First, I welcome you to the new Ericsson Technology Review. For some months now, we have been working on how to continue to deliver our in-depth technical insights this journal is renowned for, but also how to offer a broader perspective on technology developments in ICT. So here it is... I am delighted to be able to share some of my thoughts and the stories of Ericsson experts – their perspectives, concerns, and insights on advancements being made in technology. Perhaps the most obvious change we’ve made is the name of the journal. As industries merge, overlap, and collaborate more, we find ourselves changing too. I daresay the situation is the same everywhere. Today, Ericsson’s experts have different sets of skills compared with just a few years ago. Our customers also have different problems: subscribers are more demanding, and technology is more complex as it weaves its way deeper into the fabric of our lives. Some of the people I have conversations with today work in businesses that didn’t exist, even a couple of years ago. So, in an attempt to clarify what this journal is about (reviewing technology), we added the word technology to its name. To our long-standing readers, I would like to emphasize that the fundamental nature of our content – in-depth analyses of specific technologies, their consequences and benefits – hasn’t changed. The biggest change comes in the form of a new technology trends section. As the CTO of a global ICT player, I am in the fortunate position of hearing about all kinds of innovations that are shaping our industry, and I get to hear them from the multiple perspectives of many different experts. And while technology development often follows an innumerable set of investigation paths, some of them tend to stick out. So, together with a couple of Ericsson experts, I have highlighted the five trends that I believe all of us in ICT should keep an eye on in the coming year. I'd say that virtualization, network slices, more data, more mobile, security, and billions of things are today's primary drivers in ICT. Otherwise, it’s business as usual... Every month, we publish a new article online. Perhaps not surprisingly, 5G is on the agenda, including a vision for the core network, how transport networks will need to evolve, and how 5g will enable remote control. We’ll round off the year with some insights into cryptography and designing secure algorithms.

1. xxxx ✱
#01, 2015 ✱ Ericsson technology review 1
C h a r t i n g t h e f u t u r e o f i n n o v a t i o n v o l u m e 9 2 | 2 0 1 5 — 0 1
WI-FICALLING
EXTENDINGVOICE
ANDVIDEO
OVERLTE
Review
TECHNOLOGYTRENDS
thelatestinICT
fromthecto
RADIOACCESSAND
TRANSPORTnetworks
SHAReINFORMATION
Ericsson
Technology

2. ✱ xxxxx
2 Ericsson technology review ✱ #01, 2015

3. xxxx ✱
#01, 2015 ✱ Ericsson technology review 3

5. #01, 2015 ✱ Ericsson technology review 5
contents ✱
Mobile phonesOther devices
Wireline devices
OpenStack as the API framework
for NFV: the benefits, and the
extensions needed
Network Functions Virtualization (NFV) offers a
flexible and scalable way to deliver and deploy
Virtual Network Functions (VNF) services. Use of
virtualization and cloud computing is becoming
increasing popular as these techniques can
dramatically reduce time-to-market. However, the
transformation to VNF services and deployment
scenarios needs an API framework – and Open-
Stack is a suitable candidate. But is it enough, and what
improvements are needed?
(Originally published on April 2, 2015.)
Wi-Fi calling — extending the
reach of VoLTE to Wi-Fi
Using untrusted Wi-Fi to carry voice and video
communication is an opportunity to extend current
voice and video calling over lte (volte/
vilte) services in, for example,
indoor locations where cellular
coverage may be spotty.
Closely aligned with volte
architecture, Wi-Fi calling
supports mobility between
lte and Wi-Fi accesses.
(Originally published on
January 30, 2015.)
Design, architects, and complex
communication systems:
painting the bigger picture
Modern communication systems are complex, and
not just at the system level. Today’s systems are
designed collaboratively, taking the viewpoints of many
stakeholders into consideration, and so
complexity also arises at the
organizational level. Good
systems design has become
a significant factor for cost
control.
(Originally published on
May 13, 2015.)
Gearing up
support
systems for
software
defined and
virtualized
networks
The global communication
infrastructure has created a new
market of digital services in which people
and organizations can expose digital assets,
which can be rapidly combined with partner
assets to create new, more useful, and more
interesting services. But, to capture the
digital market opportunity, both telecom
networks and support systems – OSS/BSS –
need to gear up.
(Originally published on June 5, 2015.)
Setting the future media
services architecture
Many industries are undergoing
transformation, moving away from
physical products and communication
to virtual products and massive
digitalization. The benefits of an ICT
transformation that takes advantage of
commercially available IT systems, networking
equipment, and cloud-based
services are many. The media
industry in particular stands
to benefit greatly. As we
move deeper into the
Networked Society,
media production and
consumption will take
on a more prominent
role in shaping
requirements related
to network design and
performance.
(Originally published on
February 24, 2015.)
Radio access and transport
network interaction — a concept
for improving QoE and resource
utilization
By adopting a holistic
approach to network architecture, one that
enables the radio and transport domains to
share information, proactive measures to
avoid congestion can be put into place, to
increase the number of users at or above the
desired QoE level.
(Originally published on July 3, 2015.)
Technology trends
When it comes to technology,
relentless and continuous
development remains a
constant expectation.
Within this context, certain
significant shifts and
opportunities — or technology
trends — have a tendency to
stick out.
18
32
29 62
52
44
08

6. 6 Ericsson technology review ✱ #01, 2015
E r i css o n
T e c h n o l o g y
R e v i e w
Bringing you insight into
some of the key emerging innovations
that are shaping the future of
information and communications
technology. Our aim is to encourage
an open discussion on the potential,
practicalities and benefits of a
wide range of technical developments,
and help provide an insight into what
the future has to offer.
ADDRE S S
Ericsson
SE-164 83 Stockholm, Sweden
Phone: +46 8 719 00 00
PUBLI S HING
All material and articles are published
on the Ericsson Technology Review
website: www.ericsson.com/ericsson-
technology-review.
Additionally, articles are
available through the Ericsson
Technology Insights app,
which is available for Android and iOS
devices. The download links
are also available on the Ericsson
Technology Review website.
PUBLI S HER
Ulf Ewaldsson
EDITOR
Deirdre P. Doyle
deirdre.doyle@sitrus.com
TE C HNOLOGY
TREND S
Kristina Gold (Ericsson)
ART DIRE C TOR
Kajsa Dahlberg (Sitrus)
TE C HNI C AL
ILLU S TRATION S
Claes-Göran Andersson
cg@cga.se
ISSN:
0014-0171
Volume: 92, 2015

7. #01, 2015 ✱ Ericsson technology review 7
editorial ✱
First, I welcome you to the new Ericsson Technology
Review. For some months now, we have been
working on how to continue to deliver our in-depth
technical insights this journal is renowned for, but also
how to offer a broader perspective on technology
developments in ict. So here it is...
I am delighted to be able to share some of my
thoughts and the stories of Ericsson experts – their
perspectives, concerns, and insights on advancements
being made in technology.
Perhaps the most obvious change we’ve made
is the name of the journal. As industries merge,
overlap, and collaborate more, we find ourselves
changing too. I daresay the situation is the same
everywhere. Today, Ericsson’s experts have
different sets of skills compared with just a few
years ago. Our customers also have different
problems: subscribers are more demanding,
and technology is more complex as it
weaves its way deeper into the fabric
of our lives. Some of the people I
have conversations with today
work in businesses that didn’t
exist, even a couple of years ago.
So, in an attempt to clarify what
this journal is about (reviewing
technology), we added the word
technology to its name.
To our long-standing readers, I would
like to emphasize that the fundamental
nature of our content — in-depth analyses
of specific technologies, their consequences and
benefits — hasn’t changed.
The biggest change comes in the form of a new
technology trends section. As the cto of a global ict
player, I am in the fortunate position of hearing about
all kinds of innovations that are shaping our industry,
and I get to hear them from the multiple perspectives
of many different experts. And while technology
development often follows an innumerable set of
investigation paths, some of them tend to stick out.
So, together with a couple of Ericsson experts, I have
highlighted the five trends that I believe all of us in ict
should keep an eye on in the coming year. I'd say that
virtualization, network slices, more data, more mobile,
security, and billions
of things are today's
primary drivers in ict.
Otherwise, it’s
business as usual...
Every month, we
publish a new article
online. Perhaps not
surprisingly, 5g
is on the agenda,
including a vision for
the core network,
how transport networks will need to evolve, and
how 5g will enable remote control. We’ll round off
the year with some insights into cryptography and
designing secure algorithms.
You can access all of our content on the new
Ericsson Technology Review home page, download
the articles to your mobile device through our Ericsson
Technology Insights app, or read them on SlideShare.
All links can be found on our new website at: www.
ericsson.com/ericsson-technology-review.
embracing relentless
change in ict
Ulf Ewaldsson
Senior Vice President,
Group CTO, and head
of group function
technology
90% of the
world’s population
over 6 years old
will have a mobile
phone by 2020*
* Ericsson Mobility Report, 2015

8. 8 Ericsson technology review ✱ #01, 2015
✱ Better customer experience
Radio access and
transport network
〉〉 Stefan Dahlfort
Shahryar Khan
Jonas Rosenberg
Anton Smith
Shuo Yang
Mats Forsman
and Tomas Thyni
a concept for improving QoE
and resource utilization
In today’s networks, radio access and transport are largely unaware of each
other, but are inherently related, as impaired conditions in either domain
can adversely affect user experience. As QoE has a significant impact on
customer satisfaction and customer retention1, potential improvements in
user experience are of key business interest.
interaction
t o i m p r o v e o v e r a l l QoE, a holistic
approach to network architecture is vital —
one that takes into consideration conditions
in both radio and transport domains, and that
results in the ­creation of proactive measures
for preventing congestion.
Theconceptofran transportinteraction(rti)
introducescoordinationbetweentheradioand
transportdomains,andaimstoprovidetheholistic
approachneededtoimproveQoE.Inthisarticle,the
principlesandbenefitsofthisconceptaredescribed,
asisthehigh-levelsetofbuildingblocksforthe
rti solution,andthewholeisexemplifiedwitha
fewselectedusecases.Insomeway,rti canbe
viewedasanexampleofcross-domaininteraction2
.
Specifically,thisarticleaddressestheradioaccess
andtransportcomponentsoftheoverallnetwork.
Whythecallfornewtechnology?
Theincreasingglobaldependenceonmobile-
networkingservicesiscausingcongestionin
networks.Therateofuptakeofmobilebroadband,
forexample,issettorisesignificantly:in2014,total
globalsubscriptionstopped7 billion,whichareset
toriseto9.2 billionby20203
.Andso,congestion
issueswillcontinuetobeamongthemoresignificant
factorsthatimpactusersatisfaction.
Whilerapiddevelopmentsintechnologyand
communityfoundations,suchasexploitationofnew
frequenciesandconceptsforenergyconservation,
areshapingnextgenerationnetworks4
,perhaps
themostsignificantchangefactortodayishow
societyandindividualsareusingmobile-broadband
services.Thecurrentdemandforsuchservicesand
capacityisonanupwardcurvethatshowsnosignsof
levelingoff.

9. #01, 2015 ✱ Ericsson technology review 9
Better customer experience ✱
Asnetworkingserviceslikemobilebroadband
relyontheentirenetwork—includingradioaccess,
thetransportnetwork,datacentersandtheglobal
internet—toensureexcellentQoE,applyinga
holisticapproachtonetworkarchitectureiscrucial.
Asmoreinformationbecomesavailable,related
tosaylocation,magnitude,origin,andduration
oftraffic,theeasieritbecomestomitigateQoE
impairment.However,asradioandtransport
domainsdonotsharemuchinformation,theyare
largelyunawareofeachother.
Consequently,animpairmentinonedomainmay
gounnoticedbytheother,makingitdifficult—or
evenimpossible—tooptimizeresourceusageand
takethenecessaryactionstoavoidthecongestion.
Thetermimpairmentisusedtoindicateany
sourceofQoEdegradationrelatedto,forexample,
trafficcongestion,whichresultsinpacketdelay,
delayvariationsordroppedpackets.Typically,
sourcesofdegradationtendtobeinterdependent
andareoftenanindicationthatnetworkresources
areoverutilized.
Forexample,trafficcongestionmayoccurinthe
transportnetworkatcertaintimesandlocations,
andforgiventypesoftraffic.Theradioaccessand/
orthetransportdomaincouldtrytomitigatesuch
congestionbutthelackofinformationsharing
betweenthemmakesthistaskcomplex,andinsome
casesimpossibletosolve.
Notaone-to-onerelationship
Thetransportnetworkcarriestraffictoandfrom
differenttypesofradiodomainanduser.Typically,
thetransportnetworkmapsthistraffictothe
relativelysmallnumberofQoSclassesusedby
transportnetworkoperators.
Asaresult,thetransportnetworklacksthe
necessarygranularitytodifferentiatetraffic,leading
tosuboptimalnetworkutilization,whichhasan
impactonQoE.
Encryptioncomplications
Toimproveitsunderstandingofthetraffic
situation,thetransportdomaincanusedeeppacket
inspection(dpi)togetmoreinformationabout
granularflowsatrouteringressports.Forexample,
thetunnelendpointidentifier(tied)includedin
thegprs TunnelingProtocol(gtp)5
canbeusedto
encapsulatevariousQoSbearers.However,forthis
tobeuseful,thetransportnetworkdomainneedsto
knowwhattypeoftrafficisaddressedbythespecific
tied.Unfortunately,whenencryptionlikeipsec6
isapplied—anapproachthatiswidelydeployedin
lte networks—thetied cannotbereadusingdpi.
Inadequatemeasurements
Anotherpossiblewaytoimprovetheoverall
understandingoftrafficisfortheradiodomain
toaccessthetransportdomain’sperformance
characteristics.Thiscanbeachievedthrough
passiveoractivemetrics,whichcanbeaccessed
through,forexample,applicationofthetwo-way
activemeasurementprotocol(twamp)7
.
However,metric-basedmethodsmaybetooslow
toreacttotrafficimpairmentsthatarehighlytime
dependent.Inaddition,whilemeasurement-based
approachesareusefulforprovidingend-to-end
characteristics,theyfallshortofprovidingthe
informationneededtopinpointcongestion.
Themeasurementapproachisconsequently
inadequateforproactivenetworkoptimization,
andisfurtherinhibitedbythefactthattheradio
Terms and abbreviations
be: best effort |dpi: deep packet inspection |ecmp—equal cost multipath |gtp—gprs Tunneling Protocol |
hqos—hierarchical QoS |lag—link aggregation group |mme—Mobility Management Entity |mpls—multi-protocol
label switching |pcrf—policy and charging rules function |qoe—quality of experience |ran—radio-access
network |rat—radio-access technology |rnc—radio network controller |rti—ran transport interaction |sdnc—
software-defined networking controller |s/pgw—pdn gateway |teid—tunnel endpoint identifier |
ue—user equipment

10. 10 Ericsson technology review ✱ #01, 2015
✱ Better customer experience
Transport-unaware radio RAN-unaware transport
Am I aware of congestion in
the transport path?
=> QoE impact
Am I aware of granular
RAN flows?
=> non-optimized transport paths
RAN Transport
Transport-aware
RAN
RAN-aware transport
Transport path load
and capacity
Granular RAN
traffic treatment
Optimal distribution of
RAN flows to help avoid
congestion in transport
Better utilization of
available diverse paths
Reduction in network
state and energy waste
Figure 1
rti problem (left)
and opportunity
(right) formulations
Figure 2
rti: a phased approach
to congestion mitigation
Proactive
congestion
avoidance
1 Redistribute
Reroute
Congestion
handling
(if congestion
avoidance fails)
2 Fairness
RAN
Holistic network configuration
Transport

11. #01, 2015 ✱ Ericsson technology review 11
Better customer experience ✱
domainisagnosticofthetransportdomain’s
capabilitytoself-optimize—andsoattemptstosolve
acongestionissue(basedonobservedconditions)
maybefutileiftheproblemhasalreadybeen
addressedbytransport.
Connectingradioandtransport
Giventhelimitationsofexistingtechnology,devising
explicitinteractionbetweenthetwo—radioand
transport—domainsisamoreappropriatemethod
thatofferssignificantadvantages.
Anumberofmodelscanbeusedtocreatethe
connectionbetweenradioandtransport,such
asapeer-to-peerorclient-servermodel(withor
withouthierarchies).Thesolutiondescribedin
thisarticleusesaninformation-sharingmodelthat
boastsonesignificantfeature:eachdomaincontrols
theinformationthatitshareswiththeother,and
dictatesexactlywherethatinformationmaybe
used.Significantly,thedecisiontoshareorrequest
informationneverresultsinafeedbackloop,as
explicitinformationsharingreducesorremovesthe
occurrencesoffailuretomitigateagainstcertain
impairmentconditions.Therti problemand
opportunityformulationissummarizedinFigure 1.
Thedescribedapproach
Solvingcongestion,asillustratedinFigure 2,isa
two-stepprocess,whichfirstaimstoproactively
avoidcongestionscenarios,andthento
handleanyunavoidablecongestion.
Proactivelyminimizingcongestioncanbe
achievedbyoptimizingtheuseofavailable
resourcesinboththetransportandradio-
accessdomains.Optimizationinturnusestwo
methods:redistributionandrerouting.Inthecase
ofredistribution,theradiodomainmovestraffic
around(whenpossible),effectivelyload-balancing
inanoptimalwayacrossthebackhaultransport
network.Inthecaseofrerouting,thetransport
networkusesanumberoftechniques,likesdn-
basedtrafficengineering,tomakebetteruseof
availablealternatepaths.
Mechanismscanbeappliedtorelieverelative
starvationamongthevariousradio-access
technologies(rats).Forexample,byapplyinga
fairnessmechanism,thetransportnetworkcan
useinformationreceivedfromtheradionetworkto
preventstarvationbetweendifferentradioaccesses
duringcongestionconditions.
Usecasesandbenefits
Exampleusecase1:
proactivecongestionavoidance
Asthenumberofconnectedmobiledevicesand
bandwidthconsumptionperuserrises,theriskof
introducingtemporarycongestionsinthetransport
networkincreasesaccordingly.Butinmanycases,
congestionoccurrencesaretemporary,andso
averagebandwidthutilizationinthetransport
networktendstobemoderate.
Thebestsolutionforcaseswhere­sizable
QoEdegradationsoccuristoeithermitigateor
circumventcongestion.Thisfirstexampleusecase
—proactivecongestionavoidance—addresseshow
informationprovidedbytransporthelpstheradio-
accessdomaintomakehandoverdecisionsthatare
moreholisticinnature.
Tomaintainconnectivitybetweentheran and
aue,traditionalhandoverdecisionsaremadeon
thebasisofradiosignalquality,whichisassessed
continuously.Handovertoanothercellistriggered
whenradioconditionsbecomemoreadvantageous
inaneighboringcell.However,theleveloftransport
congestionineachcellisnotpartofthehandover
decision-makingprocess.
Toincreaseavailability,andtobeableto
propagatetrafficovermultiplepaths,mobile
transportincludesadegreeofredundancyinthe
metroaggregationnetwork—typicallyinterms
ofdifferentringornecklacetopologiesthatuse
protectionschemasandlinkaggregationgroups
(lags).However,closertotheradioaccess,
transportnetworkstendtobebuiltinanon-
redundanttreeshapeanddonotofferpathdiversity.
Congestionoftenoccursintheaccessaggregation
partofthenetwork(seeFigure 3),butmayalsoarise
inthemetroportion,wheremobiletrafficmerges
withfixedresidentialandbusinesstraffic.Hop-by-
hoppathcharacteristicmeasurementsperformed
inthetransportnetworkcanbeshared,providing
theradioaccesswithknowledgeabouttransport

12. 12 Ericsson technology review ✱ #01, 2015
✱ Better customer experience
Congested link
Agg
Agg
Agg
Agg
Agg
Agg
PE
PE
RNC
CSR
CSR
CSR CSR
CSR
CSR
CSR
CSR
CSR
CSR
CSR
CSR CSR
xGW
No congestion
LAG
10 GE 10 GE
20 GE
20 GE
Agg
RBS
RBS
RBS
RBS
Figure 3
Example use case: proactive congestion
avoidance

13. #01, 2015 ✱ Ericsson technology review 13
Better customer experience ✱
BE flows
Access network
BE flows
HQoS
threshold
RAN flows
RAN flows
Agg
20 GE
High load
High load
Low load
Low load
Low load
20 GE
Agg
Agg
Agg
Agg
Agg
Agg
PE
PE
RNC
CSR
CSR
CSR CSR
CSR
CSR
CSR
CSR
CSR
CSR
CSR
CSR CSR
xGW
LAG
10 GE 10 GE
Agg
RBS
RBS
RBS
Figure 4
Example use
case: optimized load
balancing
Figure 5
Example use case:
fairness

14. 14 Ericsson technology review ✱ #01, 2015
✱ Better customer experience
congestion.Thiscongestioninformationcanbeused
toenhancethehandoverprocedure.
Toavoidhandovertoaneighboringcellwherethe
radioaccessisconnectedtoacongestedtransport
path,informationabouttransporttopologyis
needed.Thisinformationenableshandoverto
neighboringcellsthatareconnectedtouncongested
transportpaths.
Theprobabilityofaneighboringcellbeing
connectedtoanuncongestedtransportpath
correlatestothesystemgainforproactive
congestionavoidance.Thelevelofsystemgain
attainableishighlydependentonhowthenetworkis
built,intermsofcelldensity,transporttopologyand
technology.Urbanareas,forexample,tendtoexhibit
highnumbersofcellswithinreachofaue.Asa
result,thepotentialforimprovedsystemgainishigh
insituationswherethecellshavediversetransport
paths.
Holistichandoverdecisionsarethusformed
onthebasisoftransportcongestiontogether
withthetypicalsignalstrengthandneighboring
cellinformation—allofwhichareweighted.
Byincludingtransportutilizationinformation,
moreinformedhandoverdecisionscanbemade,
whichtogetherwithanabstractionoftherelevant
transporttopologyenablesacelltofindasuitable
neighboringcelltohandoverto.
Thebenefitsofrti forthisusecasecanbe
summarizedas:byusingcongestioninformation
fromthetransportdomain,theradiodomaincan
placeusertrafficoptimallyacrossradiocells,from
acombinedpointofviewofradioandtransport
characteristics.Figure 3illustratesanexampleof
thisproactivecongestionavoidance,wherethe
secondmilelinkisthecongestedpart.
Onahighlevel,thebenefitforthisusecaserelates
tothenumberofadditionalusersortrafficforwhich
theQoErequirementscanbemetinrelationtothe
availableradioresources(suchasspectrumand
radioequipment).Inthiscase,rti canbeusedto
handovertrafficgeneratedbyusersinacellwith
congestedtransporttoanothercellwithinthe
coverageareathathasuncongestedtransport.As
trafficismovedawayfromthecongestedcell,rti
hasapositiveimpactonusersthatremainconnected
totheoriginalcell—usersthatcannotbehanded
overtoanuncongestedcellbecausetheyarenot
withincoveragearea,orcannotbehandedoverfor
otherreasons.Thispositiveimpactresultsfromthe
loaddropintheoriginalcongestedcellasproactive
handoveractionsaretaken.
Thepotentialgainforrti canbemeasuredbythe
increaseinusersatorabovethedesiredQoElevel
comparedwithanetworkwithoutrti.
Naturally,actuallycalculatingthegaindepends
onthespecificnetworkcaseandneedstoconsider
factorssuchastheutilizationofcongested/non-
congestedtransportandcells,userbandwidthand
priority,anddifferenceinradioquality.
References
1. Ericsson, 2012, Why Superior Network Performance Matters, available at:
http://www.ericsson.com/news/120917_why_superior_network_performance_matters_244159018_c
2. Ericsson, 2014, Ericsson Review, Architecture evolution for automation and network programmability,
available at: http://www.ericsson.com/news/141128-er-architecture-evolution_244099435_c
3. Ericsson, June 2015, Mobility Report, available at: http://www.ericsson.com/mobility-report
4. Ericsson, 2015, Anticipating Opportunities with 5G, available at:
http://www.ericsson.com/news/150305-anticipating-opportunities-with-5g_244069647_c
5. 3gpp, ts 29.060, gprs Tunnelling Protocol (gtp) across the Gn and Gp interface, available at:
http://www.3gpp.org/DynaReport/29060.htm
6. ietf, 2005, RFC 4301 Security Architecture for the Internet Protocol, available at:
https://tools.ietf.org/html/rfc4301
7. ietf, 2008, RFC 5357, A Two-Way Active Measurement Protocol (twamp), available at:
https://tools.ietf.org/html/rfc5357

15. #01, 2015 ✱ Ericsson technology review 15
Better customer experience ✱
Exampleusecase2:
optimizedload-balancing
Thisusecaseaddressestransport,andhowit
canmakebetteruseofavailableresourcesby
obtainingrelevantinformationfromradio.As
mentioned,thetransportdomainlacksgranularity,
andsotheproposedsolutionistoannouncetraffic
informationtothetransportnetworkinsucha
waythatexistingstandardizedimplementations
ofthegtp oripsecprotocolsrequirenochange.
Theadditionalinformationallowsthetransport
networktooptimallyload-balancetrafficoverequal
costmultipaths(ecmps)oralag.Inaddition,the
proposedsolutionwillworkequallywellfortraffic
thatisencryptedasfornon-encryptedtraffic.
Therti gainforthesecondusecaseisbuilton
theassumptionthatloadbalancingtrafficinan
optimizedfashionresultsinanoverallimprovement
ofQoEandbetterutilizationoftransportresources,
seeFigure 4.
Exampleusecase3:fairness
Today,transportnetworkscannotdistinguish
betweenbest-effort(be)trafficoriginatingfrom
differentradioaccesstypes.Theradio-access
domainhasmoregranularQoSprofiles,but
mappingthemontothetransportdomainwill
significantlyincreasethecomplexityoftheQoS
solutionforthetransportnetworkoperator.
Theresult:be-markedtrafficwillexperience
thesame,sharedper-hopbehaviorforallaccess
technologies,whichmaycausestarvationofone
orseveralrats.Byinsteadexchangingtraffic
informationandbandwidthratios,thetransport
networkcanpreventun-fairnessbyrate-limiting
selectedtraffictypes.Anexampleofthisapproach
forfairnessisillustratedinFigure 5,whichshows
atraditionalmethodthatwillexhibitunfairness,
andanenhancedrtimethodthatensuresfairness.
rtibenefitandrtigainsforthisusecasecanbe
formulatedinthesamewayasfortheprevious
cases.
Thebuildingblocks
Basedontheexampleusecases,Figure 6illustrates
thebuildingblocksoftherti solution.Themain
buildingblocksaregenerictocommunication
systemsandincluderadioaccess,transportandthe
packetcore.
Radioaccess
Thispartofthesystemincludesmulti-standard
mobilebroadbandsystems—suchas2g/edge,3g/
wcdma,and4g/lte (with5g cominginthefuture)
—togetherwiththeircontrollerfunctionslikernc
andbcs.
Transport
Thispartofthesystemincludesroutersand
switches(suchasip/mplsandl2)andphysical
layercomponents(suchasmicrowaveand
opticaltransport)togetherwiththeirrespective
optionalcontrollercomponents.Specificallyfor
thetransportdomain,suchanoptionalcontroller
componentisillustratedinFigure 6bythesdn
controller(sdnc).
Packetcore
Thispartofthesystemincludesconnectivityand
routing/forwardinggateways(s/pgw),multimedia
controlnodes(suchasmmes)aswellaspolicy
entities(suchasthepcrf).Asthepacketcore
containsrelativelyfewelementscomparedwith
radioaccess,scalabilitybenefitscanbegained
bysharinginformationbetweenthetransport
controllerandthepacketcore.
Specifically,rti-applicationfunctionsare
includedinradio-access,transportand,optionally,
thepacket-corenetworksinorderto:
1.gathertheinformationrelatedtoitsdomain;
2.handletheinformationflowbetweenthetransportand
radiodomains;and
3.makeintelligentdecisionsbasedontheshared
information.
Therti applicationconsistsofdistributedrti
entitiescorrespondingtotheradioaccess,transport
andcorenetworks,andoffersthefollowingbenefits:
〉〉 maximizedflexibilityandscalability;and
〉〉 utilizationoffuturetechnologies,suchasadvanced
analytics,self-organizingfunctions,and5Gmobile
broadband.

16. 16 Ericsson technology review ✱ #01, 2015
✱ Better customer experience
Summaryandconclusions
Thisarticleoutlinesthebackground,motivation,
exampleusecasesandbuildingblocksofrti —a
newconceptforsharinginformationbetweenradio
andtransportdomainstooptimizeQoE.
Byillustratingtheconceptthroughselected
exampleusecases,thegainbecomesclear.Proactive
congestionavoidance,forexample,enablestheradio
domaintomakemoreintelligenthandoverdecisions,
asitincludescongestioninformationprovided
bythetransportdomaininthedecision-making
process.Theresult:improvedQoEwiththeexisting
setofavailableradioaccessandtransportnetwork
resources.
Theotherusecases—loadbalancingandfairness
—illustratehowtheinformationfromtheradio
domainfacilitatesbetterutilizationofavailable
transportresources.Inthecaseofoptimizedload-
balancing,morefinelygrainedinformationprovided
bytheradiodomainenablesthetransportdomain
tooptimallyredistributetraffic,andtherebyensure
betterutilizationofthenetwork.Inthecaseof
fairness,theinformationfromtheradiodomainis
usedtoallocatebandwidthinip routersformobile
trafficcarriedbydifferentgenerationsfairly.For
eachusecase,anoutlineoftherti benefit
principleshasbeenprovided.
Insummary,rti isaninnovativeconceptthat
enablesasignificantimprovementinQoEformobile
usersinthecontextoftheexampleusecases.In
addition,rti enablesmoreoptimalutilizationof
networkresources.
M M MOSS/BSS
RTI domain - radio
RTI domain - transport
RTI domain - packet core
3GPP xGW PCRF
MME/S
GSN
Optical uWave RouterSDNc
3GPP
BSC/
RNC
OSS
RTI
entity
Domain
mgmt BSS
Traffic entry point
Figure 6
RTI building blocks

17. #01, 2015 ✱ Ericsson technology review 17
Better customer experience ✱
Stefan Dahlfort
◆Hasabackground
withincumbenttelecom
operatorsandlargetelecom
vendors.Hefoundedastart-
upbeforejoiningEricsson
◆ In2007asmanager
forfttxresearch.Heled
Ericsson’sresearchinthe
areaofbroadbandaccess
andtransportinSilicon
Valley2010-13,andsince
then,hehasbeenhead
ofDevelopmentUnitip,
SystemsandTechnology.
HeholdsanM.Sc.anda
Ph.D.inopticalnetworking
fromkth RoyalInstituteof
TechnologyinStockholm.
Jonas Rosenberg
◆ JoinedEricssonin2000
andiscurrentlysystems
and solution manager
at Development Unit ip,
Systems and Technology.
He is a senior specialist
in network architecture
and solutions with a focus
on strategic technologies
for orchestration and
assurance solutions in
mobile transport networks.
He holds an M.Sc. in
electrical engineering
from kth Royal Institute of
Technology in Stockholm.
Mats Forsman
◆ JoinedEricssonin1999
toworkwith intelligent
networks. Since then
he has worked within
the IP, broadband and
optical networks areas.
Today, his focus is on new
concepts for transport
within ran at Ericsson
Radio; one such concept
area is ran and transport
interaction. He holds an
M.Sc. in mathematics and
natural science from Umeå
University, Sweden.
Anton Smith
◆ Isaseniorproduct
manager for Ericsson’s
metro and backhaul
product line. He has over
12 years’ of experience in
the IP vendor and service
provider industry, including
architecture, design and
operation of production
ip/mpls networks for
mobile backhaul and triple
play services at multiple
operators. He holds a
Bachelor of Information
Science from Massey
University, New Zealand.
Shuo Yang
◆ JoinedEricssonin2009
andiscurrentlyasenior
systemdesignengineer
atDevelopmentUnitIP,
SystemsandTechnology.He
holdsanM.Sc.inelectrical
engineeringfromHarbin
InstituteofTechnology,
China.
Tomas Thyni
◆ Isanexpertintheareaof
IPandtransport networks.
A telecommunication
and network engineer, he
joined Ericsson in 2000
and has worked within the
IP, broadband and optical
networks areas. Today, he
works on new concepts
for transport in ran at
Ericsson Radio; one such
concept area is ran and
transport interaction.
Prior to joining Ericsson,
he accumulated 15 years
of experience as an IP and
transport network designer
at various network
operators.
Shahryar Khan
◆ Hasnearlytwo
decades of experience in
architecture design and
integration for multiservice
IP and transport networks
for telecom operators
and large enterprises.
He has managed diverse
roles within Ericsson,
and he recently worked
as a principal solution
architect for IP and SDN
in Engagement Practices
for tier-1 customers. At
present, he is working
as an expert and chief
architect in multiservice
ip and transport networks
in Development Unit ip,
Systems and Technology
(Sweden).
theauthors

18. 18 Ericsson technology review ✱ #01, 2015
✱ Illustrative architecture
The task of building, maintaining and developing communication systems
is complex. The level of complexity rises as the number of stakeholders
involved in creating these systems increases.
As a result, vendors, system integrators, operators — and increasingly
their business partners — need to communicate more. And so, besides
understanding how their own systems work, modern designers and business
developers need to grasp how other stakeholder systems work, and to have
an appreciation of the various possible approaches to architecture design.
〉〉 Ulf Olsson
Toni SiljamÄki
Francis Bordeleau
bigger
picture
Design, architects, and
complex communication
systems: Painting the

19. #01, 2015 ✱ Ericsson technology review 19
Illustrative architecture ✱
The ability to grasp complex structures can be
greatly facilitated by using visualization tools.
A common illustration approach enables
modern system architects to share design
concepts. Support tools that help designers
to maintain, communicate and discuss
structures are a fundamental part of modern
systems architecture. This article presents
Ericsson’s methodology for developing such
support tools.
Designing the best system
e x p e r t s w h o buildandmaintainvery
largesystemsarecontinuouslylookingforwaysto
increaseproductivityandimprovequality.Raising
thelevelofabstractioninvolvedinsystemdesign
isonewayofdoingthis.Itreleasesdesigners(and
others)fromtheneedtokeeptrackofanever-
increasingnumberofdetailsanddependencies—a
numberthatrisesexponentiallywithsystemsizeand
complexity,productrangeandstakeholdercount.
Model-basedengineeringhasbeenused
successfullyformanyyearstoachievethebest
combinationofcomputepoweranddesign
knowledge.Tocapturethestructureofasystem,this
methodologyusesalogicalmodelofaggregation
anddependencies—whicharevisualizedina
graphicalformat.Inthisway,proposedmodelscan
bevalidatedandmodifiedeasily.
Owingtothecomplexityofmodern
communicationnetworks,systemsarchitecture
isoftensplitintovariousdomains,eachwithan
assignedgroupofarchitects.Inadditiontodesigning
andmodelingtheirrespectivedomains,these
architectsareresponsibleforensuringthatallof
theirpeershaveacommonunderstandingofthe
domaininterfacesandfunctionalallocations.
Model-basedengineeringoffersthelevelof
person-to-personinformationtransferneededto
designlarge,modern,complexsystemsefficiently.
However,designingmodernsystemsrequiresa
toolset:onethatiscapableofbeingadaptedtoawide
rangeofconstantlyevolvingdemands,posedby
manydifferentstakeholders—includingproducers,
systemsmaintainers,andtheactualusersofthe
designs.
Thewantedoutputisacomplete,coherent,
consistentandrevisablenetworkdescription—one
thatenablesthenetworktoevolveinacontrolled
manner,addressnewchallenges,andabsorbnew
technologies.
Buttocreatethebestsystem,facilitatingamutual
understandingamongarchitectsisonlyonekey
ingredient.Architectsalsoneedasetofcompanion
tools—toolsthatcan,forexample,helpthemto
validateproposedmodels,analyzethepotential
impactofsuggestedchanges,detectinconsistencies,
andeasetheimplementationprocess.
Supporttoolsforsoftwareandhardwaredesign
haveexistedfordecades,but,unfortunately,they
donotaddresshowtobridgethegapbetweenthe
abstractrepresentationsusedbydesignerstomodel
therealworld,anddetailedones,whereeveryaspect
ofaprocessora­structuremustbedescribedinfullto
enableautomation.
Inthecontextofnetworkprogrammability,
theabilitytobridgethisgapbecomesevenmore
significant.Identifyingthecapabilitiesthatcan
beinvoked,anddetermininghowtocontrolthem
fromoutsidethenetworkproper,becomesmore
challengingasthelevelofautomationrises.
TheapproachwetooktodeveloptheEricsson
toolsetdemonstrateshowopen-sourcetechnology
Termsand abbreviations
css—Cascading Style Sheets | dsl—domain-specific language | dsml—domain-specific modeling language |
egit—Git with Eclipse | emf—Eclipse Modeling Framework | Git—open source control model | gmf—Graphical
Modeling Framework | nwa dsl—network architecture dsl | ocl—Object Constraint Language |
PaaS—platform as a service | svg—Scalable Vector Graphics | sysml—Systems Modeling Language | ui—user
interface | uml—Unified Modeling Language | Xtext—framework for developing programming languages

20. 20 Ericsson technology review ✱ #01, 2015
✱ Illustrative architecture
RAN EPC
S1 Gi ISC
IMS
core MTAS
OSS/
BSS
M
IMS
client Mb
Gm
Mw
Cx ISC
Mb
MrIq
AGw MRF
MTAS
S/I-
CSCFP-CSCF
HSS
Function - IMS core
Figure1
Top-level network diagram
Figure2
Exploring a function

21. #01, 2015 ✱ Ericsson technology review 21
Illustrative architecture✱
enablesdevelopmentsinmodelingtechnologytobe
addedastheybecomeavailable.Collaboration—
withinthetelecomindustry,andwithotherindustries
facedwithsimilarsystemdesignchallenges—has
beencrucialfactorindevelopingatoolsetthatcan
servemodernmulti-stakeholderenvironments.
Primaryusecase:
modelingnetworkarchitectures
Butwhatisnetworkarchitecture?Onedefinition
mightbe:thesumofallthecomponentsneeded
foroperatorstoproducetheirservices.Sucha
definitionincludesanumberofaspects:functional
descriptions,implementationcomponents,
products,topologicalarchitecture,aswellas
businessandresponsibilityrelationships.
Functionaldescriptions
Asystemcomprisesasetoflogicalfunctionsand
howtheyinterrelatethroughlogicalinterfaces.
Deconstructingasystemintoitsvariouselements
facilitatesanunderstandingofhowthesystem
works.Modernmodelsuserecursiontosimplify
systemsintonetworkelementsandcomponent
partstoapointwhereapersonwithsomesystem
knowledgeunderstandsthem.
Ideally,architecturedesignshouldbedecoupled
fromimplementation.Inpractice,variantsofa
systemtendtoexisttoaddresstheneedsofdifferent
deploymentcontexts.Systemscan,forexample,be
providedonadedicatedplatform,throughacloud
infrastructure,orusingPaaS.Inasense,thehigh
levelarchitectureisthevariantthatisstillvalidafter
asystemhasbeensignificantlyre-implemented(for
instance,afterachangeofplatformtechnology).
Implementationcomponents
Logicalfunctionsareagreatwaytoexplainwhat
asystemdoes,andtosomedegreehowitdoesit.
However,todeliveractualproducts,implementation
componentsthatcorrespondtologicalfunctions
areneeded.Implementationcomponentscanbe
combinedandreusedtoproducethebehavior
describedbythelogicalfunctions.Sometimes,a
directcorrelationexistsbetweenlogicalfunctions
andimplementationcomponents,butthis
relationshipistypically
many-to-many.
Alogicalfunction
canbeexecutedby
severalimplementation
components,although
reusabilitygoalssuggest
thatthisshouldonlybe
thecasewhencertain
constraints,suchaschoice
ofexecutionenvironment,createaneedforseveral
implementations.Animplementationcomponent
canberesponsibleforimplementingseverallogical
functions,andagain,sounddesignprinciples
suggestthatthisshouldbethecaseonlywhen
functionsaretightlycoupled.
Products
Productsareaggregatesofhardwareand/or
softwarecomponents.Extendingthemodel
fromlogicalfunctionsthroughimplementation
componentslinksthelogicalarchitecture—which
doesnotchangeifthefunctionalrequirementsare
stable—toproductlifecyclemanagement(including
marketadaptations),withitsprocessesandtools.In
avirtualizedenvironment,productswill,toalarge
degree,beimplementedasprepackagedvirtual
machines(orincreasinglyusingthecontainer
concept,asexemplifiedbyDockercontainers1
),
althoughoptimizedhardwareandsoftware
componentsusedinhigh-performanceelementsofa
radiobasestation,forexample,willcontinuetoplay
asignificantroleindesigningthebestsystem.
Topologicalarchitecture
Intelecoms,systemtopology—theabilityto
understandwherefunctionalityisbestdeployed
—isvitalforcreatingthebestsystem.Telecomsis
essentiallymotivatedbytheneedtoconnectdevices
separatedbydistance.Mobilenetworksneedto
connectdevicesastheymoveabout,andsosystems
needtobedesignedtocopewitharangeoftraffic
patterns.Asaresult,topologybecomeshighly
relevant,especiallywhendesignparametersinclude
latency,resilience,interconnectpoints,compute
powerorcost.
bridging the gap
between the abstract
representations of the
real world, and details
to enable automation

22. 22 Ericsson technology review ✱ #01, 2015
✱ Illustrative architecture
Forvirtualizedscenarios,thelocationofa
softwarecomponentisnotsetatdeploymenttime,
butisinsteadadynamicparameterdetermined
bytheoperationalsystem.Determininglocation
isacomplexcloud-managementprocess,onethat
requiresrapidsystemresponseandahighdegree
ofautomation.Modelingsuchsystemprocessesis
essentialtoensurerealisticautomation.Forexample,
tomeetlowlatencyrequirements,somenetwork
componentsmayneedtobedeployedclosetoeach
other,whileredundancyrequirementsmaydictate
thatcertainnetworkcomponentsbekeptapart.
Responsibilityrelationships
Systemsneedtobedescribedintermsofthe
functionalityeachbusinessentity(operator,partner,
platformprovider,devicemanufacturer,content
provideroruser)isresponsiblefor.Suchdivision
ofresponsibilitiesisnotnecessarilylimitedtothe
relationshipsbetweenseparatelegalentities,but
canalsobeappliedtounitswithinthesamelegal
entityorcompany.Keyresourceslikeaccessand
corenetworks,computinginfrastructureand
databasesmustbeprotected.Atthesametime,the
paceofbusinessrequiresthatnewservicescanbe
developedandlaunchedwithouthavingtowaitfor
traditionalsystemintegrationtobecompletedor
forthemassiveamountoftestingtobeconcluded.
Networkarchitecturemodelingplaysakeyrole
inidentifyingthekeyinterconnectionpoints,
highlightingtheinterfacesthatcanbedefinedand
thusprotectedasexposableservices.
Businessrelationships
Thebusinessrelationshipincludeshowworkflows
andcommercialprocessesaredescribed,how
theytouch,andhowtheyhelptodefinethelogical
functionsinthesystem.
Allaspects,fromfunctionaldescriptionstobusiness
relationships,arelinked.Thecomplexjobof
establishingandmaintainingtheselinksisacritical
factorbehindtheneedforformalmodelingand
abstractioncapabilities.
Perhapsthemostimportantbenefitofaformal
modelbehindthegraphicalrepresentationofa
systemisthatitallowsthearchitecturetoevolvein
acontrolledway.Theabilitytoanalyzeamodelfor
completenessandconsistency,andthecapabilityto
carryoutimpactanalysisonproposedchanges,are
keyfactorsintheneedformodel-basedengineering.
Graphicalrepresentation
ofthesystem
Figure 1showsatypicalnetworkarchitecture
illustration.Itconveysthemainpurposeofasystem
throughasetofinterconnectedlogicalfunctions.
Eachfunctionisportrayedasanicon,whichconveys
thefunction’sprimarypurpose.Color-codinghelps
tosupporttheassociationoffunctionstonetwork
areas,butcolorisalsousedtoshifttheviewer’sfocus
tospecificpartsofthesystem.Theelementsshown
inFigure 1areexamplesofnetworkareas—main
groupingsoffunctionality.
Besidesfunctionalelements,connections
areasignificantfeatureof­network-architecture
diagrams,astheyillustratethedirectrelationships
betweenfunctionalelements.
Figure 2illustrateshowanetworkelement/
functioncanbedescribedindetail.Thebounding
boxrepresentsthefunctionatahigherlevelof
abstraction.Eventhoughtheelementsoutsidethe
boxarefunctionsdefinedbyothernetworkareas,
theyareincludedastheinformationcarriedover
theinterfacehelpsthereaderunderstandtherole
ofthefunction,anditsrelationshipswiththerestof
thesystem.Byadheringtotheprincipleofneed-to-
know,contextisnotlostastheviewerdrillsdown
fromoneleveltothenext.
Thisneed-to-knowprincipleisfundamentalto
Ericsson’stoolset,whichcancreateahierarchyof
diagramsthatshowjustwhatthereaderneedsto
understand:inotherwords,asystemthatrenders
illustrationswiththemainstructuresandthe
correctlevelofdetailwithoutbeingclutteredwith
­unnecessaryinformation.
Detailsareconveyedthroughrecursive
decompositionofthelogicalfunctionsintosub-
functions—aconceptthatisillustratedinFigures 1
and2.Toillustratetheprincipleofrecursive
architecturedescent,Figure 3showshowalogical
functioncanberendered.

23. #01, 2015 ✱ Ericsson technology review 23
Illustrative architecture ✱
P-CSCF
Cx ISC
Mw
Mr
MRF
MTAS
Media
handling
HSS
Registrar
SIP
routing
Function - S/I-CSCF
Figure3
Drilling down into a logical
function

24. 24 Ericsson technology review ✱ #01, 2015
✱ Illustrative architecture
Thesearchitecturediagramsarethetoolset’s
graphicaldescriptionofthelogical,multilevel
structureofthenetworkarea(beingdescribed).
However,formalrepresentationisalsorequired.
Figure 4showsaformal,tree,representationof(a
partof)thesamemodel.
Theformalmodelmaycontainprotocol
definitions,whichconsistofsignalsandtheir
parameters.Functionalcomponentscanbe
associatedwithsuchprotocols,anddetailhowthey
interactwitheachother.Sequencediagrams,like
theoneshowninFigure 5,arecreatedusingthe
setsofsignalsavailableintheprotocols,andaidthe
understandingofhowasystemworksbyadding
behaviortothearchitecture.
Inlinewithgooddesignprinciples—
simplificationwherepossible—recursivedescent
isalsoappliedtosequences,sothatseveral
subsequencescanbeabstractedintoablock,which
canthenbereusedinhigher-ordersequences.
Thegoalistocreateatoolsetthatprovides
asingle,consistentandmaintainablesystem
descriptionthatcapturesthesystem’slogical
functionality,itshierarchicalstructure,itsinternal
andexternalrelations,andultimatelyhowitrelates
toimplementationanddeployment.Inotherwords,
theaimistobuildatoolsetthatsupportsbothhuman
understandingandformalstringency.
Thefundamentalenablers
TheopensourcecommunityEclipse2
isagood
exampleofhowcollaborationacrossindustries
succeedstoday.Initially,theaimforEclipsewasto
createaplatformforsoftwaretooldevelopers.But
theplatformhassinceevolvedintoasophisticated
softwaresystemwithaspecializedsupport
environmentforcreatingabroadrangeofartifacts.
Eclipse
Abasicframeworkforcreatinginitialworkbenches,
Eclipsecanbetailored,providingnetworkarchitects
withtherightsupporttodescribeasystem.
EclipseModelingFramework(emf)
Thisframeworkincludesasetofsoftwaretoolsthat
enablelogicalmodelstructurestobecreatedand
managed.Inotherwords,containedelements,their
propertiesandtheirrelationshipscanbemodeled.
GraphicalModelingFramework(gmf)
Thisframeworkincludesfunctionalitythatrendersa
modelasacustomizablegraphic.
Papyrus
Astandard-basedmodelingtool,Papyrussupports
languageslikeuml andSysML,andisbasedona
setofEclipsecomponents,includinguml2,gmf,
emf,ocl andXtext.Designedfromthegroundup,
Papyrusisanattractiveimplementationsolutionfor
thetoolset,asitcanbeextended,specialized,and
adaptedtoappeartotheuserasadomain-specific
language(dsl),ormoreaccuratelyasadomain-
specificmodelinglanguage(dsml).Thiscapability
enablesarchitectstoworkusingmodelingconcepts
thatarenaturaltothecontextathand.
Genericmodelinglanguages—likeuml —
arepowerfulandflexible,astheycanbeapplied
toawiderangeofmodelingtasks.However,that
flexibilityisalsooneoftheirdrawbacks,asthe
responsibilitylieswiththeusertoperformthe
mentaltranslationfromcontextualtogeneric
modelingconcepts.Byinsteadusingadsl,this
responsibilitycanbeshiftedtothetoolset,allowing
architectstofocusonthejobathand:creatingthe
bestarchitecture.
Akeycomponentofanydesigntoolsetisthe
abilitytosharemodelinginformationacrossalarge,
andgeographicallydistributed,team.Onecandidate
opensourcetoolsetformanagingversions,parallel
developmentthreadsanddistributeddevelopment
isGit.WhilethistoolsetisincludedintheEricsson
solution,Gitwasprimarilydevelopedtosupport
codedevelopment,andassuchwasinitiallytext
focused.Fortunately,significantworkhasbeen
carriedoutoverthepastcoupleofyearstomakethe
compare-and-mergefunctionalitymodel-aware,
whichisavitalcomponentinthebiggerpicture.
Adomain-specifictoolset
TheEricssontoolsetforevolvingnetwork
architecture—networkarchitecturedomainspecific
language(nwa dsl)—isbasedonPapyrusand

25. #01, 2015 ✱ Ericsson technology review 25
Illustrative architecture ✱
«NWAComponent» S/I-CSCF
«NWAContext» S/I-CSCF
«NWAFunction» Function - S/I-CSCF
«NWAComponent» SIP routing
«NWAComponent» Registrar
«NWAComponent» Media handling
«NWAConnection» Dependency Media handling
«NWAConnection» Dependency Registrar
«NWAConnection» Dependency ISC
«NWAConnection» Dependency Cx
«NWAConnection» Dependency Mr
Diagram 3 - Next level - inside a CSCF
«NWAComponent» MRF
«NWAConnection» Dependency Mb
«NWAConnection» Dependency Mr
«NWAConnection» Dependency Mw
«NWAConnection» Dependency Cx
«NWAConnection» Dependency Iq
«NWAConnection» Dependency Mw
Figure4
The formal model

26. 26 Ericsson technology review ✱ #01, 2015
〉〉 graphicslibrary—customizedsvg shapesfor
visualizingdifferentnetworkfunctionsindiagrams;
〉〉 palettes—showingtheuserwhatelementsare
availableforbuildingnetworkarchitectures;and
〉〉 software—toimplementtheassociatedlogic,including
theadditionalui menusneededforthenwa dsl.
However,providingthelogicandrendering
informationisstillnotenough.Todescribethe
perfectsystem,domain-specificpropertiesthat
donotbreakthefundamentalassumptionsof
Papyrusanduml areneeded.Thisiswherethe
stereotypemechanismofuml comesintoplay.By
extendinguml Components(definedintheuml
standard)withstereotypedesignators,thecss-
basedgraphicsrenderingprocesspicksupthe
stereotypeanditsassociatedpropertiestoproduce
thegraphicalrepresentation.Theresultingdiagrams
thatarchitectsusetovalidatetheirideasfocuson
essentialinformationanduseagraphicalsyntaxthat
ismeaningful,ratherthanthekindofgenericsyntax
usedbystandardmodelslikeuml.
TheEricssontoolsetcouldhavebeendeveloped
fromscratch.However,bybuildingdirectlyonthe
semanticrichnessofuml,theresultingtoolset
benefitsfromyearsofdevelopmentconducted
byexpertsinthefieldsofmodelingandtool
implementation.Inaddition,integrationwithother
dslsbasedonuml2profiles—bothexistingand
futurereleases—becomeseasier.Inotherwords,the
Ericssontoolsetnotonlybenefitsfromdevelopments
alreadydeliveredbytheEclipsemodelingcommunity,
but,andperhapsmoresignificantly,willcontinueto
benefitasenhancementsbecomeavailable.
Theopensourceapproach:
howandwhy?
Largesoftwareorganizations,likeEricsson,have
usedmodel-basedengineeringasakeybusiness
differentiatorinmanydifferentcontexts.Today,
modelingisusedinawiderangeoftasks,including
softwaredesign,systemdesign,information
structure,networkarchitecture,andthemappingof
businessprocesses.However,thereareafewissues
limitingthewideradoptionofthisapproachby
industry.
INVITE()
INVITE()
INVITE()
200 OK()
200 OK()
200 OK()
200 OK()
ACK()
ACK()
ACK()
ACK()
INVITE()
A:IMS Client B:IMS Client:S/I-CSCF :MTAS
Figure5
Simple sequence
diagram
References
1)Docker,WhatisDocker?,availableat:
https://www.docker.com/whatisdocker/
2)Ericsson,2014,Presentation,uml ordsml?,
availableat:
https://www.eclipsecon.org/europe2014/sites/default/
files/slides/Ericsson_NWADSL_at_EclipseCon_
Europe2014_0.pdf
supportskeyaspectsofarchitecturedesign,such
asadvancedmodelvalidation,modelandtool
integrations,deploymentanalysisandvalidation,
architecturalexploration,variationpoints,and
productlinemanagement.Essentially,thetoolset
includesthefollowingcomponents:
〉〉 uml2 profile—tailoredtothenetworkarchitecture
(nwa)graphicalmodelinglanguage(originallydefined
independentlyoftoolimplementation);
〉〉 stylesheets(css files)—togovernhowcustomized
diagramsarerendered;

27. #01, 2015 ✱ Ericsson technology review 27
Thislackofadoptionbyindustryismainlytool
related.Forexample,model-basedengineering
hasnopropersupportfordsml developmentand
customization,andnocapabilitiestosupportkey
developmentareaslikemodel-basedcollaborative
development,testing,deploymentonmulticore,and
model/toolintegrations.Theseissues,togetherwith
thelackofevolutionofcommercialtools,leadtothe
conclusionthatthetraditionalapproach,basedon
proprietarytechnologies,hasfailed,andthatanew
solutionbasedonopensourceisneeded.
Inlightofthisfailure,Papyrus—anindustrial-
gradeopen-sourcemodelingtool—providesthe
necessarybasistoestablishanewfoundationfor
model-basedengineering;afoundationbased
oncollaborationamongusers,suppliers,andthe
researchcommunity.
Papyrus(andotherrelatedopensource
technologiessuchasegit,emfCompare,and
uml2)hasevolvedtoanewlevelofmaturity,
onethathasenableditsuseatindustriallevel.
Collaborationisthekeyfactortoensureits
continueddevelopmentandmorewidespread
adoption—notjustwithsuppliersandindependent
developersbutalsowithothercompanies.
Interestingly,theneedsandrequirementsof
manydifferentcompanies,withdifferenttechnology
domains,aresimilartothetelecomdomain—
underliningthefactthatlargesystemdevelopmentis
highlygeneric.Forexample,thearchitecturedesign
characteristicsforperson-to-personinteractionare
moreorlessthesameforatelecomsapplicationas
theyareinthecontrolofelectricitygridsorremote
patientmonitoring.
Futuredevelopmentpossibilities
Fundamentally,buildingthebestnetworkfirst
requiresthecapabilitytomodelmanydifferent
aspectsofnetworkarchitecture,andsecondly,the
abilitytocaptureandmaintainrelationshipsamong
networkelements.
Thecompellingaspectofbuildingcomprehensive
systemmodelsistheabilitytorapidlycreatea
functionalmodelofacustomersystem,withproposals
forevolutionandtransformationpaths.Assuch,
thebenefitsofmodernarchitecturemodelingnot
onlyapplytoa
giventechnology
domain,butare
afundamental
enablerof
collaborationwith
customersand
partners.
Toensure
thelong-term
evolutionofthe
opensourcemodelingsolutionandthedevelopment
ofavibrantsupportcommunity,Ericssonisactively
supportinganddevelopingindustrialcooperation
initiativesinthisarea.Ultimately,theabilitytoshare
ideasandsolutions,andcontributetotheopen
sourcecommunity,arethekeyfactorsforsuccessful
opensourcemodeling.
Conclusion
Themodel-basedengineeringstrategyillustrated
bythenwa dsl examplelaysthegroundworkto
fulfilltheneedsofnetworkarchitecturemodeling,
whichare:
〉〉 flexibilityingraphicalrepresentation—toachievethe
rightlevelofabstraction;
〉〉 integrationpotential—efficiencyacrossthe
developmentandintegrationchains;
〉〉 abasisinanopensourcestrategy—promotinga
communityapproachthatcannotonlyprovidebenefit
tothetelecomsindustry,butalsotoadjacentindustries
experiencingsimilararchitecturalchallenges;
〉〉 easeofuse—tolowerthethresholdforarchitecture-
levelusers;and
〉〉 efficientcollaboration—tosupporttheentire
organization.
Applyingamodel-basedengineeringapproachto
networkarchitecturedesignresultsinincreased
productivityandenhancestheabilityofallparties
tounderstandthetargetsystem.Themodel-based
approachensuresthatthelevelofconsistency,
performanceandadaptabilityneededbyEricsson
anditscustomersissafeguardedasweprogress
deeperintotheNetworkedSociety.
the needs and
requirements of many
different companies, with
different technology
domains, are similar to
the telecom domain

28. 28 Ericsson technology review ✱ #01, 2015
✱ Illustrative architecture
Ulf Olsson
◆ Hasabackgroundin
software architecture for
large-scale distributed
systems, ranging from
military command and
control to current and
futuretelecommunications.
He joined Ericsson in
1996, working mainly with
packet-based systems
like Packet pdc, gprs,
umts, cdma2000 and
ims. He then moved on
to systems architecture
in areas like service
exposure and analytics.
He is currently a senior
expert at Group Function
Technology, focusing on
overall system architecture
issues including how to
represent them formally
and informally. He holds
an m.sc. in engineering
physics from the kth Royal
Institute of Technology in
Stockholm, Sweden.
Toni Siljamäki
◆ Hasabackgroundin
modeling and software
development for
embedded systems in the
Swedish defense industry.
He joined Ericsson in 1997
to work on bridging the gap
between hardware and
software design disciplines,
and held responsibility for
Executable uml modeling
support and model
compiler development —
transforming uml models
into executable code in
Erlang, Java, Plex-C and C
for different platforms.
Since 2013, he has
focused on basic core
capability and usability
improvements of Papyrus,
with a special focus on
dsml development and
customization. He has also
designed and developed
the nwa dsl for Papyrus
described in this article.
Francis Bordeleau
◆ Isproductmanagerinthe
eittesoftware design group
at Ericsson. His primary
focus is model-based
engineering and modeling
tools. In this role, he is
responsible for defining
product specifications
and roadmaps, developing
business cases, managing
budgets, running open
source initiatives, and
collaborating with other
companies, researchers,
and academia. Before
joining Ericsson in 2013,
he was founder and ceo
of Zeligsoft — a provider
of domain-specific model-
based engineering. He
has held the position of
Assistant Professor at
the School of Computer
Science of Carleton
University, Ottawa,
Canada. He holds a b.Sc.
in mathematics from the
Université de Montréal
(1989), a Bachelor of
computer science from the
University of Quebec (1991),
and a Master in computer
science (1993) and Ph.D.
in electrical engineering
(1999) both from Carleton
University.
theauthors

29. xxxx ✱
#01, 2015 ✱ Ericsson technology review 2929
When it comes to technology, relentless and
continuous development remains a constant
expectation. Within this context, certain significant
shifts and opportunities — or technology trends
— have a tendency to stick out.
Tech
trends:
5

30. Ericsson technology review ✱ #01, 2015
networking
asaplatform
F r o m s i n g l e - s e r v i c e to multi-application platform,
the communication network becomes a massively distributed
compute, storage, and networking infrastructure.
Just how much impact mobile communication, the network
infrastructure that carries it, and the applications that make it
interesting and useful have had on the world is not news. Every
industry on the planet is undergoing a transformation, adopting
digital and virtual processes, products, and ways of working — even
the mobile communication industry itself. And each individual and
organization is adapting to make the most of it. Virtualization and
programmability are at the core of this transformation. The network
resources that make it all possible are becoming virtual, more flexible,
and more usable, to form a versatile and global platform.
30
As d e p e n d e n c y o n networks rises, focus on security and
privacy increases. As networks transform from being closed, protected
environments into open, programmable, and distributed platforms, the
significance of security and privacy is gearing up a notch. The technology
challenge lies in utilizing the openness and global reach of the network
platform, while protecting assets and user privacy, so that society as a
whole can reap the benefits of new network capabilities without being
subject to attack or breaches of security.
HerearethefivetrendsthatourCTObelieveseveryoneinict shouldbe
keepinganeyeon.Theyrepresenttheprimarydrivingforcesbehindnew
businessopportunities.Insomecases,theywillcausediscontinuities,
andelsewheretheywillpresentchallenges.Buttogether,theywillsetthe
directionfortechnologydevelopment.
tighter
security
andprivacy

31. #01, 2015 ✱ Ericsson technology review 31
analytics
everywhere
I n c r e a s e d c a pa b i l i t i e s in analytics and machine learning
will unlock new ways of doing business.
Modern networks carry massive amounts of data, and the growth trend
shows no signs of leveling off. This volume of data is a highly valuable
resource, as it provides insight into customers, improves traffic pattern
predictions, highlights potential business opportunities, and can help
identify the services that are being used and those that aren’t. The key to
delivering these benefits is real-time analysis of network metadata.
31#01, 2015 ✱ Ericsson technology review
theiotopportunity
C u s t o m i z e d n e t w o r k s l i c e s to support
upwards of 26 billion devices (beyond 2020) of all shapes and sizes to
suit all needs. In our most recent Mobility Report, Ericsson estimated
that the global number of connected devices is set to top 26 billion
by 2020. Estimates from other ICT players are similar. Some predict
slightly more, some predict slightly fewer, but whatever the exact
figure, that’s a lot of devices to provision and a lot of data to manage.
And so, networks need to gear up, becoming more flexible and
rapidly scalable to cope with widely varying use cases.
moredigitaland
evermoremobile
As i n d u s t r i e s s h i f t to provide virtual products and services
Two major transformations — digitalization and mobilization — are changing
the way people and society function, and the media industry is leading the
way. Media has undergone several transformation cycles, from broadcasting
and the sale of physical products (like CDs and DVDs) through actual stores,
to selling digital products (downloads, pay-per-view, and on-demand TV)
through user portals, to selling services (like streaming) on a subscription
basis. This transformation has taken place at the same time as the dual shift
in the consumption of content (from the single fixed screen to multiple mobile
devices) and the creation of content (from enterprise to everyone).
Read more about each trend on http://www.ericsson.com/thecompany/our_publications/ericsson_technology_review/archive/technology_trends_2015

32. 32 Ericsson technology review ✱ #01, 2015
✱ The agile network
〉〉 Carlos Bravo
Francesco Caruso
Christian Olrog
Malgorzata
Svensson
András Valkó
The business environment of operators and service providers is going
through a fundamental transformation. By 2020, more than half1 of
the envisioned 50 billion devices will already be connected. And
while the ever-expanding use of connectivity presents a major growth
opportunity, it also creates new and tougher demands on networks
— and particularly on the processes for managing users
and devices.
for software defined
and virtualized networks
support
systems
Gearing up

33. #01, 2015 ✱ Ericsson technology review 33
The agile network ✱
Parallel to the connectivity revolution,
the digital economy has triggered a
transformation in the way services are
produced and consumed. Enabled by the
global communication infrastructure, a new
market of digital services is emerging. In this
market, people and organizations can expose
their digital assets, which can be rapidly
combined with partner assets to create new,
more useful, and more interesting services.
c o m m u n i c at i o n networkshaveakey
responsibility:toprovidethe­platformthatenables
thedigitalmarkettocontinuetodevelop.This
­responsibilitypresentsoperatorsandserviceproviders
withauniqueopportunity.However,thisopportunity
isoffsetbythechallengesofpricepressureaswellas
theperceivedcommoditizationofnetworks.
So,tocapturethedigitalmarketopportunity,both
telecomnetworksandsupportsystems—oss/bss
—needtogearup.
Gearingup
Business agility is one way to respond to the trends
of digitalization and pressed profit margins. By
being able to apply technologies that increase
the level of flexibility in networks, operators and
service providers can gear up from delivering
network infrastructure to becoming providers of
innovation platforms.
Todothis,valuableassets(likenetwork
infrastructure,thesubscriberbase,useridentities,
securitycredentials,locationandmobility
information,serviceandproductcatalogs,charging
andbillingfunctions,connecteddeviceidentities,
andmanymorecapabilitiesthatcanbeusedto
createdigitalservices)
needtobeleveragedin
newways.
Inthedigital
economy,onlyafew
playerswillownall
theassetsthatare
neededtocreate
attractiveservices.
Typically,assetsfrom
differentplayerswillbe
combineddynamically
incollaborative
organizations.Operatorswillblendtheircapabilities
togetherwithpartnerassetstoexposenovel
services.Theresult:innovation,mashedservices,
andhighlysatisfiedusers.
Thekeytosuccessinthedigitalmarketisthe
abilitytoadapt,andtruebusinessagility(illustrated
inFigure 1)requiresflexibilityinallthree
dimensions:networks,services,andcustomers.
Networkagility
Cloud,sdn andnfv arekeyelementsofnetwork
agility:thecapabilitytoefficientlyplanandbuild
networks,adaptthemtochangingrequirements,and
providesuperiorservicequality.
Serviceagility
Thekeystoachievingserviceagilityare:theability
tocreatenewservicesrapidly,tolaunchanddeliver
superior-­qualityserviceswithease,andtobeableto
­monetizethem.
Customeragility
Thekeystoachievingcustomeragilityare:theability
tointeractwithconsumersinawaythatisflexible
Time-to-market:
how quickly the
changing needs of
modern consumers can
be detected, and how
quickly they can be
reacted to
Terms and abbreviations
api—applicationprogramminginterface|etsi—EuropeanTelecommunications StandardsInstitute|nf—networkfunction|
nfv—NetworkFunctionsVirtualization|nfvi—NetworkFunctionVirtualInfrastructure |oss/bss—operationssupportsys-
tems/business supportsystems|pnf—physicalnetworkfunction|sdn—software-definednetworking|se—serviceenable-
ment |soa—service-orientedarchitecture |ttm—timetomarket|vApp—virtualappliance|vDC—virtualdatacenter |
vim—VirtualInfrastructureManagement |vnf—VirtualNetworkFunction

34. 34 Ericsson technology review ✱ #01, 2015
✱ The agile network
OSS/BSSandSE
Network
function
Cloud system
infrastructure TransportEquipment
Experience
assurance
Enterprise
catalog
Customer
partner
interaction
Customer
partner
management
Order
management
NF domain
management
Non-
virtualized
application
Transport
Virtualized
application
Transport
domain
management
vApp
management
Cloud SI
management
Revenue
management
Resource
management
Service
inventory
Service
enablement
System
infra-
structure
M M
SDN-C SDN-C SDN-C
Figure2
oss/bss architecture
for sdn/nfv-enabled
networks
Figure1
Business agility
$
Customer/partner management
and interaction
MAKE IT
EASY
MAKE IT
BETTER
MAKE IT
ACTIONABLE
MAKE IT
ACCESSIBLE
MAKE IT
PAY
MAKE IT
HAPPEN
MAKE IT
REAL
MAKE IT
WORK
Experience-to-
resolution
Service-to-
cash
Lead-to-
service
Idea-to-
implementation
Data-to-experience
Customer agility
Service agility
Network agility
Network and cloud management
Plan-to-
provision

35. #01, 2015 ✱ Ericsson technology review 35
The agile network ✱
anddynamic,theabilitytoexposenewservices,and
themeanstoproactivelyresolveproblemsorreactto
issuesrapidly.
Networkagility
Bothsdnandnfvplaykeyrolesingearingup
tothelevelofnetworkagilityneededtoexplore
theopportunitiesandaddressthechallenges
presentedbytheNetworkedSocietyandthedigital
economy.
The concept of network virtualization
— providing physical network resources
as virtualized entities — has already been
successfully applied to telecom networks.
Examples of this type of network partitioning
include vpns and vlans. In 2012, a group of
service providers launched the nfv initiative.
Their aim was to apply best practices from the it
industry — as it virtualized data centers and server
rooms — to the telecom domain. In other words,
how can network elements be virtualized so that
the maximum benefit from commodity-computing
technologies can be achieved, while improving
service agility and service efficiency at the same
time? The short answer is nfv and sdn.
nfv
Fromatechnicalpointofview,nfv promotes
thedecouplingofnetworkfunctions(nfs)from
hardware.Byapplyingvirtualizationtechnologies,
thesoftwareofnetworkfunctionscanbebroken
apartfromhardwareappliances.Inturn,this
separationunleashesmassiveflexibilityintermsof
hownf canbedynamicallydeployed,elastically
resized,andofferedonanon-demandbasis.Some
ofthepotentialbenefitsofthisflexibilityarereduced
costandlowerpowerconsumption,butgainscan
alsobemadeintermsofincreasedspeedand
efficiencyinthedeploymentoftelecomnetworks.
sdn
sdn providestheabilitytoprogrammaticallydefine
andmanagenetworks,whichenablesthecomplexity
ofunderlyingimplementationtobeabstracted
fromtheapplicationsthatrunonthenetworkand
consumeresources.Fromatechnicalpointofview,
sdn enablesseparationofthedataplanefromthe
controlplane.
Serviceproviderstypicallyusesdn totake
aholisticviewoftheirnetworks,applyingsdn
conceptsacrossnetworklayersanddomains,which
inturnenablesend-to-endprogrammabilty.
sdn andnfv together
Originally,theaimofcombiningnfvandsdnwas
todecoupleservicesfromresources,butwhen
thesetwotechnologiescometogether,theyprovide
theadditionalbenefitofdetachinglifecycle
managementfromphysicalconstraints.Today,
itispossibletoprovisionansdn/nfvservice
instantaneouslywithouttheneedtodeploynew
physicalresources.Thisflexibilityisthefoundation
ofnetworkagility.
Serviceagility
AtEricsson,oss/bss aredesignedaccordingtoa
functionaldecompositionofnetworkarchitecture
domainsthatnativelyaccountforsdn andnfv.
Similartonetworkagility,sdn andnfv playkey
rolesingearingupthelevelofserviceagility.
Figure 2showstheoss/bss andservice
enablement(se)architectureforsdn/nfv-
enablednetworks.Thediagramhighlightsthe
mainfunctionalblocks:oss/bss andse,network
functions,equipment(representingthecollectionof
physicalresources),thecloudsysteminfrastructure,
andtransport.
Figure 2 oss/bss architectureforsdn/nfv-
enablednetworks.
Annf canbesupportedbynative(non-
virtualized,physicalnf)orbyvirtual(avirtualized
applicationoravirtualizednf)resources.Froma
managementpointofview,nf aregovernedacross
twoorthogonalplanes:
〉〉 thenetworkfunctiondomainmanagementplane
—illustratedasNFdomainmanagementinFigure 2;
and
〉〉 thesupportingresourcesmanagementplane
—illustratedasvAppmanagement,inFigure 2.
Thenf domain-managementplanesupports
operationalneedsofnfs,suchasfaultmanagement,
performancemanagementandspecific
Virtual resource
A virtual resource is an
abstraction of a physical
resource — compute,
storage, or network.
Virtual resources can be
shared among multiple
consumers in such a way
that they appear to be
dedicated.

36. 36 Ericsson technology review ✱ #01, 2015
✱ The agile network
Business
logic
creation
environment
OSS/BSS
Network
function
Cloud system
infrastructure
Transport ITAccess
Resource
spec
Read
resource
spec
Service
spec
Read
service
spec
Define
service
spec
........
.......
.......
Assurance
logic
spec
Charging
logic
spec
Add
assurance
logic
Customer
segment
spec
Add
customer
segment
Product
offering
Publish
product
offering
Service
enablement
M
Domain
management
Customer
management
MCloud SI
domain
management
Resource
inventory
Service
inventory
Service
catalog
Product
catalog
Add
charging
logic
........
.......
.......
Orchestration
creation environment
Orchestration
execution
OSS/BSS
Cloud system
infrastructure
Transport ITAccess
........
.......
.......
Handle
customer
order
Handle
customer
request
Handle
service
order
Activate
resources
Domain
management
Domain
management
Service
catalog
Product
catalog
Resource
order
Cloud SI
domain
management
Customer
interaction
Customer
order
Product
order
Service
order
Network
function
Service
enablement
M M M M M
Figure 4
Lead to service
Figure 3
Idea to implementation

37. #01, 2015 ✱ Ericsson technology review 37
The agile network ✱
configurationfornfs;whilevApp management
handlesresourcesrequiredbyanetworkfunction
throughoutitslifecycle.
Thecloud-system-infrastructurefunction
aggregatesandmanagesvirtualresourcesacross
differentinstancesandtechnologies,offeredby
cloudsysteminfrastructures(inetsi terminology
nfvi +vim).
Clouddeploymentsoftenspanseveraldifferent
physicalsitesjoinedthroughaconnectivityfabric,
whichmayhaveaseparatemanagementfunction.
Thisfabric,illustratedbytransportinFigure 2,
canbeorchestratedtogetherwiththeresource
infrastructureusingsdn,effectivelyimplementing
avdc (oravirtualresourceslice)thatprovidesa
networkservice.
Thefunctionsintheoss/bss andse planeare:
〉〉 experienceandassurance—offeringservice
assurance;
〉〉 customerandpartnerinteraction—enablingboth
partiestointeractwithsupportsystemsthrough
multiplecommunicationchannels;
〉〉 ordermanagement;
〉〉 revenuemanagement—providingthecapabilitiesto
chargeandinvoiceforanytypeofproductorservice
usage;
〉〉 resourcemanagement—providingaunifiedresource
inventoryforbothvirtualandphysicalresources;
〉〉 serviceinventory;
〉〉 customer/partnermanagement;
〉〉 enterprisecatalog—consistingofproducts,services
andresources;and
〉〉 serviceenablement—providingserviceexposure
capabilitiestopartnersforserviceinnovation.
Theoss/bss andse planeinsdn/nfv-enabled
networksprovidescapabilitiestointroducenew
virtualnfsorvAppsprogressively.Inotherwords,
newvirtualnfsorvAppscanbeinstantiatedin
adedicatedslicecalledtrial.Atthesametime,
aninstanceofthesamenf canbeexecutingin
anotherslice—calledproduction.Theredirection
ofusersfromtheoldtothenewnf/applicationcan
becarriedoutgradually,withminimumimpact,
andmanagedprogrammaticallyinawaythatis
transparenttousersoftheservice.
Rapidbusinessinnovation
Supportsystems—oss/bss —providethe
necessaryfunctionstoencapsulatesdn/nfv
servicesandcombinethemwithotherassetsinto
productofferings.Thesesupportsystemsalso
handleproductlifecyclemanagement,thecapability
tochargeforproducts,andtheprocessforexposing
productstousersandpartners.
However,oneofthemostsignificantchallenges
foroperatorsandserviceproviderstodayistimeto
market(ttm).Onewaytoshortenthetimefrom
concepttodeliveryistohaveagoodunderstanding
ofbusinessprocesses,sothatthelevelofautomation
inprocessescanberaised.Byhavingwell-
documentedbusinessprocesses,preconfigured
solutionsandsuitescanbedelivered,whichinturn
enablesadditionalbusinessprocessinnovationand
increasedspeedwhenintroducingnewofferings,
allwhilemaintainingflexibilityandtheabilityto
integrate.
Assdn andnfv facilitatenewservices,these
technologieshavegreatestimpactonthebusiness
processesthatliebetweentheformationofanidea
anditsimplementation—suchasplanning,design
anddeployment.
Figure 3illustratessomeoftheactivitiesincluded
intheideas-to-implementationprocess.Itshows
apossiblescenarioforcreatingaproductoffering
fromtheservicesandresourcesmanagedbyseveral
functionaldomains.
Withinoss/bss,thekeylogicalfunctionofthe
idea-to-implementationprocessisthebusiness
logiccreationenvironment,whichisillustratedin
Figure 3.Resourceandservicespecificationsaswell
asproductofferingsarecreatedinthisenvironment,
whichallresultinaproductcatalogentry.
Theidea-to-implementationprocesscanbe
brokendownintoanumberofspecification
phases:networkfunction,resource,andservice
specification.
Networkfunctionspecification
Domainmanagementusestheinformation
providedinthenfspecificationtobuildthe
resourcesneededtoconstructthedesiredservices.
Virtualdata
centers(vDCs),
slicesandnetwork
services
A vdc is an instance of
a data center operated
on a per-tenant basis,
with flexible network
topology and basic
services — compute,
network, and storage —
as well as more complex
ones such as firewalling
and load balancing. A
vdc may span multiple
physical data centers
or be constrained
to a subset of the
infrastructure within a
single dc.
A virtual resource slice,
referred to as a slice, is
an isolated view of the
virtual resources — a
vdc in other words.
A network service (ns)
is composed of vnfs,
pnfs, virtual links
and vnf forwarding
graphs that support the
communication service.

38. 38 Ericsson technology review ✱ #01, 2015
✱ The agile network
Insomecases,thisisaready-to-usespecification
providedbythenfvendor.
Resourcespecifications
Thevirtualinfrastructureresourcesneededby
thenfsthatthecloudsysteminfrastructurewill
exposeneedtobespecified.Theseresourcesare
describedusingvdc andvApp templates,andmay
beprovidedbythevendor.
Servicespecification
Describes how transport service connectivity
could also be exposed and bundled together with
the target services defined by the market’s needs
into product offerings. These product offerings
may be targeted to any segment, such as media
providers or health care providers.Theservice
specificationincludescharacteristicsthatdefine
specificsoftheserviceinrelationtorequirements
ofthetargetsegment.
Thecatalog-drivenapproachfacilitates
onboardingofnewservices,throughsimple
modelingbasedonprincipleslikemodularityfor
definingservicesandreusabilitytoconstructricher
andaggregatedservicesandproductofferings.Itis
oneofthemainpillarsoftheideas-to-implementation
process,complementedbyeaseofintegration
throughstandardinterfacesandpre-integrationand
automationoftheend-to-endprocesses.
Instantlyavailableservices
Virtualizationofnetworkfunctionsandthe
decouplingofsoftwarefromhardwareenablefull
automationofthelead-to-serviceprocess(shownin
Figure 4)acrossfunctionaldomains.Automating
thisprocessincludesinstantiationoftheentire
softwarestackofnfsthatareencapsulatedin
aservice,reducingtimefromordertoservice
activation,andimprovingresourceutilization—as
resourcesbecomeallocatedshortlybeforeuse.
Service-orientedarchitecture(soa)and
innovativemicro-servicesprovideprogrammable
interfacesdesignedaccordingtowell-established
industrystandardsandmakemajorcontributions
toorchestrationandautomation.Theyaresomeof
thekeyarchitectureprinciples,whichtogetherwith
acommoninformationmodelexposeservicesusing
apis,enablingeaseofintegration—asdescribed
inapreviousEricssonReviewarticle2
.Thesekey
principlesallowtheinstantiationofnfsandthe
resourcesneeded.Theyfacilitatethecreationof
productofferingsfromservicesandresources
definedindifferentdomains—oss/bss,transport,
cloudsysteminfrastructure,andit.
Customeragility
Similar to network and service agility, sdn and
nfv play key roles in gearing up the level of
customer agility.
Inthedigitaleconomy,theroleofpartnerships
andecosystemsismoresignificantthantraditional
economies.Digitalizedbusinessescollaborate
more,andcombinetheirassetstogetherwith
partnerassetstoprovidecustomerswiththebest
services.Inthisenvironment,newwaysthatenable
mashedofferings,serviceexposure,andblended
servicesareneeded.
Serviceenablement,asshowninFigure 2,
includesthefunctionsneededtoenableoperators
andserviceproviderstomonetizetheirassetsand
connecttoothers.
Serviceexposure,oneofthecorefunctionswithin
se,providesaccesstonetworkcapabilitiesexposed
bytheservicedevelopmentenvironmentthrough
programmableinterfaces.Exposureenables
developers—eitherattheoperator,apartnerora
3pp —todesignandcomposeinnovativeservices.
Supportsystems—oss/bss —providethe
capabilitiestomanagepartnersanddevelopers,to
handleallcommunicationchannels,andtoorganize
theadministrationofproductsandservices.
Technologieslikesdn andOpenStackprovide
developerswithprogrammableinterfaces,which
canbeusedtogetherwithoss/bss capabilitiesso
thatnewservicescanbedeployedandexecutedin
isolatedvirtualenvironments.
Inadditiontoexposingnetworkprogrammability
throughOpenStackandOpenDaylightapis,
developershaveaccesstootherservicesand
capabilitieslikeuseridentification,chargingand
networkpolicies,andconfigurationinformationto
programnfs.

39. #01, 2015 ✱ Ericsson technology review 39
The agile network ✱
Instance 4
Instance 3
Instance 2
OSS/BSS
Network functions
Health care
provider
Media
provider
Media
provider
Any industry
verticle
RAN
Instance 1
EPC-1 HSS-1
EPC-4 HSS-4
EPC-2 HSS-2IMS-2
EPC-3 HSS-3IMS-3
Figure5
Providing new
services with NFV

40. 40 Ericsson technology review ✱ #01, 2015
✱ The agile network
M M
OSS/BSS
SDN app
SDN app
specific
API
Root SDN
controller
Child SDN
controller
Forwarding
element
Router
OSPF
(for example)
BGP
(for example)
Data plane
SDN controller
management i/f
Transport
management i/f
Transport
management
i/f
Settlement
Element
management i/f
Peer
routing
domain
Peer
OSS/BSS
Operator A Operator B
Figure6
Software-defined
networking

41. #01, 2015 ✱ Ericsson technology review 41
The agile network ✱
Newbusinessopportunities
Thevirtualizationofnfsenablesoperatorsand
serviceproviderstodevelopnewservicesfor
traditionalsegments,aswellasprovidingthe
possibilitytoenternewmarkets.Forexample,
virtualizationenablesbundlesthatinclude
connectivityservicestobemashedwithvalue-add
servicesandexposedinaone-stop-shopfashion,
whichcanbecreatedandofferedtovarious
industryverticals.
Traditionally,aconnectivityservicesoffering
forindustryverticalstendsprovidenetwork
connectivityoptimizedforthespecificvertical.Ina
virtualizedenvironment,optimizationissimplified,
asnfscanbeinstantiatedforaparticularvertical,as
illustratedinFigure 5.
Thisillustrationshowshownfsandsupport
systemsinteract.nfsenabletheconnectivityto
connecteverythinginthenetworktogether—such
asmobilephonesandotherhandhelddevices,as
wellascars,andhealthcareandtransportation
equipment.Andthesupportsystems—oss/bss —
managethenfsandtranslatetheircapabilitiesinto
tangibleservicesthatcanbeofferedtoanyindustry
verticalthroughoperatorandserviceprovider
capabilities.
Operationalsimplicityandefficiency
Software-definednetworkingusuallyreferstothe
unbundlingorseparationofthecontrolplaneand
theforwardingplaneofnetworkelements.Itcanbe
solvedinmanyways,andOpenFlowisacommonly
usedprotocol.Traditionally,management
functionshavetypicallyinteractedwithinterfaces
exposedbythecontrolplanebutwithsdn,the
separatedforwardingplanebecomesamanaged
entityinitself.
Theseparationsdn providesresultsinfewer
controlplanes;thisinturnmakesiteasiertoalign
thedifferenttypesandversionsofcontrolplanes
andraisesthebarfortheleastcommondenominator
offunctionality.Takentotheextreme,thisconcept
resultsinasinglesdn controllerbeingsufficient,
andsoprovidesthebenefitsassociatedwithreduced
networkcomplexity.
While sdn is not a prerequisite for efficient
reconfiguration of
network resources,
it does provide a
solid foundation for
network agility. For
example, separation
has already led to
improvements and
new forwarding
service paradigms
like service
chaining3,4
.
Operational efficiency — not just for the single
service but the entire delivery operation — is
greatly enhanced by implementing an sdn fabric
that supports dynamic, automated and model-
driven reconfiguration. Furthermore, when
applications are added to the sdn controller
dynamically, the possibility to perform dynamic
protocol analytics increases, which in turn eases
troubleshooting.
Inannfv context,bothsdn controllersand
forwardingelementscanbedeployedasVirtual
NetworkFunctions(vnfs).Typically,hypervisors
alreadyincludeasoftware-definedforwarding
functionthatissdn capable,whichcanworkin
conjunctionwithphysicalforwardingelements.
Innovationinsdn networks
Oneoftheprimaryreasonstoshifttosdnisthe
potentialincreaseinflexibilityandagility.However,
itdoesnotnecessarilyfollowthattheintroduction
ofagiventechnologyautomaticallyleadsto
improvedagilityandmorestreamlinedoperations.
Typically,theadoptionofanewtechnicalmodel
followsahypecurve—adoptiontakesplaceonce
businessvaluehasbeenidentified,andproper
abstractionsareinplacetosimplifytheapplication
ofthetechnology.
InapreviousEricssonReviewarticle,theconcept
ofServiceProvidersdn4
wascoined.Thisconcept
takesaholisticviewofsdn,extendingitbeyond
thedatacentertoincludeabstractionsthatenable
servicestobebuiltthatleverageallthefunctionsof
theentirenetwork.
to capture the
digital market
opportunity, both
telecom networks and
support systems — OSS/
BSS — need to gear up

42. 42 Ericsson technology review ✱ #01, 2015
✱ The agile network
Shiftingtosdn/nfv
Bynature,sdn andnfv aredisruptivetechnologies,
andassuch,tendtofosterrapidinnovation.They
bringaboutchangesthatfundamentallyalterthe
traditionalwaynetworkshavebeenmanagedand
developed.
Asenablersofautomation,nfv andsdn make
fulluseofoneofthekeyarchitecturaloss/bss
principles—a­catalog-drivenapproachbased
onaunifiedmodelpromotingreuse,automation,
speedandcorrectness.
Theconceptsofthevirtualdatacenter(vdc)
andthevirtualresourcesliceenableservicestobe
deployedinparallel,andincontrolledisolation.
Thistypeofparalleldeploymentaddsflexibility
—becauseit,forexample,enablesoperatorsand
serviceproviderstorundifferentversionsofmulti-
tenantappliances,whichcanbedimensionedon
demand,andenablesservicestobepersonalized.
The ability to improve speed and correctness is
a key ingredient of innovation. By containing risk
and ensuring failures are detected early (failing
fast), operators and service providers can test
more concepts, and do this not just for services
and applications, but also for different market
segments.
The concept of time to market is changing.
Traditionally, ttm was about getting a version
of a service into the hands of paying customers
as quickly as possible. Today, ttm is about how
quickly the changing needs of modern consumers
can be detected, and how quickly they can be
reacted to.
Theoss andbss naturallyplayakeyrolein
enablingtheoperationofthisnewparadigm.
Automatingthedifferentflowsrequired,from
theideaofthenewservicetotheimplementation
andoperationofit,ensuresoperatorsandservice
providersareinfullcontroloftheirnetworkand
services,andareempoweredtoactoninsightsand
howtheyareused.
Theconceptsofsdn,nfv andthevirtual
datacenter,aswellasrapidadaptiontochanging
consumerneeds,formthepillarsuponwhich
network,serviceandcustomeragilityarebuilt.
References
1) Ericsson, June 2015, Mobility Report, available at:
http://www.ericsson.com/mobility-report
2) Ericsson, 2014, Ericsson Review, Architecture evolution for automation and network programmability,
available at:
http://www.ericsson.com/news/141128-er-architecture-evolution_244099435_c
3) etsi, 2014, Group Specification, Network Functions Virtualisation (NFV); Architectural Framework,
available at:
http://www.etsi.org/deliver/etsi_gs/NFV/001_099/002/01.02.01_60/gs_NFV002v010201p.pdf
4) Ericsson, 2014, Ericsson Review, Software-defined networking: the service provider perspective, available at:
http://www.ericsson.com/news/130221-software-defined-networking-the-service-provider-perspective_244129229_c

43. #01, 2015 ✱ Ericsson technology review 43
The agile network ✱
Christian Olrog
◆ Is an expert in
cloud service delivery
architecture and chief
architect at Business
Unit Support Solutions
at Ericsson. He joined
the department of New
and Special Business
Operations at Ericsson
in 1999 and has been
involved in research and
development in areas
ranging from wireless
lan standardization and
ip security to embedded
devices and enterprise
applications. He holds
an M.Sc. in physics from
kth Royal Institute of
Technology, Stockholm,
Sweden.
Carlos Bravo
◆ Isportfoliosalessupport
director and principal
architect in cloud and sdn
at Business Unit Support
Solutions at Ericsson.
He has over 15 years’
experience with operation
and maintenance systems
and processes and
systems integration. He
joined Ericsson in 2000
and has worked in all
stages of product life cycle
in Ericsson, from design
to delivery and execution.
He holds an M.Sc. in
telematics engineering
from the Higher Technical
School of Engineering
(etsi), Seville, Spain.
Francesco
Caruso
◆ Is an expert in cloud
architecture and
management at Group
Function Technology.
He joined Ericsson in
2012 from Telcordia
Technologies, where
he was director of the
Enterprise Integration
Group. He championed
the internal cloud program
to transition oss to the
cloud environment and to
extend oss into the cloud-
management domain. He
has more than 20 years’
expertise in the telecom
oss domain and holds an
M.Sc. in computer science
from the University of Pisa,
Italy.
Malgorzata
Svensson
◆ Isanexpertand oss/
bss chief architect at
Business Unit Support
Solutions at Ericsson.
She has over 15 years’
experience with operation
and business support
systems. She joined
Ericsson in 1996 and has
been involved in research
and development in areas
ranging from revenue
management, ims,
analytics, cloud and sdn.
András Valkó
◆ Isresponsiblefor
architecture and
technology within
Ericsson oss Portolio and
Solutions. He has nearly
20 years’ experience in the
telecom industry, mostly
within the area of network
management and oss,
with a focus on service
assurance, analytics,
performance management,
automation, and self-
organizing networks. He
holds a Ph.D. in computer
science and has a technical
research background.
Before his current
assignment, he was head
of Customer Experience
Management and Analytics,
and previously led the
Ericsson Research unit for
network management and
oss/bss.
Acknowledgements
The authors gratefully
acknowledge the
colleagues who have
contributed to
this article: Lars Angelin,
Henrik Basilier, Jan
Friman, Ignacio Más, and
John Quilty.
theauthors

44. 44 Ericsson technology review ✱ #01, 2015
✱ A step toward efficient virtualization
Service providers are looking to Network Functions Virtualization (nfv) as
a way to deliver and deploy Virtual Network Functions (vnf) services in a
flexible way, using virtualization and cloud computing techniques. As an IaaS
framework constructed as pluggable api components, OpenStack provides
a given level of automation and orchestration to deploy and provision nfv
services. But is it enough, and what improvements are needed?
〉〉 alan kavanagh
OpenStack as the API
framework for NFV:
the
benefitsand the extensions needed
Both OpenStack and nfv have developed con-
siderably over the past few years from an is/it
and a telecoms perspective.
While these two concepts relate to similar
areas — virtualization, rest-based apis, and
providing fast large-scale services indepen-
dent of underlying hardware — they address
these areas from different angles.
o n t h e o n e hand,etsi nfv aimstodefinean
architectureandasetofinterfacessothatphysical
networkfunctions,likerouters,firewalls,cdns
andtelcoapplications,canbetransformed:from
softwareapplicationsdesignedtorunonspecific
dedicatedhardwareintodecoupledapplications—
calledvnfs—deployedonvmsorcontainers,on
genericservers.
OpenStack,ontheotherhand,addressesservice

45. #01, 2015 ✱ Ericsson technology review 45
A step toward efficient virtualization ✱
provisioningandvirtualizationbyprovidingan
open-sourcesoftwareserviceframeworkthatis
api-drivenandpluggable,enablingpublicand
privatecloudstobequicklydeployedandmanaged
effectively.Ahigh-levelarchitectureofatelcocloud
servicebuiltusingOpenStackisshowninFigure 1.
Thetransformationtovnf servicesand
deploymentscenariosneedsanapi framework,
andOpenStackisasuitablecandidate.However,
toensurecarrier-gradeserviceandsupportfor
provisioningofnfv services,someextensionstothe
setofapisareneeded,andtheconceptasawhole
needstobeembraced.
Amodulararchitecture
In2010,Rackspaceandnasa jointlylaunched
thefirstreleaseofOpenStackdistribution
(Austin).Theiraimwastocreateanopen-source
cloudplatformthatcouldprovisioncomputing,
networkingandstorageservicesforprivateand
publicclouds.Inotherwords,alarge-scaleand
feature-richapi pluggableframeworkenabling
automatedservicedeploymentandprovisioning.
TheoriginalOpenStackarchitecturewas
modular,builtwithindependentcomponents
(services),calledthrougharest-basedapi
frontend.TheinitialRackspace/nasa release
includedjusttwoservices:Nova—formanaging
computeresourcepools;andSwift—theobject
storagesystem.Thearchitectureisstillmodular
today,butasFigure 2shows,ithasgrownwitheach
release,throughtheadditionofnewcomponents
providingextraservicesintheIaaSlayer.
AsanIaaSframeworkthatisflexibleandapi-
driven,OpenStackoffersvendorsandsolution
providersameanstointegratetheircompute,
networkandstorage-infrastructurepluginsbest
suitedtotheirenvironment.Assuch,OpenStack
enablesend-to-endservicedeployment,
provisioningandorchestration,reducing
implementationtimefromweekstohours.Thecore
servicesinOpenStacktodayinclude:
Horizon—aweb-basedserviceportalthat
providestenantsandadministratorswithauser
interfaceforprovisioningservicessuchasvmsand
objectstorage,andothercapabilitieslikeassigning
ip addresses,andconfiguringaccesscontrolfor
provisionedservices.
Nova—whichisresponsibleforcomputeservices,
suchasscheduling,andon-demandinitiationof
vms,LinuxContainers(lxc),orDockercontainers,
aswellastheremovaloftheseservices.
Neutron—whichprovidesnetworkingasaservice
tootherOpenStackcomponents(suchasNova).It
doesthisbycreatingandattachingthevirtualswitch
porttothevnic ofthevm,assigningtheip address,
configuringnetworkoverlayfortenantisolation,
andprovidingnetworkconfigurationforbaremetal-
provisionedservers.
Swift—whichprovidesmulti-tenantobject
storagewithinherentreplicationandautomatic
scaling.Itmanageslargevolumesofunstructured
data,whichisaccessedthrougharestfulapi.
Cinder—whichprovidespersistentblock
storageforinstances,suchasavm,runningonthe
OpenStackplatform.Italsomanagesblockstorage
devicesandvolumesnapshots.
Keystone—whichprovidesauthenticationand
authorizationforOpenStackservices,trackingand
authenticationofusers,aswellasauthorization
Terms and abbreviations
amqp—Advanced Message Queuing Protocol | api—application programming interface | bios—basic input/output
system | cdn—content delivery network | cee—Cloud Execution Environment | cli—command-line interface |
cpu—central processing unit | hot—Heat Orchestration Template | https—Hypertext Transfer Protocol Secure |
iaas—infrastructure as a service | kvm—kernel-based virtual machine | libvirt—virtualization API | nfv—Network
Functions Virtualization | ovs—open virtual switch | rest—Representational State Transfer | taas—tap as a service
| txt—Trusted Execution Technology | vm—virtual machine | vnf—Virtual Network Functions | vnic—virtual
network interface card

46. 46 Ericsson technology review ✱ #01, 2015
✱ A step toward efficient virtualization
OSS/BSS systems
Cloud and service
manager
APIexposure
Analytics,policy,securityinfrastructure
VNF VNF VNF
Compute Networking Storage Telemetry
VNF VNF
OpenStack
Virtualization layer (KVM/OVS, networking, storage)
Network
Heat
Horizon
Neutron
Cinder Nova
VM
Glance
Orchestrates
cloud
Provides UI
Provides
images
Stores
images
in
Provisions
Monitors
Provides
authentication for
Provides
volumes for
Backs up volumes in
Provides network
connectivity for
Swift
Ceilometer
Keystone
Figure 1
Telco cloud service
architecture on
OpenStack
Figure 2
OpenStack conceptual
architecture

47. #01, 2015 ✱ Ericsson technology review 47
A step toward efficient virtualization ✱
oftheservicesrequestedbyauser(beforethe
servicerequestisprocessed).Thisisacommon
serviceusedbyallOpenStackapi servers.
Glance—whichstoresandretrievesvm disk
imagesandcorrespondingmetadata.
Heat—whichprovidesorchestrationofservices
usingHeatOrchestrationTemplates(hots),which
describeagivencloudapplicationandhowitis
deployedusingOpenStack.
Ironic—whichprovisionsbaremetalmachines
usingapxe boot,forexample.Byimage
provisioningbaremetalmachinesinanautomated
andorchestratedway,Ironiccanprovidehigh
performingcomputeclusters,withoutincurring
theoverheadsandlicensefeesassociatedwith
hypervisors.Thisisasignificantadvantagefor
applicationsandservicesthatperformhighpacket
processing,andrequiredeterministicperformance
aswellaslowlatency.
Functionalblocks
ThecoreofeachOpenStackservice,whichis
commonlyreferredtoasthecontroller,manages
thegivenservice.ServiceslikeNovaandNeutron
arebuiltonapluggablearchitectureandusean
apiweb-basedservicesfrontendformanaging
thecontroller.Thefrontendisresponsiblefor
handlingauthenticationandauthorizationof
apicallsviaKeystone,aswellascommandand
controlfunctionslikerequestingordeletingavmor
establishingadmin/userrights.AsFigure 3shows,
anOpenStackservicecallsanotherOpenStack
servicethroughitsnorthboundapi.Initialservice
requestsaresentthroughaserviceportal,which
canbethedefaultdashboard(Horizon),orthrough
amoreenrichedcloudmanagerthatinterfaceswith
thenorthboundapioftheOpenStackcontrollers.
Anothermethodistoaccesseachindividual
OpenStackservicedirectlyviathecli,thoughthis
ismostcommonlyusedfortroubleshootingand
advancedadministratortasks.
Forexample,theNovacomputecontroller
comprisesasetofservicesincluding:
〉〉 NovaScheduler—whichdetermineswherethe
computeserviceshouldbeinstantiated;
〉〉 NovaConductor—whichactsasaproxyforrequests;
〉〉 NovaComputeAgent—whichrunsonthecompute
blade;and
〉〉 Novadatabase(db)—whichstoresmostbuildtimedata
(resourceavailability,consumptionandstate)forwhat
instancesarerunningandwhichcomputebladethey
arerunningon.
Thetasksthesecontrollerelementscarryoutto
completeaservicerequestarebestdescribed
throughthestepsintheprocesstodeployavm —a
commontaskcarriedoutbytenantsloggedontoa
(Horizon)serviceportal.
vm bootprocess
Theapi queryforvm deploymentisfirst
authenticatedbyKeystone.Ifsuccessful,therequest
ispassedontotheNovaScheduler,whichallocates
acomputebladeforthevm,andthenpublishes
therequest,viathemessagequeue,totheNova
ComputeAgent.
Themessagequeueisusedforcommunication
betweenallOpenStackdaemonsandusesamqp —
typicallyimplementedwithRabbitmq.
Dependingonthehypervisororcontainer
solutionbeingmanaged,theNovaComputedaemon
willcalltherelevantpluginandtherelevantapi to
instantiateavm,forexample,viatheappropriate
hypervisor.Ifthedeployedsolutionisakvm
hypervisor,theNovaComputeAgentcallslibvirtto
instantiateavm,andthenupdatestheNovadbwith
thestatusoftherequestedvm.
Next,theNovaComputeAgentcallsNeutronapi
toprovisionandconfigurethenetworkingforthe
computeservice.Thismayincludeattachingthevm
tothenetworkaswellasallocationofanIPaddress.
Afternetworkprovisioning,NovaComputeAgent
callsCinderapi toprovisionpersistentblockstorage
basedontenantpreferences.
Glanceapi isthencalled,andreturnstheurl
denotingwherethevm imagefileisstoredinthe
backendobjectstore,whichNovaComputeAgent
usestodownloadit.Oncetheimageisinstalledon
thecomputeblade,thevm willboot.
Thestepsinthisprocessindicatehowvnfscan
beorchestrated,andautomaticallyprovisioned
anddeployed,usingOpenStackservicesinavm

48. 48 Ericsson technology review ✱ #01, 2015
✱ A step toward efficient virtualization
environment.Provisioningofvnfsviabaremetal
wouldalsofollowasimilarprocess—whichis
supportedbyIronic.vnfsthatrequireallavailable
resourcesonagivencomputeblade,suchasram,
cpu cores,diskI/Oand/orfullnic bandwidth,
arebestsuitedtobeprovisionedonbaremetal—
withoutahypervisor.Inthiscase,theNovaCompute
usesabaremetalplugintocalltheIronicapi server
thatqueriestheIronicConductortofetchtheimage
files.OnceNeutronhasprovisionedandconfigured
therequirednetworking,thebaremetalnodeis
deployed,andpxe bootisinitiatedtoretrievethe
vnf applicationuntilthenodeisrebootedandup
andrunningwiththevnf application.
Forvnfsthatarecpu heavy,memoryintensive,
andhavehighdatabasetransactionfrequency,the
Ironicapi serviceisimportant.Thisisbecauseit
providesautomateddeploymentandprovisioning
ofthevnf oranyapplicationonbaremetalservers,
andremovestheneedforahypervisor,whichinturn
reducesoperatingcostsandcomplexity.
Pluggablearchitecture
ThemainadvantageofOpenStackisthepluggable
natureofitsframeworkarchitecture.Asvisualized
inFigure 3,theflexibilityofferedbysuchan
architectureallowsserviceproviderstochoosethe
bestbackendsolutions,whichcanbeconnected
throughtheappropriateplugin.Whichvendor
pluginismostappropriatedependsontheservices
thecloudproviderwantstooffer,theinfrastructure
beingdeployed,andtheavailablevendorsolutions.
TakingNeutronandEricssonasanexample,
anEricssonLayer-2/Layer-3 solutionwould
usetheEricssonNeutronplugin.Thepluggable
architectureoffersOpenStackNeutronaway
toextenditsfunctionalitywithmoreadvanced
networkingsolutions,suchasfirewall,vpn,load
balancingandportmirroring,implementedas
standaloneserviceplugins.Inthisway,networking
modulesinNeutroncanprovideadditionaland
muchneededfunctionalitythatcanbeselected
andincludedintheoverallsolutionbasedonthe
requirementsoftheserviceprovider.
TheNova-Dockerpluginhasbeenrecently
developedtosupportthedeploymentofDocker
containersviaNovaController.Whilesome
vnfstakeadvantageofcontainers,theyarenota
completereplacementsolutionforvmsorbaremetal
deployment,butprovideanotherdeploymentoption
thatissuitableforsomeapplications.Infact,asmore
lightweightcontainersolutions—likeUbuntu’slxd
—becomeavailable,thepluggablearchitectureof
OpenStackreallycomesintoplay.Deploymentand
provisioningofthegivencontainersolutioncanbe
achievedbysimplyaddingthespecificNovaplugin
andcallingtheOpenStackapi toprovisionthevnf
withaspecificdeploymentoption.
Thepluggablearchitectureisidealforvnfsthat
requirespecificnetworkingconfiguration,such
asvlan trunking,oradvancednetworkservices
likeLayer-3 routing,astheyrequiredynamic
routingprotocolstobeprovisionedinadditionto
multiplevirtualrouters.However,supportorfull
implementationforsuchadvancedservicesisnotyet
includedinOpenStack,illustratingsomeofthegaps
thatremaintobefulfilledbyNeutrontosupportall
nfv deploymentandconfigurationscenarios.
What’sneeded?
OpenStackprovidesanIaaSon-demandcloud
resourcedeploymentandconfigurationservice
thatenablesvnfstobedeployedquickly(within
amatterofminutes)ongenerichardwarethrough
automaticdeploymentandprovisioningofvnfsin
acloudenvironment.Thebenefitsfornfv vendors
andserviceprovidersinclude:
〉〉 fastertimetomarket—reducingthetypicalleadtime
fromweekstominutes;
〉〉 elasticscalingofvnf services—whichresultsin
maximumutilizationofhardwareresourcesand
reducescapexandopex;
〉〉 supportforvariouscomputeresourcesandflavors—
offeringseveraldeploymentoptionssuchasbaremetal,
containers,andhardwarevirtualization;
〉〉 automatedcontinuousdeploymentandrolling
upgrades;and
〉〉 pluggablebackends—allowingvendorsandservice
providerstoprovideinnovativesolutionsbasedon
deploymentandserviceneeds.
Asanopen-sourceproject,OpenStackislicensed
underApache2.0and,assuch,providesabasis