QualityofServiceinLTE
Contents
ExecutiveSummary................................1
Overview................................................2
NetworksCovered..................................2
HSPA<EInterworking......................3
CDMA<EInterworking.....................3
MVNOEnvironments............................4
TheFallofErlangandtheRiseofIP...........4
ProtocolStacks:LTEisallIP..................6
MechanicsofPer-HopDifferentiatedQueuing
.....................................................7
Keyfunctionsin3GPPPCCstandards..............7
3GPPPCCTheoryofOperation....................11
TFT...................................................12
PCCruleparameters..........................14
Whatisthe“End”inEnd-to-End?.................14
LTEQoSUseCases:FairshareTrafficManagement
..........................................................16
PCRFSignaling.....................................17
In-BandMarking(TEIDmodification)..........17
In-BandMarkingSGi(DSCPModification).....18
ComparisonofTechniques.......................18
AutomatedQoSControlforMobileNetwork
CongestionManagement.........................19
ConclusionsandRecommendations...............21
ExecutiveSummary
Aseachcommunicationsserviceprovider(CSP)transitions
variousnetworktypestoLTE,theefficienthandlingofsubscriber
QualityofService(QoS),bothinsideandacrossdifferent
networks,isapressingissue.
Inthissweeping,in-depthlookatvariousnetworktechnologies
andavailableapproachestoQoS-handlingwithinandacross
networks,Sandvinedrawsoutthekeyissuesandpresents
recommendationsforsoundNetworkPolicyControl:
?Affectednetworktypesandarchitectures
?Evolutionandconsequencesoftheall-IPnetwork
architecture
?Backgroundandexplanationofthe3GPPelementsused
inthedeliveryofservices,andtheirkeyfunctions
?Explanationofthe3GPPPCC(policyandcharging
control)theoryofoperation
?Issuesassociatedwiththeboundaryinterchangebetween
networktypesforQoS
?KeyquestionsanddecisionsCSPsfacewhendefiningand
managingend-to-endQoSinLTEandbetweennetworks
?Explanationofthethreepossiblemechanismsthatexist
forper-sectorprioritizationinnetworksthathave
deployedLTE
?Comparisonandprosandconsofeachofthepossible
QoS-handlingtechniquesforLTE
Finally,thepapershowshowtheinherentflexibilityofSandvine
technologyallowsourFairshareTrafficManagementtosupport
allthreeQoS-handlingmethodsforLTEnetworks,including
uniquesupportforthemosteffectiveandefficientapproach.
QualityofServiceinLTE
Page2
Overview
AlthoughthisdocumentfocusesonLTE(3GPPR9andlater),muchofthebackgroundformobile
networkQoScomesfromearlier3GPPrevisions.Inparticular,muchofthebaselineframeworkwas
definedin3GPPR7(shownbelowinFigure1),soitisusefultohighlightthedifferences.This
documentreferstoH-PLMNasthehomenetwork,theoperatortowhichthesubscriberpaysafee,and
theV-PLMNasthevisitednetwork,theonethesubscriberiscurrentlyattachedto.Thenormalcaseis
thattheH-PLMNandV-PLMNarethesame,andthesubscriberisnotroaming.
Figure1:Typicalinfrastructuralroaming,3GPPR7
NotcoveredareQoSissuesthatoccurinsidethehandset.Oldercircuit-switchedvoicehandsets
guaranteequalitydirectlyinthebasebandandreal-timeoperatingsystem.Newersmartphoneshave
movedtonon-real-timeoperatingsystems(BSD-basedforApple,Linux-basedforAndroid,Windows-
basedforMicrosoft),andthereisthestrongprobabilityof‘jitter’and‘lag’beingintroducedinsidethe
OSscheduleritself.
Inaddition,roamingbetweenLTEandHSPAnetworksispossible,asisroamingbetween3GPPand
3GPP2networks,andthishasaconsequenceonQoSandmappingbetweencapabilities.Therefore,the
boundaryinterchangebetweennetworksforQoSisthoroughlydiscussedinthispaper.
NetworksCovered
Theissuesandpointsdiscussedinthispaperareapplicabletothefollowingnetworktypesand
interactions:
QualityofServiceinLTE
Page3
HSPA<EInterworking
AmobileoperatorcurrentusingHSPAtechnologies,andmigratingtowardsLTE,willusuallysupport
softhand-off(e.g.,adual-modedevicewhichcanswitchmid-sessiondependingonavailable
coverage).ThistypeofnetworkisshowninFigure2.
Figure2:LTEandHSPAinterworking
CDMA<EInterworking
SomeoperatorscurrentlyuseCDMA(3GPP2)technologies,andaremigratingtoLTE.Aspartofthe
migrationtheymaysupportsofthand-off(e.g.,user-equipmentthatcanstartasessionononenetwork
andmovetoanothermid-session).Hardhand-offtechniquesarenotcoveredhere.Figure3showsa
networkdiagramforamixedCDMAandLTEoperator.
Figure3:LTEandCDMAinterworking,singleoperator
QualityofServiceinLTE
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MVNOEnvironments
AnothercasecoveredisthatofanMVNO(MobileVirtualNetworkOperator).Therearetwotypesof
MVNO:fullvirtual(simplyamarketingbrand,nonetworkatall),andapartialinfrastructuralMVNO,
owninganHLR/AAAandaGGSN.ThelatterisshownbyFigure4.AnMVNOwithapartialinfrastructure
hastheabilitytocreatedifferentiatedradioaccessbearersviatheirGGSN,andcaremustbetakento
preventanimbalanceinend-consumerexperienceonthesharedinfrastructure.
Figure4:MVNOenvironment
TheFallofErlangandtheRiseofIP
Sincethebeginningofthe20
th
century,voicenetworkshavebeenengineeredforcapacityaccordingto
theErlangmodel.Incomparisontodatanetworks,voicenetworkshavesomekeysimplificationsthat
allowedthemodelingtooccur:
?Voiceistreatedasconstantbitrate(i.e.,onevoicecircuitusesconstantnetworkbandwidth)
?Voiceistreatedasasymmetricpath(bothdirectionsfollowthesamelinks)
?Voiceistreatedasasinglepath(nomulti-pathnetworksareused)
?Voicesessionsstartatapredictablerateaccordingtohumanbehaviour
?Voice‘packets’arefixedsize
?Sessionsgofrommany-to-one(handsetstovoiceswitch)anddonotinteractwitheachother
Asaconsequence,telephonynetworkproviderswereabletobuildtheirnetworkcapacityaccordingto
simpleandfixeddesignrules(e.g.,99.99%ofcallswouldcompleteatthebusiesthour).Itisassumed
thequalityofacallisBoolean–ifitconnects,ithasperfectquality;ifthereisinsufficientcapacity,it
isblocked(connectionadmissioncontrol).
Early-generationmobilenetworksintroducedsomecomplexitytovoiceErlanginthatthehand-off
betweenlocationshadtobehandledastheusermoved,buttheoverallrulesandtechnologiesstayed
thesame-anend-to-endcircuitfromtheuserhandsettothemobile-switchingcenter(andfromthere
tothecallrecipient)startedatapredictable,lowrateandusedafixedcapacityinasymmetric
fashiononasinglepath.
QualityofServiceinLTE
Page5
Asdataneedsgrew,IPpacket-switchednetworksbecamethede-factostandard.Networkengineering
indatawasperformedbasedonpeakobservedloadandforward-predictionmodelssuchasHolt-
Wintersforecasting.Capacity-basedbillingmodelsemergedbetweencarriersbasedon95-percentile.
QoSswitchedfromdeterministictoprobabilistic.Circuit-basedQoSwasreplacedbyper-hop
behaviour.Withinaserviceprovider,QoSmanagementmaybeperformedusingDifferentiatedServices
CodePoint(DSCP)tomodifytheprobabilityonaper-hop-basis.QoSmanagementbetweenoperatorsis
rare.Operatorstypicallyprovisionmanagedservicessuchasvideoandvoiceusingtraditionalcircuit-
switchedmodels,non-convergednetworks,ornetworksconvergedatthephysicallayerbutpartitioned
usingtechniquessuchasMultiprotocolLabelSwitching(MPLS).Networksarenormallytreatedasnon-
oversubscribedexceptforthe‘last-mile’consumeraccess.
Applicationsrequiringqualitygoalstypicallybuildthemintotheapplication(usuallywithbuffering,or
withcomplexcodecssuchasSkype’sSILK,whichallowforpacketloss).Theoversubscriptioninthe
fixednetworksisnormallysufficientforQoS-sensitiveapplicationssuchasSkypeandNetflixto
functioninabest-effortenvironmentmostofthetime.
Figure5:MRTGutilisedcapacitychart,95%lineshown
Asmobiledataemerged,networkengineeringbasedonobservedtrendsbecameproblematic.Thehigh
rateofadoptionofnewdevicesandnewapplicationsmeantthatcapacitycouldnotbeaddedquickly
enough.Thedisparitybetween‘busy’and‘non-busy’mobilesectorsisnowhighintermsofvolume,
andthesectorsthatarebusyvaryduetomobility.
Sincedataapplicationsusevariablepacketsizes,theytendtointeractwitheachotherpoorlyasthe
linksapproach70-80%utilization.Inparticular,latencytendstogoupexponentiallyasthelink
utilisationgoesover75%.ApplicationswhichuseTCPandlargepacketstendtodominatethe
throughput,creatinglatencyissuesforsmallerpacketapplications.
Figure6:Ethernetutilizationvs.loss/latency
0
20
40
60
80
100
120
140
0%
20%
40%
60%
80%
100%
120%
10%20%30%40%50%60%70%80%90%100%
L
a
t
en
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(
m
s
)
Lo
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%
)
Utilization(%)
EthernetUtilisationvs.Loss/Latency
LossLatency
QualityofServiceinLTE
Page6
ProtocolStacks:LTEisallIP
OneofthedesigngoalsofLTEwastobeentirelyIP(includingcarryingvoiceoverIP).Asa
consequence,QoSmustbeunderstoodinboththecontextofthe‘inner-tunnel’,whichinteroperates
withthepacketcoreandradionetwork,andthe‘outer-tunnel’,whichusestraditionalIPtraffic
engineeringtechniques.Thevarioustunnelingandencapsulationprotocolsthatarerequiredareshown
inFigure7.
Figure7:LTEmajortransportencapsulations
ItiscommonpracticeforanoperatortouseMPLSorothertunnelingtechnique(seeFigure8),andin
practicaltermsitisimpossibletoconveytheQoSmarkingsfrominner-tunnelstoouter-tunnels.Abest
practiceistoengineerthenetworksuchthatthereisonlyonepointofcongestion(theeNodeB).This
maybedifficulttoachieveastheS1-Umaybesignificantlyover-subscribed.Asaconsequence,the
usualrequirementistouseouter-marks(DSCP,MPLS-EX)thataredriveninconjunctionwiththeinner
marks(TEID).IftheP-GWisthelabel-edgerouterinthedownstreamdirection,onecanuseafeature
suchasCisco’s“ipuser-datagram-toscopy”,whichcausestheinner-packetencapsulatedbyGTP-Uto
alsodrivetheouterDSCP.ThiscaninfluencethetransportnetworkonS5andS1-Utosomewhatmatch
thedecisionswhichwillbemadebytheeNodeB(whicharebasedonthetunnel-ID(TEID)andthePDP
contextparameters).The“active-chargingservice”featurecanbeusedtoachievetheinverse-taking
un-encapsulatedpacketsfromSGiinterfaceandusingtheirDSCPmarktomaptoaspecificPDP-
context.
Figure8:PracticalLTEdeployment
QualityofServiceinLTE
Page7
MechanicsofPer-HopDifferentiatedQueuing
InIP-basednetworks,differentiatedserviceisperformedonaper-hopbasis.Themostcommon
techniquesusedareDifferentiatedServices(DiffServ,RFC2474,RFC2475,RFC3260),whichusesthe
6-bitDSCPfieldintheIPheader,andMPLS,whichalsousestheDiffServarchitecture,butwith
differentmarkingtechniques(RFC3270).Inparticular,MPLSsupports3-bits(8-levels)intheEXPfield.
In3GPP,theQoSClassIndicator(QCI)mapsdirectlytoDSCP.ThebasicclassesdefinedbyDiffServare
‘default’,‘expeditedforwarding’,and‘assuredforwarding’.Ofthese,expeditedforwardingisusedfor
‘strict’priority(e.g.,videoandvoice),and‘assuredforwarding’isusedforbusinessdifferentiation
(e.g.,weighted-fairpriority).
Oneofthelong-standingcomplexitiesofDiffServhasalwaysbeenitsbehaviourintunnels,and3GPPis
nodifferent.Ina3GPPenvironment,theoutermarkingisonlyusedbybackhaulnetworks,andinner
marksareignored.DiffServmaybeusedtomanageQoSonexternalnetworksandbemappedinto
3GPPbearers.Examplesofinterchangebetweenthetwoareproprietarypervendor,butinclude
Cisco’s“ipuser-datagram-toscopy”feature,whichcopiestheDSCPfieldfromtheinnerIPpacketto
theouterGTPheader,andCisco’s“active-chargingservice”feature,whichmapsun-tunneledpacket
DSCPfieldsintospecificradiobearersbymappingthemtoaspecificPDPcontext.Notethat,despite
thenumberoflevelssupportedinsignaling,individualequipmenttypesvaryinthenumberofqueues
supported,andinthequeuingbehaviour(strictvs.fair).Asaconsequence,manydistinct‘marks’map
tothesamebehaviouranditisimportanttounderstandtheinternalqueuingsupportprovidedbyeach
pieceofnetworkequipmentalongeachpossiblepath.
Keyfunctionsin3GPPPCCstandards
Beforemovingonit’simportanttothoroughlyreviewthesixmainfunctionsofthe3GPPPCCstandards
thatmanageservicesandQoSinmodernnetworks.ThefollowingcorefunctionsareshowninFigure9:
?SPR(SubscriptionProfileRepository)
?OCS(OnlineChargingSystem):optional-maybedealtwithusingGy/CCR
?AF(ApplicationFunction):oneperoperator-providedservice
?PCRF(PolicyChargingRulesFunction)
?PCEF(PolicyChargingEnforcementFunction)
?TDF(TrafficDetectionFunction):maybemergedintoPCEF
Figure9:3GPPPCCblockdiagram
QualityofServiceinLTE
Page8
AF
TheAF,ifinvolved,mayprovidethefollowingapplicationsessionrelatedinformation(i.e.,basedon
SIP
1
andSDP
2
?SubscriberIdentifier-typicallytheMSISDN(MobileSubscriberIntegratedServicesDigitalNetwork-
Number)oftheuser,ifknownbytheAF
):
?IPaddressoftheUE
?MediaType,MediaFormat(e.g.,mediaformatsub-fieldofthemediaannouncementandallother
parameterinformation(a=lines)associatedwiththemediaformat)
?Bandwidth
?Sponsoreddataconnectivityinformation(e.g.,allowingtheflowtobezero-ratedtowardsthe
consumer,andthechargeinaggregatetobedealtwithinsomeotherfashion)
?Flowdescription(i.e.,sourceanddestinationIPaddress,portnumbersandtheprotocol)
?AFApplicationIdentifier
?AFCommunicationServiceIdentifier(e.g.,IMSCommunicationServiceIdentifier),UEprovidedvia
AF
?AFApplicationEventIdentifier
?AFRecordInformation
?Flowstatus(forgatingdecision)
?Priorityindicator,whichmaybeusedbythePCRFtoguaranteeserviceforanapplicationsessionof
ahigherrelativepriority
?Emergencyindicator
?Applicationserviceprovider(i.e.,thediameterrealmorbusinessname)
SPR
TheSPRmayprovidethefollowinginformationforasubscriber,connectingtoaspecificpacket
gateway:
?Subscriber''sallowedservices(i.e.,listofServiceIDs)
?Foreachallowedservice,apre-emptionpriority
?Informationonsubscriber''sallowedQoS,including:
?theSubscribedGuaranteedBandwidthQoS;
?alistofQoSclassidentifierstogetherwiththeMBRlimitand,forreal-timeQoSclass
identifiers,GBRlimit.
?Subscriber''schargingrelatedinformation
?Spendinglimitsprofilecontaininganindicationthatpolicydecisionsdependonpolicycounters
availableattheOCSthathasaspendinglimitassociatedwithitandoptionallythelistofrelevant
policycounters
?Subscribercategory
?Subscriber''susagemonitoringrelatedinformation
?Subscriber''sprofileconfiguration
?Sponsoreddataconnectivityprofiles
1
SessionInitiationProtocol,RFC3261
2
SessionDescriptionProtocol,RFC4566
QualityofServiceinLTE
Page9
?MultimediaPriorityService(MPS)Priority(userpriority)
?IMSSignalingPriority
PCRF
APCRFhastwokeyfunctionsinthe3GPPPCCstandards:provisioningchargingrulestothePCEF
(performedonsessioninitiation),andcreating/destroyingdedicatedbearerPDPcontexts(andthus
radiobearers)inresponsetoarequestfromanApplicationFunction(AF).Itisimportanttonotethat
theuseofaPCRFisoptional;itisnotarequiredelementofa3GPPnetwork.
Theoriginalframersofthe3GPPPCCspecificationsanticipatedthePCRFinstallingdynamicrules(5-
tuplebased)onaper-flowbasis.In3GPPR8thiswasdeprecatedinfavourofapplicationdetectionand
control(ADC)rules(givingmuchgreaterscale),andthiswasformalizedinR11intheMay20113GPP
TSGSAWG2meeting.
Figure10:PCRFsystemarchitecture
PCEF
ThePCEFisthemaincomponentofPCC,anditsuseisnon-optional.Anoperatorcan(andcommonly
does)havepre-provisionedPCCrulesinthePCEF(otherbasicrulesarealsoprovisionedinthe
HLR/HSS).ThePCEFtypicallygetssubscriptioninformationfromtheAAAorS6ainterfacetowardsthe
HSS&AAA.ThePCEFperformsthefollowingprimaryfunctions:
?Gateenforcement.ThePCEFallowsaservicedataflow,whichissubjecttopolicycontrol,topass
throughthePCEFifandonlyifthecorrespondinggateisopen.Thisprovidesameansofblocking
unknownorunenforcedtraffic(andmaybeusedtoblock,forexample,userswithnocredit).
?ChargingTriggerFunctionwherethroughDiameterCreditControlitfeedsinformationtoanOnline
ChargingSysteminordertotrackusage.
?ChargingDataFunctionthroughofflinechargingrecordsrequiredfortypicalpost-paidservicesand
chargingreconciliation.
?QoSenforcement:
?QoSclassidentifiercorrespondencewithIPsession-specificQoSattributes.ThePCEFconvertsa
QoSclassidentifiervaluetoIP-sessionspecificQoSattributevalues(typicallyDSCP)and
determinetheQoSclassidentifiervaluefromasetofIP-sessionspecificQoSattributevalues.
?PCCruleQoSenforcement.ThePCEFenforcestheauthorizedQoSofaservicedataflow
accordingtotheactivePCCrule(e.g.,toenforceuplinkDSCPmarking).
?IP-sessionbearerQoSenforcement.ThePCEFcontrolstheQoSthatisprovidedtoacombined
setofservicedataflows.Thepolicyenforcementfunctionensuresthattheresourceswhich
canbeusedbyanauthorizedsetofservicedataflowsarewithinthe"authorizedresources"
QualityofServiceinLTE
Page10
specifiedviatheGxinterfaceby"authorizedQoS".TheauthorizedQoSprovidesanupper
boundontheresourcesthatcanbereserved(GBR)orallocated(MBR)fortheIPsessionbearer.
TheauthorizedQoSinformationismappedbythePCEFtoIPCANspecificQoSattributes.
DuringIP-CANbearerQoSenforcement,ifpacketfiltersareprovidedtotheUE,thePCEFshall
providepacketfilterswiththesamecontentasthatintheservicedataflowtemplatefilters
receivedovertheGxinterface.
TDF
Introducedin3GPPrelease11,theTDFcomponentisstillintheprocessofbeingstandardizedandhas
notyetbeenwidelyadopted.Itsexistencedemonstratesindustryrecognitionoftheriseand
predominanceofover-the-topapplications,whichdonotuseSIPandatraditionalAF.TheTDFmaybe
deployedintwodifferentways:itmaysignalonaperflowbasisafterdetectiontowardsthePCRF,or
itmayacttoperformthegating/redirection/bandwidthlimitationwithoutinformingthePCRF.The
latterusecaseismorecommonasover-the-topapplicationsoftenoperateatmuchgreaterscalethan
thePCRFiscapableofhandling.
3GPPtechnicalspecifications23.203and29.212version12describetherelationshipbetweentheTDF,
PCRF,PCEF,variousDiameterinterfacesandotherrelatedelementssuchasanOCS.Thekeyaspect
thatdeterminescomplianceasa3GPPrelease11orhigherTDFissupportforthenewlyintroduced
DiameterSdreferencepointdescribedinTS29.212.DiameterSdisusedforcommunicationbetween
theTDFandPCRFusingapplicationdetectionandcontrol(ADC)rulesfullydetailedinTS29.212.
3
The
PCEFusesPCCrulesandtheDiameterGxreferencepointtocommunicatewiththePCRF(inplace
sincerelease7andalsodescribedinTS29.212).Decisionsaboutwhichapplicationstodetectcanbe
installedlocallytoaTDFand/ortowhatthespecificationsrefertoasa“PCEFenhancedwithADC”;
thatis,aPCEFwithanembeddedTDF,whichhasembeddedADCrules.
4
TheTDFmayalsoprovideusagemonitoringtowardsthePCRF(sothatthePCRFcanprovidean
additionalformofmeteringwhenanOCSisnotpresentorcapable).3GPPrelease12introduced
chargingsupporttotheTDF,effectivelyduplicatingchargingfunctionsalsodescribedforthePCEF
element.BoththeTDFandPCEFelementsmustinterpretmonitoringkeysfromthePCRFandcharging
keysfromtheOCS.
3GPPrelease12introduced
chargingsupporttotheTDF,effectivelyduplicatingchargingfunctionsalsodescribedforthePCEF
element.ForthosecaseswhereservicedataflowdescriptioncannotbeprovidedbytheTDFtothe
PCRF,theTDFperformsgating,redirection,bandwidthlimitationandchargingfordetected
applications.ForthosecaseswhereservicedataflowdescriptionisprovidedbytheTDFtothePCRF,
actionsresultingfromapplicationdetectionmaybeperformedbythePCEFaspartofthechargingand
policyenforcementperservicedataflowandbytheBearerBindingandEventReportingFunction
(BBERF)forbearerbinding,oractionsmaybeperformedbythePCEF/TDFusingApplicationDetection
andControl(ADC)rules.
5
Indeed,thechargingsectionsofTS23.203oftendescribethePCEFandTDF
elementsasoneentity;forexample,thecreditmanagementsectionofTS23.203isaddressedatthe
“PCEF/TDF”elementhavingorreceiving“PCC/ADC”rules.
6
3
3GPPTS29.212V12.2.0(2013-09),section4b
AnnexQofTS23.203providesthe
followingviewofthelogicalrelationshipbetweentheseelementsandtheirinterfaceswhenonline
chargingandanOCSarealsoinplay:
http://www.3gpp.org/ftp/Specs/html-info/29212.htm
4
3GPPTS23.203V12.2.0(2013-09),section4.5http://www.3gpp.org/ftp/Specs/html-info/23203.htm
5
Ibid.
6
Ibid,section6.1.3.
QualityofServiceinLTE
Page11
PCEF/
TDF
PCRF
OCS
Gx,Sd
Gy,Gyn
Sy
Figure11:UsageMonitoringviaOnlineChargingSystem(3GPPTS23.203v.12.2.0,AnnexQ)
ItisanticipatedthattheTDFwillperformothertriggers(e.g.,locationchanges,congestiondetection)
sothatthePCRFcanbecomeawareofthenetwork.Asofrelease12,thestandardsremainvague
regardinghowtopology/locationinformationwillbeprovidedfromthePCRFtotheTDF.Somevendors
offerlocationawarenessusingproprietaryfeatures.Theoretically,thestandardsprovideanoptional
mechanismforeverylocationchangetobepropagatedfromtheRANallthewaytothePCRF.
However,forpracticalreasonsthishasnotbeenimplemented,andthereforetheTDFaspurely
describedinthelateststandardswillfaceasimilarproblem.
7
OCS
TheOCSisoutofthescopeofPCC,butdoeshavearecent(andnotwidelyadopted)interfacetowards
thePCRFforpurposesofcoordinatingpolicywithcredit.Acommonapproachistoperformthis
functionviathePCEFdirectly(asittoocommunicateswiththeOCSviaDiameterGy).TheOCS,if
involved,mayprovidepolicycountersstatusforeachrelevantpolicycountertowardsthePCRFover
thenewly–emergingSyinterface.Inaddition,thePCEFhasaconnectionviaGytowardstheOCS,and
canmakeitsownevaluationofrulesbasedoncreditresponses.
3GPPPCCTheoryofOperation
Figure12showstheoverallPCCsystemanditsinterconnectionstonon-PCCcomponents.
Figure12:3GPPblockdiagram,expanded,withcorePCCcomponentsshaded
7
ForacompleteoverviewofSandvine’sapproachthe3GPPrelease12andTDFstandards,seeTechnologyShowcase–TrafficDetection
Function.
QualityofServiceinLTE
Page12
Thegeneralsignalingflowthroughthe3GPPPCCarchitectureisinitiatedbyeithertheuser(session
initiation)orviatheAF/TDF.Thefollowingfivemajorsignalingflowsareimportanttodescribe:
1.Subscriberinitiatesbearer(createsPDPcontext):Whenthesubscriberregisterstheirdevicetothe
network,afterauthenticationbytheS-GWandtheHSS,adefaultbeareriscreatedontheP-GW.
ThePCEFinitiatesamessagewithGxtoloadtherule-setfortheuser(whichisultimatelystoredin
theSPR).
2.Application-functioninitiatedchange:Whenactivated,theAFsignalsthePCRFviaRxtoindicatea
newserviceflow(matchedusingIPheaderbits),selectingtheQoSandchargingparameters.The
PCRFprovisionsthisruleintothePCEFwiththeappropriateTFT&QCI,whichcommencestheQoS
andchargingasspecifiedbytheAF.
3.TDF-initiatedchange:ConceptuallythisisidenticaltotheApplication-functioninitiatedchange,
exceptthatitisbasedondetectinganapplication,ratherthantheuserinitiatingtheapplication.
4.Network-initiatedchange(RATchange,lossofbearer,QoSchange,etc):Basedonaruleonthe
PCEF,atriggercanbesenttowardsthePCRF(usingdiameterGx).Examplesincludequota
exceeded,startuseofanapplication,entrancetoaspecificlocation,etc.
5.PCRF-initiatedchange.ThePCRFisfreetoruninternallogiconconditionsitisawareof,and
changetheprovisioningofrulesonthePCEFusingaGxRAR.
TFT
In3GPP,aTFT(TrafficFlowTemplate)isaclassifierthatmatchesonfieldsontheinner-IPofaGTP-U
tunnel.Thisinturncausesdifferentiatedradio-bearerperformance.Itcanmatchthefollowingfields:
?Sourceaddress(withsubnetmask)
?IPprotocolnumber(TCP,UDP)
?Destinationportrange
?Sourceportrange
?IPSecSecurityParameterIndex(SPI)
?TypeofService(TOS)(IPv4)
?Flow-Label(IPv6only)
Whetherusingthestatic-TFTmodelorthedynamicGx-signaledTFTmodel,thesamesequenceoccurs:
adedicatedbearer(secondaryPDPcontext)iscreated,andtrafficisforcedtomatchit.Operatorscan
createPDPcontextsdynamicallyusingGx,inwhichtrafficmatchingtheTFTfiltersintothecontext
basedonrulesinthePCEF,orhavingdynamicPDPcreationdonebythepacketgatewayitselfbasedon
trafficmatchingwithpre-provisionedvalues.ThiscanbeusefulifanupstreamdeviceonSGiwillmark
packetsmatchingcertainconditionswithDSCP.
Figure13:TFTmappingtoPDPcontexton3G(dedicatedbeareranalogoustosecondary)
QualityofServiceinLTE
Page13
TheLTEversionofthestandardsallowsuptonineTFTstobeusedperbearer.Inpriorrevisions,there
isonlyoneTFTallowed,whichisimportanttonoteifQoShandoffbetweenHSPAandLTE,orLTEand
CDMAisneeded.
TheTFTselectswhichPDPcontextisused,andtheQCIlabelisashort-handfortheQoSparameters
withinthecontext.NotetheQCIisashort-handlabelonly.ThestandardizedQCIcharacteristicsare
givenasroughguidelinesinTable6.1.7of3GPPTS23.203(v11.3.0),reproducedhere:
Table1:Table6.1.7from3GPPTS23.203V11.3.0
QCIResourceTypePriority
PacketDelay
Budget
PacketError
LossRate
ExampleService
1(Note3)
GBR
(guaranteed
bitrate)
2100ms10
-2
Conversational
Voice
2(Note3)4150ms10
-3
Conversational
Video(live)
3(Note3)350ms10
-3
Realtimegaming
4(Note3)5300ms10
-6
Non-
Conversational
Video(buffered)
5(Note3)
Non-GBR
1100ms10
-6
IMSSignaling
6(Note4)6300ms10
-6
Video(Buffered
streaming)
TCP
7(Note3)7100ms10
-3
Voice,Video
(Live),Interactive
Gaming
8(Note5)8
300ms10
-6
Video(buffered
streaming),TCP9(Note6)9
NOTE1:Adelayof20msforthedelaybetweenaPCEFandaradiobasestationshouldbesubtractedfromagiven
PDBtoderivethepacketdelaybudgetthatappliestotheradiointerface.Thisdelayistheaveragebetweenthe
casewherethePCEFislocated"close"totheradiobasestation(roughly10ms)andthecasewherethePCEFis
located"far"fromtheradiobasestation,e.g.incaseofroamingwithhomeroutedtraffic(theone-waypacket
delaybetweenEuropeandtheUSwestcoastisroughly50ms).Theaveragetakesintoaccountthatroamingisa
lesstypicalscenario.Itisexpectedthatsubtractingthisaveragedelayof20msfromagivenPDBwillleadto
desiredend-to-endperformanceinmosttypicalcases.Also,notethatthePDBdefinesanupperbound.Actual
packetdelays-inparticularforGBRtraffic-shouldtypicallybelowerthanthePDBspecifiedforaQCIaslongas
theUEhassufficientradiochannelquality.
NOTE2:Therateofnon-congestionrelatedpacketlossesthatmayoccurbetweenaradiobasestationanda
PCEFshouldberegardedtobenegligible.APELRvaluespecifiedforastandardizedQCIthereforeapplies
completelytotheradiointerfacebetweenaUEandradiobasestation.
NOTE3:ThisQCIistypicallyassociatedwithanoperatorcontrolledservice,i.e.,aservicewheretheSDF
aggregate''suplink/downlinkpacketfiltersareknownatthepointintimewhentheSDFaggregateisauthorized.
IncaseofE-UTRANthisisthepointintimewhenacorrespondingdedicatedEPSbearerisestablished/modified.
NOTE4:IfthenetworksupportsMultimediaPriorityServices(MPS)thenthisQCIcouldbeusedforthe
prioritizationofnon-real-timedata(i.e.mosttypicallyTCP-basedservices/applications)ofMPSsubscribers.
NOTE5:ThisQCIcouldbeusedforadedicated"premiumbearer"(e.g.associatedwithpremiumcontent)forany
subscriber/subscribergroup.Alsointhiscase,theSDFaggregate''suplink/downlinkpacketfiltersareknownat
thepointintimewhentheSDFaggregateisauthorized.Alternatively,thisQCIcouldbeusedforthedefault
bearerofaUE/PDNfor"premiumsubscribers".
NOTE6:ThisQCIistypicallyusedforthedefaultbearerofaUE/PDNfornon-privilegedsubscribers.Notethat
AMBRcanbeusedasa"tool"toprovidesubscriberdifferentiationbetweensubscribergroupsconnectedtothe
QualityofServiceinLTE
Page14
samePDNwiththesameQCIonthedefaultbearer.
PCCruleparameters
?QCI–QoSclassindicator
?ARP–Allocation/RetentionPriority--informationabouttheprioritylevel,pre-emptioncapability,
andpre-emptionvulnerability.ARPpriorityis1…15,1hashighestpriority.1-8areusedwithinthe
operatordomain,9-15areusedwhenroaming.
?GBR–guaranteedbitrate
?MBR–maximumbitrate
?SDF–servicedataflow
Packetsmatchingtherule(theTFT)willberoutedintoabearerthatmatchesthesettings(viatheQCI)
ofARP,GBR,andMBR.
Keyoperatordeployment&architecturedecisions
Thefollowingarekeyquestionsanetworkoperatorneedstoanswer:
1.WilldynamicPCC(flow-based)rulesbeused?ThisdramaticallyimpactsthescaleofthePCRF
deployment,theuseofDiameterroutingagents,andthesignalingloadontheevolvedpacket
core.
2.WillApplicationDetectionandControl(ADC)rulesbeused?TherichnessofcapabilitiesofthePCEF
willbethegatingfactorforservices.
3.WillstaticPCCrulesbeused?Anupstreammarkingdevicewithapplicationawarenessmaybe
needed.
4.IsQoSintheradiosufficient?Ifnot,allrulesneedtoapplytoboththeeNodeB(viatheTEIDand
PDPcontext)inadditiontoothernetworktechnologiesusingtheirownproprietarymethods(e.g.,
RSVP-TE,DSCP,MPLS-EX,…)
Whatisthe“End”inEnd-to-End?
Internetarchitecturesaregenerallybuiltaroundper-hop-behaviour,whereastraditional
telecommunicationsvoiceinfrastructureswerebuiltaroundcircuit-switching.Asaconsequenceof
thesedesignchoicestherearetradeoffsaswemigratetoLTE.Themostimportantsetoftrade-off
comesindefiningthe‘ends’inend-to-end.
Keyquestionsinclude:
?IsupstreamQoSimportant(user-equipmenttowardsInternet)
?Arecarrier-providedapplicationsincluded?
?Areover-the-topapplicationsincluded?
?Isaguaranteerequired,orisincreasedprobabilityofqualitysufficient?
?DoestheQoShavetoworkinin-networkhand-offscenariosbetweenLTEandearliertechnologies?
?DoestheQoShavetoworkinoff-networkhand-off(roaming)scenariosbetweenLTEandLTE
technologies?
?DoestheQoShavetoworkinoff-networkhand-off(roaming)scenariosbetweenLTEandnon-LTE
technologies?
?Ifthequalitycannotbeguaranteedshouldtheapplicationbedisallowed?(connectionadmission
control)
QualityofServiceinLTE
Page15
?Ifasessionisstartedinaregionwithsufficientcapacity,buttheusermovestoonewithout,isthe
sessionterminated?
?IsitsufficienttoperformtheQoSonlyinthemost-congestedpartofthenetworkandassumethe
remainderissufficientlynon-oversubscribedtonotmatter?
?IsQoSbeingusedasan‘improvement’ora‘degradement’?
?Ismobile-to-mobileQoSneeded(e.g.,push-to-talkovercellular)?
?Isthereanabilitytocontroldemandonsomeclassesofapplication(e.g.,videooptimization,
trafficmanagement)tocreateadditionalcapacity?
?Willlocalbreakoutbeusedinthehome-network?Inthevisited-network?Ifso,packetsmayflowa
differentpath.
Answerstotheabovequestionshelpnarrowthefocusontowhichandhowlayersofthenetworkare
affected,andthuswhichtechniquesareneeded.InFigure14,wecanseeastereotypicalLTEnetwork.
Ateachlevelthereareaggregationrouters,bringingtogethermultiplesources.
Figure14:Networklayers
Usuallythereismulti-pathrouting(e.g.,OSPFECMP)andasaconsequenceofpacketswitchingseveral
problemsmayarise(seeFigure15):
1.Theupstreamanddownstreampathsmaygooverdifferentlinks,orinthecaseoftheover-the-top
applications,entirelydifferenttransitserviceproviders.
2.Thepathsthatpacketsflowovermaybeunstable.
3.Latenciesmaybedifferentineachdirection.
4.Oversubscription(andthuslatency,loss,jitter)canbedramaticallydifferentineachdirection.
5.Networkingvendorsandeventechnologiescanbedifferentineachdirection.
Figure15:Typicalpacketpath
QualityofServiceinLTE
Page16
Inthecaseabove,if‘end-to-end’isdefinedassubscriber-to-subscribercontent,thenQoSmeanssome
networkengineeringoractivesignalingacrossmultipleoperatorsandtechnologies.Itwouldbehighly
wastefultoprovideguaranteesonalllinksforapossibleserviceflow.IntheexampleshownbyFigure
15,ifweassumetheserviceis1Mbpsofpeakbandwidth,thena?vemodelwouldbetocreatea1Mbps
‘constantbitrate’guaranteeonlinks1…25.Butifthereweresomewayofknowingthepacketflow,
andthepacketflowneverchanged,wewouldonlyneedthat1Mbpsguaranteeon1…6inthe
downstream.Thena?veapproachwastesfourtimesthecapacity.Amoretypicalapproachisto
guaranteethe1Mbpssolelyonlink6(orsometimeslink5…7),andengineerthe‘core’tohave
statisticalguaranteesonly.
Anotherdownsidetousingthe‘na?ve’approachisthatsignalingisrequiredtoalargenumberof
routers(alltheroutersintransit-A,transit-B,allthecorerouters,alltheaccessrouters).These
routersalmostcertainlyhavedifferentcapabilitiesandinterfaces(itislikelythe‘core’routerssupport
signalingviaBGPsolely,theedgeroutersmaysupportRADIUSCoAorCOPS,andtheroutersinthe
transitwouldbeunderdifferentadministrativecontrol,etc.).
Notethatthe3GPPPCCstandardsarewrittentoassumethereis‘negligible’lossbetweenthePCEF
andtheradiobasestation(seeNote2ofTable1).InpracticethisisanaggressiveassumptionforLTE
sincethebackhaul(S1-U)networkcanbecongested.
LTEQoSUseCases:FairshareTrafficManagement
SandvinehasalwaysworkedtoensureitsQoS-handlingcapabilitiesfunctionwellforallnetworktypes
andbetweennetworkstypes,whileeasilyadaptingtoongoingarchitecturalevolutions.Agood
exampleistheTrafficManagementproduct,whichincludesanadvancedfeature-setcalledFairshare.
SandvinehaswidelydeployedFairshareTrafficManagementincableenvironmentsusingPacketCable
MultiMedia(PCMM)prioritization.ThistrafficmanagementmechanismisdescribedinRFC6057
8
1.Identifylinksexperiencingcongestion
.PCMM
isadirectanalogof3GPPPCC,beingbasedonit(andwithanexplicitgoaltoharmonisetogetherin
Common-IMS(whichbringstogetherETSITISPAN,ETSI3GPP,3GPP2,andCableLabs).Thegeneral
theoryofoperationofFairshareTrafficManagementistodothefollowing:
2.Identifytheusersonthoselinkslikelytocausedisproportionatecongestioninthenexttime
interval
3.Reducetheschedulingpriorityofthoseusersuntileither
a.Congestiondisappears(withsomehold-downtimeorhysteresistopreventoscillation)or
b.Theuserisnolongercausingdisproportionatecongestion
Theneteffectistoshiftcongestion(andthuslatencyandloss)moretowardstheshort-termheavy
users.InDOCSIScablenetworksthisisachievedusingtheDOCSISpriorityfield(theequivalentofthe
ARPfieldin3GPP).DOCSISallows8levelsofpriority;thedefaultserviceflowisgivenpriority1,and
the‘heavyusersoncongestedlinks’areoverriddenwithadynamic,fully-wildcardrulethatgivesthem
priority0.Asaconsequence,theDOCSISschedulerprefersthepriority1usersoverthepriority0,and
thecongestionshifts.Ifwebringthisusecaseinto3GPPwerunintoaproblemthattheuser-
equipmentdoesnotsupportbeingsignaledinthesamefashionasDOCSIS,andthustheupstream
8
http://tools.ietf.org/html/rfc6057
QualityofServiceinLTE
Page17
cannotbeprioritized
9
Thesecondproblemisrecognizingwhichlink(whichmobilesector)theuserison.InDOCSISthisis
signaledwithDHCP/SNMP/IPDRprotocols.In3GPPthisisonlysignaledonbearercreation(enablingthe
userequipment)andpossiblyoninterimupdates(e.g.,UserLocationUpdate).InversionspriortoLTE,
thefixrequiresdeployingcomplexprobesintheIuB,IuPS,IuCSlinks.InLTE,itispossibletodeploy
theSandvinePolicyTrafficSwitch(PTS)intheS1-UandthusbecomeeNodeB-awareinaverysimple
fashion(theouter-IPoftheGTPtunnelistheeNodeB).Thusthethreefollowingpossiblemechanisms
existforper-sectorprioritizationinLTE:
.However,wecanperformprioritizationforcongestionmanagementinthe
downstream.
1.SignaltoaPCRFtosignaltotheP-GWtocreateadedicatedbearerwithawildcardserviceflow
(TFT).
2.Modifythetunnel-ID(TEID)tomatchonethatisstaticallycreatedontheP-GWthathasthe
requisiteQoSparameters.
3.DeployamarkingmechanismontheSGiandhaveithitastatically-provisioned,dynamicPCCrule
using,forexample,DSCPmarking.
PCRFSignaling
Inthismodel,shownbyFigure16,thePTSperformsreportingandcorrelationbasedontheouter-IPof
theGTP-Utunnel.TheFairshareTrafficManagementpolicymeasurestopusersonbusysectorsand
createssignalingviaRx(actingasanapplicationfunction).TheRxmessagecontainsthefollowing:
?MSDISDN
?SubscriberIP
?Priorityindicator(optionallybandwidth)
?Flow-identifier(wildcardedall-sourceIP,allports,overridingthedefaultTFT)
Figure16:RadioprioritisationviaPCRF
Matchingtrafficwillbede-prioritisedintheradiobytheeNodeBscheduler.
In-BandMarking(TEIDmodification)
Inthismodel,asshownbyFigure17,theFairshareTrafficManagementpolicymeasurestop-userson
busysectors,andmodifiestheTEIDoftheirtraffictomatchapre-definedbearerthatwasstatically
createdontheP-GW.Inaddition,DSCPmarkingorMPLS-EXmarkingcanbeperformedontheouter
tunneltocauseQoSprioritizationintheratiobackhaulitself.
9
InLTE,theUEcansupportmultipleprimarycontexts,butthiswouldmeanitwouldhavetounderstandinsomeproprietary
fashionhowtoroutetrafficfromonetotheother.AprimarycontexthasaseparateIPaddress.Theintentistostandardiseand
usethisforVoiceoverLTE,inwhichtheUEknowshowtoselecttherightdedicatedbearer.Thismayormaynotworkfor
genericoverthetopapplications.
QualityofServiceinLTE
Page18
Figure17:RadioprioritisationviaTEIDmodification
Matchingtrafficwillbede-prioritisedintheeNodeBradioscheduler.
In-BandMarkingSGi(DSCPModification)
Inthismodel,thereiseitherasignalingmechanisminplacefromtheS1-MME/S11interface(toteach
thePTSabouttheusertosectormapping),orasetofPTSelementsaredeployedintheS1-Utodothe
measurementpersector.APTSonSGimarkstrafficwithDSCP,andastaticruleontheP-GWcauses
thesepacketstobemappedintoadynamicallycreateddedicatedbearer(forexample,usingCisco’s
NQoSfeature).
Figure18:RadioprioritizationviaSGi
ComparisonofTechniques
Ofthethreetechniques(PCRFdynamicPCCrule,in-bandTEIDmarking,in-bandDSCPmarking)there
aredifferentstrengthsandweakness.Noneofthetechniquesreliablyhandleupstreamprioritization
duetolimitationsofcurrentuserequipment.Asaconsequence,theupstreamisbesthandledviaa
capacity-controlagentsuchastheSandvinePTS(asapolicer)orusingthe3GPPPCC‘GBR’.Providinga
maximumrateratherthanprioritizationisnotasefficientoreffective,butwillservesomepurpose.
ThePCRFwithdynamicPCCrulesmodelisthemostcomplex,requiringthemostmovingpartsandthe
highestsignalingrate.TheSGiin-bandmarking,otherthanrequiringaproprietaryconfigurationperP-
GW,willbethemostreliableandsimplesttomanage.Allthreetechniqueswillbeequallyeffectiveat
over-the-airradioprioritization,andthiseffectivenesswillbeafunctionoftheeNodeBscheduler
solely.
S1-Uprioritizationofbothinner-andoutertunneloffersthebestoverallperformanceasithandles
bothbackhaulandradiocongestion.Sandvine’ssupportforthisusecaseisuniquelyenabledbythe
SandScriptpolicylanguageandthefreeformpolicycreationenvironmentitprovides.
QualityofServiceinLTE
Page19
AutomatedQoSControlforMobileNetworkCongestionManagement
Sandvine’sFairshareTrafficManagementusesanadvancedfeaturecalledtheQualityGuardcongestion
responsesystem.QualityGuardcontinuouslymeasuressubscriberQoEinrealtimetodetectcongestion
intheaccessnetwork,andthenautomaticallymanagesQoStoremovecongestionbyshapingtraffic
classifiedas“low-value”(heavyshort-termuserswhoarecontributingtocongestion,ornon-real-time
applicationssuchasemailandbulkdownloads,oracombinationofboth).
Earlieritwasnotedthatasthroughputincreasesonanodeorrouter,latencyincreasesduetothe
growingqueuedelayandthe‘bursty’natureofTCP.Theincreaseisrathermarginal,butproportional
totheincreaseinbandwidth.Asthethroughputapproachescapacity,latencybeginstoincrease
exponentiallyuntilitreachesafinaltippingpointwheretheelementexperiencescongestivecollapse.
Whenanaccessnodeisnearoratcapacity,subscribersexperiencethegreatestdeteriorationofQoE.
Figure19showstherelationshipbetweenthroughputandlatencyontheroadtothecongestive
collapseofanaccessresource.
Figure19-RelationshipbetweenThroughputandLatency
QualityGuardusesaccessroundtriptime(aRTT)tomeasurereal-timesubscriberQoE,andthisisused
astheinputforaclosed-loopcontrolsystemthatcontinuouslyandautomaticallyworkstomaintainthe
optimumshapedtrafficoutputduringtimesofcongestion.Thisisthemaximumthroughput,ortarget
goodput,thattheaccessresourcecanmaintainwhilestillprovidingagoodQoEtothe95-99%of
subscribersthatfallintothehigh-valuetrafficcategory.Fromatechnicalstandpoint,QualityGuard’s
goalistomaintaintheoptimalgoodputfortheaccessresource,whichinmobilenetworksisa
constantlymovingtargetduetothevariablenatureofacell’smaximumcapacity.
Congestive
collapse
QualityofServiceinLTE
Page20
Figure20–MaximizingsubscriberQoEandinfrastructurelifetime
Usingreportsgeneratedbyasetofcongestion-relatedbusinessintelligencecalledQualityWatch,and
drivenbySandvine’sstandardreportinginterface,NetworkDemographics,thefollowingthree
graphicalreportsdemonstratethepositiveeffectofQualityGuard.
Figure21showstheneteffectofQualityGuardonLayer-7OTTbandwidthforaresourceexperiencing
massivecongestionproblems.Whenwebbrowsingtrafficbeginstoincreaseandreal-timesubscriber
QoEfallsbelowaconfiguredbenchmark,QualityGuardshapesthebulktransfertrafficofsubscribers
currentlycontributingtothecongestionconditionwhilecreatingcapacityfortheother95-99%ofusers
alsoattemptingtousetheresource.
Figure21–Trialresults–verifyingthedesiredeffectofQualityGuardonbandwidth
Lookingatthesameresultsfromadifferentperspective,Figure22showsQualityGuard’seffecton
latencyintheformofaRTTmeasurements,andFigure23showstheeffectonthecalculatedquality
score.
QualityGuard
enforces
QualityofServiceinLTE
Page21
Figure22–Trialresults–verifyingthedesiredeffectofQualityGuardonhigh-valuelatency
Figure23–Trialresults–high-valuelatencyexpressedasaqualityscore
ConclusionsandRecommendations
1.Anoperatorshoulddefineend-to-endtoincludetheradioscheduler(eNodeB)andthebackhaul,
andoverprovisiontheremainderofthenetworktoprovideprobabilisticguaranteesonly.
2.It’simportanttounderstandthelimitationsofboththebackhaulandchoseneNodeBequipment,in
particularthenumberofqueuessupported,andwhethertheyarestrict-priority(starvinglower
priorityflows)orweighted-fair.
3.Avoidtheuseofguaranteedbitrateclasses(mediaservicesarerarelyconstantbitrate,voiceuses
silencesuppression,audioisadaptivebitrate,videoishighlyvariablebasedonsourcecontent).
4.Concentrateonasinglenetworktechnologyfirst:hand-offconditionsbetweenHSPA<Eor
CDMAandLTEwillleadtoseverelimitationsinboththenumberandrichnessofserviceflows.
5.Focusonper-hopbehaviourandmarkingratherthan‘circuit’-basedtechniques.Inparticular,avoid
theuseofsignalingserviceflowsforover-the-topservicesduetotheirshort-lifetimeandhigh-
speed.
Copyright?2013Sandvine
IncorporatedULC.Sandvineand
theSandvinelogoareregistered
trademarksofSandvineIncorporated
ULC.Allrightsreserved.
EuropeanOffices
SandvineLimited
Basingstoke,UK
Phone:+4401256698021
Email:sales@sandvine.co.uk
Headquarters
SandvineIncorporatedULC
Waterloo,OntarioCanada
Phone:+15198802600
Email:sales@sandvine.com
2013-11-22
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