the connectivity topology among (v)NFs by
describing how its nodes are connected to one another
VNF Package: See ETSI GS NFV-MAN 001 [i.3].
VNF Provider: entity that provides VNF Package(s)
VNF Set: See ETSI GS NFV 003 [i.6].
3.2 Abbreviations
For the purposes of the present document, the following abbreviations apply:
ADC Application Detection and Control
API Application Programming Interface
AppVM Application Virtual Machines
ATM Asynchronous Transfer Mode
BFCP Binary Floor Control Protocol
BGP Border Gateway Protocol
BGP-LS Border Gateway Protocol - Link State
BRAS Broadband Remote Access Server
CDN Content Delivery Network
COTS Commercial off the Shelf
CPU Central Processing Unit
CSCF Call Session Control Function
DB DataBase
DDoS Distributed Denial of Service
DHCP Dynamic Host Configuration Protocol
DNS Domain Nane Server
DPDK Data Plane Development Kit
DPI Deep Packet Inspection
DRA Diameter Routing Agent
DSCP Differentiated Services Code Point
DSP Digital Signal Processor
DSR Direct Server Return
ELAN Ethernet Virtual Private LAN
EM Element Management
EPC Evolved Packet Core
ETH Ethernet
eTOM enhanced Telecom Operations Map
EVPN Ethernet VPN
FAB Fulfilment, Assurance, Billing
FCAPS Fault, Configuration, Accounting, Performance, Security
FORCES FOrwarding and Control Element Separation
FRR Fast ReRoute
GGSN Gateway GPRS Service Node
GTP GPRS Tunnel Protocol
GW Gateway
HDW Hardware
HTTP Hypertext Transfer Portocol
HW Hardware
ETSI
11 ETSI GS NFV-SWA 001 V1.1.1 (2014-12)
I2SR Interface 2 the Routing System
IB Infiniband
IDPS Intrusion Detection And Prevention Systems
IGMP Internet Group Management Protocol
IGP Internet Gateway Protocol
IMS IP Multimedia Subsystem
IO Input Output
IP Internet Protocol
IPS Intrusion Prevention System
ISA Industry Standard Architecture
ISO International Organisation for Standardization
IT Information Technology
LAG Link Aggregation Groups
LAN Local Area Network
LB Load Balancer
LISP Location Identifier Separation Protocol
LSP Label Switched Paths
MAC Media Access Control
MEF Metro Ethernet Forum
MME Mobility Management Entity
MPLS Multiprotocol Label Switching
MRB Media Resource Broker
MRF Media Resource Function
MRF-C Multimedia Resource Function Controller
MRF-P Multimedia Resource Function Processor
MSRP Message Session Relay Protocol
NAT Network Address Translation
NF Network Function
NFV Network Function Virtualisation
NFVI NFV Infrastructure
NFVO Network Functions Virtualisation Orchestrator
NIC Network Interface Controller
NVFI Network Functions Virtualisation Infrastructure
NVGRE Network Virtualisation using Generic Routing Encapsulation
OAM Operations, Administration and Maintenance/Management
OCS Online Charging Function
OF OpenFlow
OFCS Offline Charging Function
OFLS OpenFlow Logical Switch
ONF Open Networking Foundation
OS Operating System
OSS Operations Support System
PCC Policy and Charging Control
PCEF Policy and Charging Enforcement Function
PCRF Policy and Charging Rules Function
PGW Packet Data Network Gateway
PMIP Proxy Mobile IP
PNF Physical Network Function
RAM Random Access Memory
RDBMS Relational Data Base Management System
REQ Requirement
RFC Request For Comment
RLOC Routing Locator
RTCP Real-time Transport Control Protocol
RTP Real-time Transport Protocol
SCSI Small Computer System Interface
SDK Software Development Kit
SDN Software Defined Networks
SIP Session Initiation Protocol
SLA Service Level Agreement
SNMP Signalling Network Management Protocol
SSL Secure Socket Layer
ETSI
12 ETSI GS NFV-SWA 001 V1.1.1 (2014-12)
SWA Software Architecture
TCP Transfer Control Protocol
TDF Traffic Detection Function
TDF-C Traffic Detection Function - Control
TDF-LB Traffic Detection Function - Load Balancer
TDF-P Traffic Detection Function - Processing
TE Traffic Engineering
TMN Telecommunications Management Network
UDP Unreliable Datagram Protocol
VDC Virtual Data Centre
VIM Virtualised Infrastructure Manager
VLAN Virtual Local Area Network
VM Virtual Machine
VNF Virtualised Network Function
VNFC Virtualised Network Function Component
VNFD Virtualised Network Function Descriptor
VNFFG VNF Forwarding Graph
VNFM Virtualised Network Function Manager
VNF-NCT VNF Network Connectivity Topology
vNIC Virtualised NIC
VoLTE Voice over LTE
VPLS Virtual Private LAN Service
VxLAN Virtual eXtensible LAN
WAF Web Application Firewall
WAN Wide Access Network
4 Overview of VNF in the NFV Architecture
4.1 Introduction
A Virtualised Network Function (VNF) is a functional element of the NFV architecture framework [i.4] as represented
on figure 1. Reference points in-scope of the present document are those between a VNF and a VNF Manager
(Ve-Vnfm) and between a VNF and NFVI (Vn-Nf), see red dashed line circle in figure 1. The present document
addresses functional requirements for virtualising network functions in the form of software components deployed
within an NFVI, in support of the deployment of network services.
Software architectures describe the functionality of software systems from the viewpoints of various stakeholders [i.13].
ETSI NFV-PER 002 [i.26] identified Proof of Concept Framework stakeholders from the membership categories
(e.g. Service Provider, Network Operator, and Manufacturer) defined in the ETSI Directives. A Manufacturer of VNFs
may have particular concerns with the software development aspects in creation of VNFs. A Network Operator may
have particular concerns with the efficient deployment and operation of VNFs within his NFVI. A Service Provider
may have particular concerns with the fulfilment, assurance and billing of services based on VNFs delivered to end
users. ETSI GS NFV 004 [i.5] also identifies requirements impacting functions based on the roles, as defined in [i.5]
Requirement [Sec. 5] of the actors initiating operations. Such roles impacting the VNF may extend beyond those
identified by the ETSI Directives' membership categories, as defined in [i.7]. Commercial entities may need to act in
multiple roles in order to meet certain NFV objectives; for example the objectives of NFV for automation, as defined in
[i.5], Requirement [OaM.1] and rapid service innovation and deployment, as defined in [i.4], clause 4.2 may lead some
entities to consider "devops" [i.14] to automate the process of development and deployment of VNFs and the end-end
network services constructed from them.
ETSI
13 ETSI GS NFV-SWA 001 V1.1.1 (2014-12)

Figure 1: NFV Software Architecture Scope within the NFV Reference Architecture Framework
As defined in [i.6] a network service is a composition of network functions, in the form of a network functions sets
and/or network forwarding graphs. The present document also addresses the requirements for deploying network
services involving at least one virtual network function.
The present document supports distributed VNF deployment models in support of end-to-end network services as
defined in [i.5], Requirement "Mod7", delivered across multiple NFVI Nodes deployed in disparate NFVI-PoPs as
defined in [i.5], Requirement "Port. 1". It shall be possible to deploy end-to-end network services across independently
operated NFVI nodes as defined in Use Case #1 (NFVIaaS) in [i.7] and Requirement "Mod 7" in [i.5], a mix of NFVI
Nodes and non-virtualised PNFs as defined in [i.5] Requirements "Mod 2", "Mig.1", and "Gen.4" and coexist with other
network services deployed in parallel in the same NFVI as defined in [i.5] Requirements "Mod. 10" and "Sec. 1".
4.2 VNF Architecture
Figure 2 shows the internal architecture of a VNF. It provides more details on the entities and interfaces relevant for the
discussion in the present document while deliberately leaving out those aspects that fall into the infrastructure and
management and orchestration domains. See [i.3] and [i.1] for details on those.
ETSI
14 ETSI GS NFV-SWA 001 V1.1.1 (2014-12)

Figure 2: Functional View
A Virtualised Network Function (VNF) is a Network Function capable of running on an NFV Infrastructure (NFVI) and
being orchestra
...