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i3 FORUM

QoS Control & Monitoring

The i3 Forum approach for QoS Control for

international voice services

presented by

Ian Campbell, PTGi ICS

May 26, 2011

Agenda

QoS

Busin

ess D

rivers

Use C

ases

Passiv

e a

nd A

ctive M

easure

men

ts

Curr

ent

i3 F

oru

m a

pp

roach (

RT

CP

)

i3 S

olu

tion R

equ

irem

ents

Pro

posed S

olu

tio

n:

QoS

Aggre

gation

Pro

posed S

olu

tio

n:

Med

ia L

oop

back

Pro

posed S

olu

tio

n:

SIP

QoS

report

ing

Tra

nsport

Para

mete

rs:

•R

ound-T

rip D

ela

y

•Jitte

r

•P

acket

Loss

Serv

ice P

ara

mete

rs:

•M

OS

CQ

E–

Mean O

pin

ion S

core

, C

onvers

ational Q

ua

lity E

stim

ate

d

•ALOC

–A

vera

ge L

ength

of

Call

(a.k

.a.

AC

D)

•ASR

–A

nsw

er

Seiz

e R

atio

•N

ER

–N

etw

ork

Eff

icie

ncy R

atio (

corr

ects

for

user

behavio

r)

•P

GR

D –

Post G

ate

wa

y R

ing D

ela

y (

dela

y t

o r

eceiv

ing a

lert

ing)

Curr

ent i3

Foru

m Q

oS

Measure

ment P

ara

mete

rs

QoS Business Drivers

IP Q

ualit

y

This presentation focuses on the measurement of MOS; transport

parameters are also measured by the methods discussed.

SLA

Enfo

rcem

ent

•M

OS

an im

port

ant K

PI, p

art

icula

rly for

GS

MA

IP

X

•S

erv

ice p

rovid

er

custo

mers

now

educate

d o

n M

OS

Routing D

ecis

ions

•M

OS

an im

port

ant com

ple

ment to

AS

R/N

ER

/ALO

C

•Q

ualit

y p

lays a

n im

port

ant part

in L

CR

decis

ions

•V

oIP

qualit

y r

ecogniz

ed a

s h

ard

with o

nly

AS

R/N

ER

/ALO

C

Netw

ork

Opera

tions

•M

easure

ment of in

tern

al M

OS

essential

•M

OS

info

rmation u

sefu

l fo

r dia

gnostics

The im

port

ance o

f accura

te M

OS

for

inte

rnational vo

ice

QoS Business Drivers

QoS Use Case (1): Bilateral

VoIP

VoIP

Service

Provider A

Service

Provider B

Carrier A

IP netw

ork

Carrier B

IP netw

ork

CHF

CHF

Border

Functions

Border

Functions

Border

Functions

Border

Functions

Internal QoS Domain

Internal QoS Domain

Downstream Service QoS Domain

Bilateral QoS Domain

•C

arr

ier

A k

no

ws q

ualit

y a

cro

ss its

Inte

rnal Q

oS

Do

ma

in

•C

arr

ier

A w

an

ts t

o k

now

qualit

y a

cro

ss B

ilate

ral Q

oS

Dom

ain

•Q

ualit

y a

cro

ss D

ow

nstr

eam

Serv

ice Q

oS

Do

main

to e

nd u

ser

not

needed

QoS Use Case (2): IPX

Mobile

Provider A

Mobile

Provider(s)

Carrier A

IPX netw

ork

Carrier B

IPX netw

ork

CHF

CHF

Border

Functions

Border

Functions

Border

Functions

Border

Functions

Internal QoS Domain

Internal QoS Domain

Downstream Service QoS Domain

IPX QoS Domain

•M

obile

Pro

vid

er

wants

to e

nsu

re S

LA

com

plia

nce o

f C

arr

ier

IPX

serv

ice

•C

arr

ier

A k

no

ws q

ualit

y a

cro

ss its

Inte

rnal Q

oS

Do

ma

in

•C

arr

ier

A w

an

ts t

o k

now

qualit

y a

cro

ss IP

X Q

oS

Dom

ain

for

SLA

com

plia

nce

•Q

ualit

y o

f D

ow

nstr

eam

Serv

ice Q

oS

Dom

ain

not

usefu

l fo

r S

LA

co

mplia

nce

IMS

/TD

M

IMS

/TD

M

IMS

/TD

M

QoS Use Case (3): Global Wholesale

VoIP

VoIP

Service

Provider A

Service

Provider B

Carrier A

IP netw

ork

Wholesale

Netw

orks

CHF

Border

Functions

Border

Functions

Internal QoS Domain

Wholesale QoS Domain

Downstream Service QoS Domain

Wholesale QoS Domain

•C

arr

ier

A w

an

ts t

o k

now

qualit

y o

f w

hole

sale

route

to d

ow

nstr

eam

SP

B

•C

arr

ier

A k

no

ws inte

rnal qualit

y b

ut not

qualit

y a

cro

ss w

hole

sale

clo

ud

•Q

ualit

y a

cro

ss D

ow

nstr

eam

Serv

ice Q

oS

Do

main

to e

nd u

ser

ma

y b

e u

sefu

l

?

?

?

Active & Passive Measurement

Curr

ent i3

Foru

m A

ppro

ach:

•S

pecifie

d in t

he T

echnic

al In

terc

onn

ect

Mod

el docum

ent

•S

pecifie

s M

OS

CQ

Eb

y p

assiv

e m

easure

men

t

•C

alc

ula

ted f

rom

the R

-Facto

r (I

TU

-T P

.10/G

.107)

•R

-Facto

r itself c

alc

ula

ted u

sin

g t

he E

-model, u

sin

g:

–O

ne-w

ay d

ela

y

–Jitte

r

–P

acket

loss

–C

odec im

pair

ment

(G.7

11 =

0 im

pairm

ent)

•D

ela

y,

jitte

r, lo

ss f

rom

RT

CP

sender

and r

eceiv

er

rep

ort

s

•R

TC

P m

easure

d f

rom

ingre

ss S

BC

to d

ow

nstr

eam

RT

P e

nd p

oin

t

Current i3 Approach (RTCP)

Current i3 Approach (Problem)

VoIP

VoIP

Service

Provider A

Service

Provider B

Carrier A

IP netw

ork

Carrier B

IP netw

ork

CHF

CHF

Border

Functions

Border

Functions

Border

Functions

Border

Functions

Internal QoS Domain

Internal QoS Domain

Downstream Service QoS Domain

Bilateral QoS Domain

•P

roble

m 1

: R

TC

P r

eport

sou

rce a

mbig

uity b

etw

een R

TC

P S

ourc

e 1

&2

→C

arr

ier

bo

rde

r fu

nction d

oes n

ot know

what

it is m

ea

suring

!

•P

roble

m 2

: R

TC

P m

easure

men

t to

end u

ser

devic

e is n

ot

usefu

l

→Q

ualit

y a

cro

ss t

he c

arr

ier

dom

ain

s n

eeded, end S

P q

ualit

y u

se

ful but no

t needed

TD

MMedia

Gateway

RTCP Source 1

RTCP Source 2

Problems 1& 2 exists in all use cases, however depending on the

relationship between carriers RTCP can be made to work, e.g. in a

controlled Bilateral case

Contr

olla

ble

or

identifiable

measure

ment dom

ain

(s)

Active o

r P

assiv

e

Pro

vid

e M

OS

CQ

Eand o

ptionally

MO

SLQ

O

Reasonable

deplo

ym

ent overh

ead

Pre

fera

bly

inte

gra

ted into

exis

ting e

quip

ment

Assis

t w

ith S

LA

monitoring a

nd tro

uble

shooting

Handle

at le

ast B

ilate

ral and IP

X u

se c

ases

Not vendor

pro

prieta

ry / b

road industr

y s

upport

Recogniz

ed s

tandard

i.e

. IE

TF

/IT

U-T

Ideal R

equirem

ents

:

I3 Solution Requirements

Each c

arr

ier

monitors

qu

alit

y a

cro

ss t

heir inte

rnal Q

oS

dom

ain

usin

g

their c

hose

n m

echan

ism

e.g

. pro

be s

erv

ers

or

RT

CP

Carr

iers

sh

are

info

rmatio

n:

•D

irectly w

ith e

ach o

ther

•In

to a

3rd

part

y m

ain

tain

ed Q

oS

data

base

Som

e p

ossib

le issues:

•M

ay n

ot

scale

be

yon

d t

he b

ilate

ral case

•W

ho r

uns a

nd a

dm

inis

ters

ce

ntr

al data

base if

pre

sent?

•C

arr

iers

ma

y n

ot

wis

h t

o s

ha

re info

rmatio

n

•N

ot

suitable

fo

r tr

ouble

sh

ooting o

pera

tions in r

eal tim

e

Aggregating Internal QoS Domain m

easurements

Proposed Solution: QoS Aggregation

“An E

xte

nsio

n t

o t

he S

essio

n D

escription P

roto

col (S

DP

) fo

r M

edia

Loop

back”,

Ma

rch 2

011

Active m

echan

ism

wh

ich a

llow

s p

roposa

l of

media

path

loo

pback

with 3

modes:

•E

ncapsula

ted s

ourc

e R

TP

sent

back to s

ender

•D

irect lo

opback b

y c

op

yin

g inbound R

TP

back to s

end

er

•M

edia

loopback b

y s

endin

g a

udio

back to s

ender

SD

P t

o p

ropose loop

back s

essio

n t

o d

estin

ation ‘m

irro

r’

Specifie

s u

se o

f R

TC

P/R

TC

P-X

R f

or

carr

yin

g o

f lo

ss,

dela

y,

jitte

r and o

ther

info

rmation.

Can g

enera

te M

OS

CQ

E ,

ma

yb

e M

OS

LQ

O

Requ

ires s

essio

n t

o b

e c

reate

d t

o a

kno

wn t

est

poin

t, i.e

. a test

num

ber

IETF Draft: draft-ietf-m

music-loopback-15

Proposed Solution: Media Loopback (1)

Proposed Solution: Media Loopback (2)

VoIP

VoIP

Service

Provider A

Service

Provider B

Carrier A

IP netw

ork

Carrier B

IP netw

ork

CHF

CHF

Border

Functions

Border

Functions

Border

Functions

Border

Functions

Internal QoS Domain

Internal QoS Domain

Downstream Service QoS Domain

Bilateral QoS Domain

TD

MMedia

Gateway

Border

Functions

`̀

Me

dia

Lo

opba

ck

Sou

rce

Me

dia

Lo

opba

ck M

irro

r 1

Num

be

r: +

39

12345

678

Me

dia

Lo

opba

ck M

irro

r 2

Num

be

r: +

32

56789

1011

•T

o m

easure

the q

ualit

y a

cro

ss t

he B

ilate

ral Q

oS

Dom

ain

, C

arr

ier

A c

reate

s a

loop

back

sessio

n to the B

ord

er

Functions in S

erv

ice P

rovid

er

B

Very

larg

e n

um

ber

of

loop

back s

essio

ns m

ay b

e r

equir

ed:

•C

om

ple

te c

overa

ge c

ould

de

pend o

n n

etw

ork

str

uctu

re i.e

. lo

catio

n a

nd n

um

ber

of

Bord

er

Function e

lem

ents

–N

2 p

roble

m?

•B

ilate

ral case p

roba

bly

work

able

, IP

X c

ase p

robab

ly d

ifficult,

Glo

bal W

ho

lesale

case p

roba

bly

im

possib

le!

Loop

back m

irro

r (t

est

poin

t) locations w

ill r

equire t

o b

e s

ha

red:

•S

hare

d lis

t ne

eds t

o b

e e

sta

blis

hed

•In

form

ation o

n t

est

num

ber

and s

yste

m loca

tion im

port

ant

•S

ecurity

co

ncern

s:

–U

ser

security

an

d a

ccess c

ontr

ol

–P

art

ne

r only

access in IP

X

–In

tern

al netw

ork

str

uctu

re m

ay n

eed to b

e r

eveale

d

Not

measuri

ng s

am

e p

ath

as a

ctu

al tr

aff

ic,

possib

le f

raud

Some possible issues:

Proposed Solution: Media Loopback (3)

Solu

tio

n w

ou

ld u

se o

ne o

f th

e a

vaila

ble

SIP

message t

ypes:

•P

UB

LIS

H

•IN

FO

•N

OT

IFY

RT

CP

/RT

CP

-XR

info

rmatio

n p

rovid

ed i.e

. lo

ss,

dela

y,

jitte

r fo

r M

OS

CQ

E/ R

-Facto

r calc

ula

tion

Info

rmation c

ould

be s

ent

aft

er

SIP

BY

E m

essage

Appro

ach s

imila

r to

IE

TF

RF

C6035 “

Sessio

n I

nitia

tion P

roto

col

Event

Package

for

Voic

e Q

ualit

y R

eport

ing”,

Novem

ber

201

0

Report

s w

ould

conta

in a

n ide

ntifier

of

the r

em

ote

genera

tor

Report

s c

ou

ld b

e s

ent

from

in

term

edia

te s

yste

ms in c

all

path

Contin

ues t

o w

ork

even if

RT

CP

is b

roken b

y inte

rmedia

te s

yste

ms

Using SIP Signaling to carry QoS Reports

Proposed Solution: SIP QoS Reporting (1)

Proposed Solution: SIP QoS Reporting (2)

VoIP

VoIP

Service

Provider A

Service

Provider B

Carrier A

IP netw

ork

Carrier B

IP netw

ork

CHF

CHF

Border

Functions

Border

Functions

Border

Functions

Border

Functions

Internal QoS Domain

Internal QoS Domain

Downstream Service QoS Domain

Bilateral QoS Domain

TD

MMedia

Gateway

Border

Functions

Qu

alit

y

Co

llecto

r

•T

o m

easure

the q

ualit

y a

cro

ss t

he B

ilate

ral Q

oS

Dom

ain

, C

arr

ier

A u

ses r

eceiv

ed Q

oS

report

ing info

rma

tion fro

m t

he S

P B

Bord

er

Function a

t th

e ingre

ss B

ord

er

Function

SIP

Qo

S R

epo

rts

Sig

nific

ant

ove

rhead m

ay b

e c

reate

d

•Larg

e n

um

ber

of

additio

nal S

IP m

essages

•C

om

putin

g o

f qualit

y info

rmation m

ay b

e p

rocessor

inte

nsiv

e

•D

ecid

ing w

hic

h Q

oS

Report

s t

o u

se m

ay b

e c

om

ple

x

•O

verh

ead m

ay b

e t

oo m

uch f

or

Glo

bal W

ho

lesale

use c

ase

Sourc

e o

f Q

oS

Report

s c

ould

still

be u

ncert

ain

:

•Is

the s

ourc

e m

ark

ed in r

epo

rt r

elia

ble

?

•S

ourc

e ide

ntification w

ould

re

quire r

ule

s

•N

etw

ork

s w

ou

ld s

till

have t

o r

eveal lo

catio

ns a

nd t

opolo

gy

•S

ourc

e c

ould

be f

aked f

or

fraud p

urp

oses

Some possible issues:

Proposed Solution: SIP QoS Reporting (3)

The industry will need to invest in solving it and should expect

some return on investment for this.

We will work with members, standards bodies and vendors to

identify solutions over the coming work cycles.

Proposed solutions and contributions are welcome.

The i3 Forum is studying a solution for this problem

Summary

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w.i3fo

rum

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i3 FORUM

Thank You!