What is Network Function Virtualisation (NFV)?

A presentation about what is the concept and the idea behind Network Function Virtualisation (NFV). Includes introduction to NFV and VNF (Virtualised Network Function) architecture, components and interfaces.

1. WHAT IS NETWORK FUNCTION
VIRTUALISATION (NFV)?
V1.1 22.3.2016 Karri Huhtanen

2. Network Function Virtualisation (NFV)
In computer science, network function virtualisation
(NFV) is a network architecture concept which uses
the technologies of IT virtualisation. It is used to
virtualise entire classes of network node functions into
building blocks that may connect, or chain together,
to create communication services.

-- https://en.wikipedia.org/wiki/Network_function_virtualization

3. Virtualised Network Function (VNF)
NFV relies upon, but differs from, traditional server-virtualisation
techniques, such as those used in enterprise IT. A virtualised
network function, or VNF, may consist of one or more virtual
machines running different software and processes. They are
run on top of standard high-volume servers, switches and
storage, or even cloud computing infrastructure, instead of
having custom hardware appliances for each network function.

-- https://en.wikipedia.org/wiki/Network_function_virtualization

4. Broadband
Customers
Mobile
Network
Customers
Enterprise
Customer
Operator Core
Network
Content
Provider
Services
Operator
Services
Traditional Model
Internet
router
router
router
router
firewall
firewall
firewall
server
server
server
server
server
server
Broadband
Customers
access
gateway
router router
router
routerrouter
firewall firewall
DHCP
DNS

5. Broadband
Customers
Mobile
Network
Customers
Enterprise
Customer
Operator Core
Network
Content
Provider
Services
Operator
Services
Centralised Services
Internet
router
router
router
router
firewall
firewall
firewall
server
server
server
server
server
server
Broadband
Customers
access
gateway
router router
router
routerrouter
firewall firewall
DHCP
DNS

6. Broadband
Customers
Mobile
Network
Customers
Enterprise
Customer
Operator Core
Network
Content
Provider
Services
Operator
Services
Geographically distributed Point-of-Presences (PoPs)
Internet
router
router
router
router
firewall
firewall
firewall
server
server
server
server
server
server
Broadband
Customers
access
gateway
router router
router
routerrouter
firewall firewall
DHCP
DNS

7. Broadband
Customers
Mobile
Network
Customers
Enterprise
Customer
Operator Core
Network
Content
Provider
Services
Operator
Services
Geographically distributed dedicated hardware devices
Internet
router
router
router
router
firewall
firewall
firewall
server
server
server
server
server
server
Broadband
Customers
access
gateway
router router
router
routerrouter
firewall firewall
DHCP
DNS

8. Broadband
Customers
Mobile
Network
Customers
Enterprise
Customer
Operator Core
Network
Content
Provider
Services
Operator
Services
Static model
Internet
router
router
router
router
firewall
firewall
firewall
server
server
server
server
server
server
Broadband
Customers
access
gateway
router router
router
routerrouter
firewall firewall
DHCP
DNS
●Each device and server has its own fixed function
and capacity.
●Adding more functions or capacity requires more
devices, which is very slow.

9. Broadband
Customers
Mobile
Network
Customers
Enterprise
Customer
Operator Core
Network
Content
Provider
Services
Operator
Services
If something breaks
or overloads...
Internet
router
router
router
router
firewall
firewall
firewall
server
server
server
server
server
server
Broadband
Customers
access
gateway
router router
router
routerrouter
firewall firewall
DHCP
DNS
●Adding replacements or capacity is hard and slow.
●Devices and servers can only fill their fixed function
or role.
●Changes can only be reactive and done manually.
DDOS attack
Electricity
brown- / blackout
DHCP server
overload
SMS/MMS
Server
overload
New Game of Thrones
Season Free-For-All
Firewall
software
upgrade
failed

10. Traditional ways to cope with problems
●Allocating spare capacity, i.e. more capacity than is
needed
●Adding redundancy, spare hardware units, i.e. more
hardware than is needed
●Segmenting service areas and cells smaller => potential
problems affect less customers
●Creating manual controls, e.g. firewall filters when
DDoS is active
●Change control, proactive planning

11. The brave new world of
Network Function Virtualisation
NFV

12. Broadband
Customers
Mobile
Network
Customers
Enterprise
Customer
Operator Core
Network
Content
Provider
Services
Operator
Services
Instead of this …
Internet
router
router
router
router
firewall
firewall
firewall
server
server
server
server
server
server
Broadband
Customers
access
gateway
router router
router
routerrouter
firewall firewall
DHCP
DNS

13. Broadband
Customers
Mobile
Network
Customers
Enterprise
Customer
Operator Core
Network
Content
Provider
Services
Operator
Services
NFV offers something like this…
Internet
Broadband
Customers
firewallfirewall
router router
spare
firewallfirewall
router router
spare
spare
capacity
ac. gw ac. gw
router router dhcp
dns
cachecache
spare
capacity
sms mms
router router dhcp
dns
firewallfirewall
firewallfirewall
router router
spare
firewallfirewall
router router
spare
serverservercache

14. Broadband
Customers
Mobile
Network
Customers
Enterprise
Customer
Operator Core
Network
Content
Provider
Services
Operator
Services
Virtualised Network
Functions / devices
Internet
Broadband
Customers
●Virtualised network functions run on virtual
hosts on top of the virtualisation
infrastructure in data centers or PoPs
●Virtual infrastructure can extend across PoPs
firewallfirewall
router router
spare
firewallfirewall
router router
spare
spare
capacity
ac. gw ac. gw
router router dhcp
dns
cachecache
spare
capacity
sms mms
router router dhcp
dns
firewallfirewall
router
firewallfirewall
router router
spare
serverservercache
firewallfirewall
router router
spare

15. Broadband
Customers
Mobile
Network
Customers
Enterprise
Customer
Operator Core
Network
Content
Provider
Services
Operator
Services
Functions/services/capacity
shared across regions or customer groups
Internet
Broadband
Customers
firewallfirewall
router router
spare
firewallfirewall
router router
spare
spare
capacity
ac. gw ac. gw
router router dhcp
dns
cachecache
spare
capacity
sms mms
router router dhcp
dns
firewallfirewall
firewallfirewall
router router
spare
firewallfirewall
router router
spare
serverservercache

16. Broadband
Customers
Mobile
Network
Customers
Enterprise
Customer
Operator Core
Network
Content
Provider
Services
Operator
Services
Extra capacity
available freely
Internet
Broadband
Customers
●Any spare capacity can be allocated for any VNF
●Roles and functions are dynamic, not fixed
●Actual hardware capacity can be utilised more
efficiently across regions and customers

firewallfirewall
router router
spare
firewallfirewall
router router
spare
spare
capacity
ac. gw ac. gw
router router dhcp
dns
cachecache
spare
capacity
sms mms
router router dhcp
dns
firewallfirewall
firewallfirewall
router router
spare
firewallfirewall
router router
spare
serverservercache

17. Broadband
Customers
Mobile
Network
Customers
Enterprise
Customer
Operator Core
Network
Content
Provider
Services
Operator
Services
Capacity is general-
purpose capacity
Internet
Broadband
Customers
firewallfirewall
router router cache
cache firewallfirewall
router router firewall
firewall
ac. gw ac. gw
router router cache
dns
cachecachecachecache
router
ac. gw
sms mms
router router dhcp
dns
firewallfirewallmmsspare
router
sms firewallfirewall
router router spare
firewall
firewallfirewall
router router server
cache
serverservercache
●Capacity can be allocated automatically
●Roles and functions can be changed according
current needs or detected anomalies
●Reconfiguration/scaling can be done automatically
Broadband Customer and Mobile Network PoPs prepare for
prime time in streaming by repurposing capacity to streaming
caches and regional routing and access capacity.
Enterprise customer
fights DDoS with
additional firewall
capacity
Operator prepares for peak
in SMS/MMS messages
Content Service
Provider adds
more capacity
and caching for
prime time
Prime time traffic
requires more firewall
capacity

18. But wait, there’s even more…

19. Broadband
Customers
Mobile
Network
Customers
Enterprise
Customer
Operator Core
Network
Content
Provider
Services
Operator
Services
This is called Network Function Virtualisation
Infrastructure (NFVI)…
Internet
Broadband
Customers
firewallfirewall
router router
spare
firewallfirewall
router router
spare
spare
capacity
ac. gw ac. gw
router router dhcp
dns
cachecache
spare
capacity
sms mms
router router dhcp
dns
firewallfirewall
firewallfirewall
router router
spare
firewallfirewall
router router
spare
serverservercache

20. Broadband
Customers
Mobile
Network
Customers
Enterprise
Customer
Operator Core
Network
Content
Provider
Services
Operator
Services
Each of the small boxes can be
a Virtualised Network Function (VNF) …
Internet
Broadband
Customers
firewallfirewall
router router
spare
firewallfirewall
router router
spare
spare
capacity
ac. gw ac. gw
router router dhcp
dns
cachecache
spare
capacity
sms mms
router router dhcp
dns
firewallfirewall
firewallfirewall
router router
spare
firewallfirewall
router router
spare
serverservercache

21. Each of the VNFs can consist of multiple
components (VNFC) …
FIREWALL VNF
Load
balancer
Load
balancer
Packet
Filter
Packet
Filter
Packet
Filter
Packet
Filter
Stateful
Firewall
Stateful
Firewall
Stateful
Firewall
Stateful
Firewall
Policy
and Rule
Database
Policy
and Rule
Database

VNFC

VNFC

VNFC

VNFC
autoscaling
●Each Virtualised Network
Function Component (VNFC)
may consist of several virtual
hosts, which automatically
scale up and down when
needed.

●VNFs and VNFCs can both
provide e.g. REST or netconf
interfaces for management,
monitoring and integration
purposes.

22. Idea is that VNFCs and VNFs can be re-used…
ENTERPRISE SITE VNF
FIREWALL VNF AUTHENTICATION
AUTHORISATION
ACCOUNTING
VNF
ROUTER VNF
VPN VNF STORAGE VNFCLOUD BACKUP
VNF
●… as building blocks of
new VNFs and services.
●They are supposed to
have web services like
REST APIs => web
developers are supposed
to be able to build
operator customer self-
service portals
●Standardised interfaces
should mean better
vendor interoperability
=> avoiding vendor lock-
ins

23. ETSI NFV Architecture and
Interfaces

24. NFVI
OSS/BSS
EM1 EM2
VNF3VNF1 VNF2
EM3
Virtual
Computing
Virtual
Storage
Virtual
Network
Computing
Hardware
Storage
Hardware
Network
Hardware
VirtualisationLayer
Vn-Nf
VI-Ha
NFV Management and Orchestration
NFV
Orchestrator
VNF Manager
(s)
Virtualised
Infrastructure
Manager(s)
VNF Manager
(s)VNF Manager
(s)
Os-Ma
Ve-Vnfm
Nf-Vi
Or-Vnfm
Vi-Vnfm
Service, VNF and
Infrastructure
Description
Or-Vi
According to ETSI GS NFV-SWA 001 V1.1.1 (2014-12):
Network Functions Virtualisation (NFV); Virtual Network Functions Architecture

25. NFVI
OSS/BSS
EM1 EM2
VNF3VNF1 VNF2
EM3
Virtual
Computing
Virtual
Storage
Virtual
Network
Computing
Hardware
Storage
Hardware
Network
Hardware
VirtualisationLayer
Vn-Nf
VI-Ha
NFV Management and Orchestration
NFV
Orchestrator
VNF Manager
(s)
Virtualised
Infrastructure
Manager(s)
VNF Manager
(s)VNF Manager
(s)
Os-Ma
Ve-Vnfm
Nf-Vi
Or-Vnfm
Vi-Vnfm
Service, VNF and
Infrastructure
Description
Or-Vi
Operations Support System (OSS),
Billing Support System (BSS)
Element
Management
(EM)
MANO
VNFM
VIM

26. NFVI
OSS/BSS
EM1 EM2
VNF3VNF1 VNF2
EM3
Virtual
Computing
Virtual
Storage
Virtual
Network
Computing
Hardware
Storage
Hardware
Network
Hardware
VirtualisationLayer
Vn-Nf
VI-Ha
NFV Management and Orchestration
NFV
Orchestrator
VNF Manager
(s)
Virtualised
Infrastructure
Manager(s)
VNF Manager
(s)VNF Manager
(s)
Os-Ma
Ve-Vnfm
Nf-Vi
Or-Vnfm
Vi-Vnfm
Service, VNF and
Infrastructure
Description
Or-Vi
Main NFV reference points

27. NFVI
OSS/BSS
EM1 EM2
VNF3VNF1 VNF2
EM3
Virtual
Computing
Virtual
Storage
Virtual
Network
Computing
Hardware
Storage
Hardware
Network
Hardware
VirtualisationLayer
Vn-Nf
VI-Ha
NFV Management and Orchestration
NFV
Orchestrator
VNF Manager
(s)
Virtualised
Infrastructure
Manager(s)
VNF Manager
(s)VNF Manager
(s)
Os-Ma
Ve-Vnfm
Nf-Vi
Or-Vnfm
Vi-Vnfm
Service, VNF and
Infrastructure
Description
Or-Vi
Execution reference points

28. NFVI
OSS/BSS
EM1 EM2
VNF3VNF1 VNF2
EM3
Virtual
Computing
Virtual
Storage
Virtual
Network
Computing
Hardware
Storage
Hardware
Network
Hardware
VirtualisationLayer
Vn-Nf
VI-Ha
NFV Management and Orchestration
NFV
Orchestrator
VNF Manager
(s)
Virtualised
Infrastructure
Manager(s)
VNF Manager
(s)VNF Manager
(s)
Os-Ma
Ve-Vnfm
Nf-Vi
Or-Vnfm
Vi-Vnfm
Service, VNF and
Infrastructure
Description
Or-Vi
Other reference points

29. NFVI
OSS/BSS
EM1 EM2
VNF3VNF1 VNF2
EM3
Virtual
Computing
Virtual
Storage
Virtual
Network
Computing
Hardware
Storage
Hardware
Network
Hardware
VirtualisationLayer
Vn-Nf
VI-Ha
NFV Management and Orchestration
NFV
Orchestrator
VNF Manager
(s)
Virtualised
Infrastructure
Manager(s)
VNF Manager
(s)VNF Manager
(s)
Os-Ma
Ve-Vnfm
Nf-Vi
Or-Vnfm
Vi-Vnfm
Service, VNF and
Infrastructure
Description
Or-Vi
OpenStack HEAT
Overture
OpenMano
Nokia
Ericsson
HP ...
Overture,
vendor own
VNFMs
OpenStack
VMWare
WindRiver
Canonical
Red Hat
Ubuntu
Suse
HP
...
Nokia
Ericsson
Juniper
Cisco
HP
Radiator
...
Implementations

30. VNF architecture
Virtualised Network Function (VNF)
Virtualised Network Function Infrastructure
(VNFI)
Element Management (EM)
Virtualised Network
Function Manager
(VNFM)
Virtualised
Network Function
Component
(VNFC)
Virtualised
Network Function
Component
(VNFC)
Vn-Nf
SWA-5
Vn-Nf
SWA-5
SWA-4
SWA-3
Ve-Vnfm-vnf
SWA-1
SWA-2
According to ETSI GS NFV-SWA 001 V1.1.1 (2014-12):
Network Functions Virtualisation (NFV); Virtual Network
Functions Architecture

31. VNF definition by ETSI
“A Virtualised Network Function (VNF) is a Network
Function capable of running on an NFV Infrastructure
(NFVI) and being orchestrated by a NFV Orchestrator
(NFVO) and VNF Manager. It has well-defined interfaces to
other NFs via SWA1, the VNF Manager, its EM, and the
NFVI and a well-defined functional behaviour.”
ETSI GS NFV-SWA 001 V1.1.1 (2014-12):
Network Functions Virtualisation (NFV); Virtual Network
Functions Architecture

32. Summary
●The objective in NFV is to build an automated standard-based cloud infrastructure for
creating communication services.
●ETSI is leading the NFV standardisation.
●Operators are also doing partial reference implementations such as Telefonica’s
OpenMano for management and orchestration.
●Many vendors and operators are participating into OPNFV work, which aims to build a
full reference stack for operator NFV.
●Current favourite for Virtualised Network Function Infrastructure (VNFI) is OpenStack,
which provides also basic management and orchestration (MANO) components such as
Heat.
●Some parts and objectives of the NFV concept may feel utopian, but work is constantly
being done to fill the gaps.
●NFV infrastructure and VNFs are already being deployed for customers even if those
components do not yet have all the features NFV concept promises.