Q oS in IP N etw orks:an industria l v iew point

In ternationa l W orkshop on:“Q oS in M ultiserv ice IP N etw orks”

Rom e, 24-26 January 2001

Serg io R . Treves

A lcate l

S . Treves

Sum m ary

▼ N etw ork m ode l

▼ Param eters and requ irem ents fo r Q oS

▼ R eference netw ork con figura tions fo r End-to -End Q oS

▼ M ain Q oS techn iques and netw ork arch itectu res

▼ C onclus ions

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N etw ork M odelN etw ork M odel

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N et-Econom y B usiness m odel

InternetService

Prov iders

(IS Ps)

A pplicationS erv ice

P rov iders (A S P s)

Retail

C onsum er

En terprise

C ost / Bandw id thVa lue AddedApp lica tions

M u ltiM ed iaB roadbandQ oS

M obileS erv iceP rov iders(M S P s)

G S MG P R S

U M TSE D G E

C om petitiveA ccessP rov iders(C A P s)

C ab le

LM D SP O N

W D M

S atelliteA D S LV D S L

B ackbone S erv iceP rov iders (B S Ps)

IP / M P LSD W D M

S oH o

S M E

C orpora te

C PEC PE A ccess E dgeA ccess E dge C oreC ore

Wholesale WholesaleRetail

E stab lished Serv iceP rov iders (ES P s)TD M

N B W ire linexD S L

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N ext G eneration N etw ork m odel

NetworkIndependent

Services

Call Server

Services

Sign. Gway

Gateways

Legacy NetworkM edia

Legacy NetworkS igna lling/Service

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C om m unication Scenarios

▼ PC to PC▼ PC to G atew ay

PSTN

PSTN IP

▼ G atew ay to G atew ay

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Param eters and R equirem entsParam eters and R equirem entsfor Q oSfor Q oS

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Q uality of Serv ice (Q oS)

▼ Q uanta tive m easure of the degree of satis faction perce ived byan end user (custom er) o f a serv ice, expressed by m eans ofQ oS param eters that can be m easured inc lud ing:

◗ ava ilab ility◗ erro r perfo rm ance◗ response tim e◗ los t ca lls due to netw ork congestion

▼ Serv ice P rov ide rs m ay guaran tee a particu la r leve l o f Q oS tothe ir custom ers by m eans o f a Serv ice Leve l Agreem ent (SLA)

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Q uality of Serv ice A spects

▼ N etw ork Perform anceaspect

▼ End-U ser aspect

❑ Tra ffic pe rfo rm ance: th roughtpu t, de lay& jitte r, loss

❑ E rror perfo rm ance❑ D ependab ility : ava ilab ility , re liab ility ,

m a in ta inab ility

❑ S ervice re ta inab ility (p rovis ion for arequested du ra tion)

❑ S ervice in teg rity (p rov is ion w ithout excess iveim pa irm en ts)

❑ S ervice accessib ility (w hen requested)

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Layer-specific Q oS for Vo ice

App lica tion layer

Te lephony se rv ice = tw o-w ay

transport o f vo ice signa ls a t a deside red qua lity R

T ransport se rv ice = one-w ay

transport o f vo ice packe ts

Encod ingFECPacke tiza tion

D ejitte ringD ecod ing

IP N etw ork layer

E gresspo in t

Ing resspo in t

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R elevant Q oS Param eters

▼ IP N etw orkIP N etw orkLayerLayer

▼▼ A pp lica tionA pp lica tionLayerLayer

• Ingress-to -Egress delay

• Ingress-to -Egress jitter

• Ingress-to -Egress packet loss

• M outh-to -Ear de lay

• D istorsion of the vo ice s igna l

- encod ing /decod ing- packetisa tion de lay- de jitte ring loss

due to:

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U M TS Q oS C lassesdefined by 3G PP (standards TS 23 .107)

Real-T im eConversationa l

Rea l-T im eStream ing

Non Real-T im eIn teractive

Non Real-T im eBackground

stringen t

constra ined

no

no

stringen t

constra ined

no

no

no

no

yes

yes

Y es(C B R , V B R )

Y es(V B R )

N o(V B R )

N o(A B R )

Transfer

D elay

requirem ent

Transfer

D elay

V aria tion(J itte r)

Low b it

erro r rate

G uaran teed

bit rate

Typical

applications

V oIP , V ideo-conferenc ingA ud io-conferenc ing

B roadcast se rv ices(aud io , v ideo), N ew s, S ports

W E B brow sing, In teractiveC ha t, G am es, m -com m erce

E -m ail, S M S , databasedow nloads

C haracteristics

Traffic type

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Q oS C lasses defined by ETSI T IPH O N

C lass C lass 4: Best(bette r than toady’s

P S TN /IS D N )

O vera ll SpeechTransm ission Q ualityRating (R ) G .109

90≤R<100

C lass 3: H igh(equ iva lent to today’s

P S TN /IS D N )

C lass 2: M ed ium(equ iva lent to today’s

w ire less netw o rks)

C lass 1: Low(s ign ificantly im pa ired,

bu t usab le)Param eter

End-to-End Delay(m s)

< 100

L isten ingSpeech Q uality(one way, nonconversationa l)

Bette r thanG .711

Equiva lent orbette r thanG .726 at 32 kb/s

Equ iva lent orbette r thanG SM -FR

Undefined

80≤R<90 70≤R<80 60≤R<70

< 100 < 150 < 400

TIP H O N = Te lecom m unica tion Internet P ro toco l H a rm onization O ver N etw o rks

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R eference N etw ork C onfigurationsR eference N etw ork C onfigurationsfor E2E Q oSfor E2E Q oS

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C urren t G eneration N etw ork

N etw orkP ee ring

E S P /M S PC A P /IS P

vo iceda ta

POTSBA, PRA

ADSLHFC

POTSBA, PRA

da ta

C orpora te and R esidentia l C P E

IS P /IA P

‘In ternet Backbone’and other ‘Carrier Backbones’

PacketNetw ork

PacketNetw ork

B B A ccessN etw ork

P O P

POTSBA, PRA

POTSBA, PRA

ADSLHFC

da ta

vo ice

da ta

C orpora te and R esidentia l C P E

P O PPO P P O PP O PPO P

GSMGPRSUM TS

GSMGPRSUM TS

Sw itchedC ircu it N etw ork

(SC N )E S P /M S P

B B A ccessN etw ork

B S P

Sw itchedC ircu it N etw ork

(SC N )

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N ext G eneration N etw ork (N G N ):generic reference configuration

P acke t N etw ork (P N z)O perator z

xz yzxyO perator x

W x

W x

T*x

T x

Sw itchedC ircu it

Network(SCN x)

U xCustom erPrem ises

(CP x)

NT

TE

O perator y

V y

W y

T y

T*x

Sw itchedC ircu it

Network(SCN y)

U yCustom erPrem ises

(CP y) TE

NT

PacketNetwork(PN x)

AccessNetwork(AN x)

PacketNetwork(PN y)

AccessNetwork(AN y)

CPN CPN

U*xU *x

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N ew G eneration N etw orks:R eference C onfigurations

PN = P acke t N e tw ork (IP , A TM , M PLS)AN = A ccess N etw ork (AD S L, H FC , PO N +VD SL, LM D S, U TR A N )SC N = S w itched C ircu it N etw ork (PSTN , ISD N , PLM N )x, y, z= D ifferen t ope rators

A N x

S C N x

A N x

A N x

S C N x

A N x

P N x

P N x

P N x

P N x

P N x

P N x

P N z

P N z

P N z

P N y

P N y

P N y

P N y

P N y

P N y

A N x

S C N y

S C N y

A N y

S C N y

S C N y

tx u x

tx u x

tx u x

tx u x

tx u x

tx u x

vx

vx

vx

w x

vx

w x

xz

xz

xz

yz

yz

xy

xy

xy

yz

vy

w y

vy

w y

w y

w y

ty u y

ty u y

ty u y

ty u y

ty u y

tyu y

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M ain Q oS Techn iquesM ain Q oS Techn iques

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Q oS A rch itec turesS ing le IP transport provider (1 )

IP

In tserv

▼ C ontro l o f IP ne tw ork Q oS param ete rs▼ Feasib ility o f In tserv E2E▼ D im enson ing o f p re -prov is ioned Trunks

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Q oS A rch itec turesS ing le IP transport provider (2 )

IP

D iffserv

▼ E2E D iffse rv

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Q oS A rch itec turesS ing le IP transport provider (3 )

IP

In tserv

D iffserv

▼ In tserv in the access/edge and D iffse rv in the core

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Q oS A rch itec turesM u ltip le IP transport providers

▼ C onnection path crossing m ultip le transport p rov iders▼ In te rw ork ing of m ultip le com binations of Q oS contro l a rch itectu res

IP

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In tServ vs D iffServ Techniques

A davantages D isadvantagesFea tures

N etw orkTechn ique

- S tandard ized E2E s igna llingpro toco l (RSVP)

- Requested serv ices offe red(CL and G S )

- RSVP not sca lab le and com plex due toneed for core routers to m ain ta in contro ls ta te for each flow

- Com m on agreeem nt am ong all ISP ’sneeded for E2Econnections (on RSVP use)

- Not su itab le for E2E Q oS

- Sca lab le (focusing on tra fficaggregates w ith sim ila r servicerequ irem ents)

- Requested serv ices offe red

- No signa lling pro toco l to check theava ilab ility o f resources E2E

- Not su itab le for E2E Q oS

- Sca lab le (D iffServ)- S tandard ized In tServ/RSVP

signa lling pro toco l fo rin ter-dom ain

- Com m on agreem ent needed betweenISP ’s on the use of In tServ /RSVP forin ter-dom ain signa lling

In tServ

D iffServ

IntServ in the access& D iffServ in the core

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In tServ m apped on D iffServ

Sender A

accessnetw ork ER1

backbonenetw orkBR1

BR2

accessnetw ork

ER2

R ece ive r Y

In tServD iffServ

In tServ

In tse rv m app ing on D iffserv

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Fixed p ipes m apping In tServ on D iffServ

In tserv flow s en terthe IP backbone th roughborder rou ter BR 4:

1 ) pe rfo rm s the In tserv processing2 ) checks if the re a re su ffic ient am oun t

o f resou rces ava ilab le in the IP backbone .If the flow is accepted, then a ll packe tsa re sent to BR 2

Intserv flow s leavethe IP backbonethough border rou terBR 2

S tatica lly con figured pipes w ith acerta in am ount of bandw id th fromeach ingress rou te r tow ards eachegress rou te r:

* M PLS w ith E -LSPs or L-LSPs* ATM PVC s

BR4

BR3

BR1

BR2

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E2E Q oSA generic C om m unication Scenario (1)

In tse rv/R SVP (in ter-dom a in s igna ling )

ATM Intse rvD iffse rv 1 D iffse rv 2

D iffserv 1 = fixed p ipesD iffserv 2 = proprie ta ry so lu tionorD iffserv 1 = R SVP aggregationD iffserv 2 = 2 b it resource a lloca tion schem eor ...

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E2E Q oSA generic C om m unication Scenario (2)

In tse rv/R SVP (in ter-dom a in s igna ling )

D iffse rv 1 D iffse rv 4D iffse rv 2 D iffse rv 3

D iffserv 1 = fixed p ipesD iffserv 2 = proprie ta ry so lu tionD iffserv 3 = over-prov is ionedD iffserv 4 = R SVP aggregation

N o per-flow sta te in :core rou ters o f the 4 dom ainsborder rou ters o f dom ain 3

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C onclus ionsC onclus ions

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Q oS in N ext G eneration N etw orks

▼ Focus sh ifting from ind iv idua l bu ild ing b locks to E2E netw orkconfigura tions in re la tion to :

◗ C om m unica tion scenarios

◗ N um ber o f the IP transport p rov iders invo lved◗ Q oS contro l a rch itec tu re in use

◗ N um ber o f the IP Te lephony S ervice P rovide rs invo lved

◗ S igna ling , ca ll and A AA contro l a rch itec ture in use

▼ F ixed (w ire line) and m obile (w ire less) ne tw ork environm ents

▼ H etereogeneous classes of tra ffic w ith d iffe ren t Q oSrequ irem ents

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End-to -End Q oS “open” Issues

▼ R eference netw ork configura tions (standard iza tion)

▼ Arch itectu ra l enhancem ents fo r Q oS support (en forcem entand po lic ing)

▼ Protoco l extens ions for Q oS support

▼ E2E Q oS in heterogeneous environm ents:◗ seam less contro l a rch itec tu re for fixed and m obile◗ in te rw o rk ing o f m ulti-adm in is tra tive dom ains (m ultip rov iders)◗ in te roperab ility o f d iffe ren t ne tw orking techno log ies

▼ Q oS support in w ire less subnetw orks:◗ loca tion dependent erro rs◗ tim e verying channe l capacity

▼ D ynam ic custom er cho ice of C lass of Serv ice-29-