ftth, access and triple-play testing urbino 2011 · ftth, access and triple-play testing ... failed...

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FTTH, Access and

Triple-Play Testing

Alfonso DomesiBusiness Development Manager

Access BU

rev.1.0, February 2011

Urbino 2011

Part 1

Last, but not least

“Last mile”

2

Proprietary and Confidential 3

Once upon a time…


Copper was first choice

BASIC COPPER PAIR TERMINOLOGY› Tip & Ring / A & B

› Ground / Earth

› CO Battery

› Wire Gauges (0.3, 0.4, 0.5, 0.6 mm) Wire Pair (or copper pair)

Ring

Tip

48 - 52VDC

-

+

RING

TIP

26 AWG

24 AWG

22 AWG

19 AWG

3


Loop Plant: any thing is possible


Loop Plant: any thing is possible

4


Switch on the light


FIBER IS MADE OF DIELECTRIC MATERIAL, CONSISTING OF CORE AND CLADDING, THAT ALLOWS TOTAL INTERNAL REFLECTION OF LIGHT FOR PROPAGATION.

Coating

Cladding

Core

8mm125 mm 250mm

IOR nR

IOR nI

Fiber ‘expensive’ alternative (?)

5


Fiber Plant: any thing is possible


The Fiber & Copper Co. gives a great flexibility to operators

6


FTTC: Just an example

Part 2

Evolution of the needs

Need an evolution

7


New app every day


8


Access technology growth

1958 1990 1995 2005

ISDN

128 Kbps

HDSL

2 Mbps

VDSL2

100 Mbps

ADSL

8 Mbps

ADSL2+

24 Mbps


John Cioffi, now a Stanford Professor, founded Amati and developed

Discrete Multi-Tone technology (DMT) based equipment that in 1993 had

dramatically better results than all competitors in Bellcore testing and

became the most common standard.

New era for the copper pair

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Separates the signal

into multiples

sub-carriers (bins)

Each bin transports a piece of the

digital information

Self-adaption to the

quality of each sub-

carrier

Well defined bandwidth between

Downstream and

Upstream

The idea behind DMT


› Number of Sub-Carrier (SC) = 256 … 4096

› SC are centered at f= 4.3125 kHz

› SNR (Signal-to-Noise-Ratio) is the key

› Dynamic Rate Adaptation

› Max number of bit per bin is 15

› Complex QAM and FFT technologies

Some DMT figures

ITU-T Rec. G.992.3 (01/2005) cp. 8.12.3.3

The signal-to-noise ratio SNR(f) for a particular subcarrier is a real value which shall

represent the ratio between the received signal power and the received noise power for

that subcarrier.

10


Flexibility, it is possible to ―switch off‖ single SC

Bit Loading, more information is sent in the SC with the best SNR

DMT bit loading concept

Part 3

Test challenge

“IPTV services”

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0

20

40

60

80

100

120

140

160

CY08 CY09 CY10 CY11 CY12 CY13

Su

bsc

rib

er

(M)

Telco IPTV Subscribers by Type CY08-CY13

Pure IPTV Hybrid IPTV/over-the-air Hybrid IPTV/QAM

IPTV Growth

CY08 CY09 CY10 CY11 CY12 CY13

Telco IPTV Subscribers by Region CY08-CY13

North America EMEA APAC CALA

Adoption of

IPTV

Over-the-top

video is not

IPTV


IPTV Ecosystem

http://www.directv.com.br/imagens/logo_canais/logo_rai_gd.jpg

http://upload.wikimedia.org/wikipedia/en/thumb/3/32/Msnbc.jpg/200px-Msnbc.jpg

12


1Digitizing

Analog content

2Encoding

Digital video

3Encapsulating in

IP packets 4Transporting

IP video content

5Removing content

from IP packets

6Decoding

digital content

7Converting

to analog

IPTV: 7 steps video process


Digital Encoding Compression Rates

PAL Standard Definition TV video High Definition TV video

Digital Video Encoding /

Compressing format

Pre-compressed

Bandwidth Requirement

Compressed Bandwidth

Requirement

Pre-Compressed

Bandwidth Requirement

Compressed Bandwidth

Requirement

MPEG2 250 Mbps 2-6 Mbps 1250 Mbps 8-20 Mbps

MPEG4

(H.264 part 10)250 Mbps 1-3 Mbps 1250 Mbps 4-10 Mbps

VC-1 250 Mbps 1-3 Mbps 1250 Mbps 4-10 Mbps

SD image = 25 frames per sec X (576 rows X 720 columns X 24 bits)

HD image = 25 frames per sec X (1080 rows X 1920 columns X 24 bits)

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Compression

based on processing

8x8 pixel blocks

MPEG-2 video coding


Only changing area have to be coded

MPEG-2 video coding

14


Compression using motion vector

MPEG-2 video coding


MPEG-2 GOP structure(GOP = Group Of Pictures)

Intra-coding

› I pictures

Forward prediction

› P pictures

Bidirectional prediction

› B pictures

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› Transport stream (TS) is a format specified in MPEG-2 Part 1 (ISO/IEC standard 13818-

1) which contains seven packets of 188 bytes each (184 bytes of payload and 4 bytes of

packet header)

› TS can also be utilized to transport MPEG-4 encoded video

MPEG-2 TS


The packet ID (PID) is part of that 4-byte header and represents a unique

address identifier for the type of packet or payload carried by the TS. Video

or audio packets in the stream need to have a unique PID. This allows the

decoder or STB to process the packets accordingly.

MPEG Transport Stream structureMulti-program transport stream (MPTS)

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Header (4 bytes / 32 bits) MPEG Transport Stream structure

Source: IP Television Ma


STBIP IP IP IP IP IPTS TS TS TS

IP IP IP IP IP IP

OpticalDSL

Ethernet/ATM

DSLAMAccess network

Head

End

CoreLast mile

Edge Last mile HomeTS = MPEG2 Transmission Stream

IPTV over the network

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Part 4

Ensuring Quality of Experience


All is about Quality of Experience

Quality of experience (QoE) refers to the overall IPTV user experience,

including application responsiveness, functionality, usability, and the

service context that surrounds it.

Video quality of service (V-QoS) refers to the error-free video delivery

from the operator’s facilities to the customer’s premises.

Video quality (VQ) refers to the video content itself.

Analysis and Realization of IPTV

Service Quality

Bilgehan Erman and Elissa P. Matthews

Often the QoE of a customer is only known when

he calls to complain or when subscription revenue

drops needed !

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Scope of error analysis

A/Vsource

Encoder / multiplexer

CoreNetwork

AccessNetwork

HomeNetwork

Decoder STB[1]

A/Vmonitor

Scope of the error analysis

Scope of Quality of Experience

VQ VQ

V-QoS

Video Stream QoE = (Quality of the Network Delivery System + Quality

of the Encoding Components to the Network + Quality of the Decoder

from the Network + Human Factors) per unit time[1] STB = Set Top Box

Aggregation

Network


Quality of Experience

Video content is encoded and compressed into transport streams, which

are mapped into IP packets for transport across the network. As the

packet transitions through the network it is subject to:

› Packet Loss: loss of packets

› Jitter: variation in arrival times

› Latency: delay in packet arrival due to congestion or routing

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Quality of Experience

Quality of Experience› Depending on which type of problem you have and which

frame is corrupted, you may experience different problems.

› Resulting in tiling, frozen frames or complete loss of picture

Jitter Effect Packet Loss Effect Out-of-order Effect


Packet Loss

It is the failure of one or more transmitted packets [of data] to arrive at their destination and is

typically cited as a percentage.

Loss of IP packets (ultimately those carrying MPEG information) may occur for multiple

reasons

› Network congestion (over-utilization, over-subscription, hand-offs between carriers, bandwidth

limitations)

› Higher priority traffic blocking lower priority traffic

› Network equipment problems (failed switches, routers, etc.)

› Setting / configuration problems (10/100 Mbps mismatches, use of duplicate IP addresses, etc.)

› Video equipment issues (transmission errors)

› Cabling issues (wiring issues, failed links issues)

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Depending on the type of transport protocol used for the video streaming, a packet loss will

affect the quality of the perceived video differently.

› When UDP is used, the lost packets will directly affect the image since the information cannot be

recovered and the image will be corrupt or unavailable.

› When transmission control protocol (TCP) is used, a packet loss will generate a retransmission,

which can produce a buffer underflow that may result in a frozen image.

Packet Loss


Packet Jitter

It is the variation in arrival time between packets.› A constant rate of packet arrival is preferred

› However, the IPTV system can accept a certain amount of jitter—too much jitter will

result in lost packets.

IP IP IP IP IPIP

First Last

TX RX

Arrival Time

Ideal case with constant arrival time (no jitter), no

packet loss and no error.

IP

t2 t3 t1=t2=t3t1

RFC 3550

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Impact on the quality

Too much jitter will result in lost packets.

The impact of packet loss on an IP video call depends upon a number of factors including:

› The percent of packet loss

› The distribution of the packet loss over time

› The capabilities of the endpoints / devices (STB)

Packet loss causes voice clipping and skips, often resulting in choppy and sometimes unintelligible audio.

IP IP IP IP IP

First Last

TX RX

Real case with not constant arrival time (packet jitter),

packet loss and errors.

IP

t1 t2 t3 t1≠t2≠t3


› Inside the MPEG Transport Stream, it is carried out also synchronization information.

› This clock synchronization information is called PCR

› PCR info is instantaneous value or sampling of the original 27MHz system clock (STC).

› PCR info allows the MPEG decoder to recovery the original clock.

Program Clock Reference (PCR)

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Program Clock Reference (PCR)

Video input

RX

PCR Video Audio

IP IP

27MHz STC

Video encoder DSLAM

PCR

TX

IP PCR Video Audio

Video decoder

27MHz PLL


It is the difference between measured arrival time of last bit of the PCR counter

and the expected value of the PCR. Expected arrival time is derived from the

PCR counter value inside the MPEG packets

Program Clock Reference (PCR) Jitter

ETSI TR 101 290

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Media Delivery Index (MDI) is an index of quality of service (QoS).

Measurements serving as indicators of problems in the network that can be proactively addressed before it becomes a service affecting issue

One of the key benefits - does not perform any type of stream decoding to achieve its metrics and therefore it does not require significant real-time processing power.

MDI uses packet level metrics so it can be used to validate network equipment such as switches and routers

Media Delivery Index

RFC 4445


MDI and Quality of Service

MDI is expressed as Delay Factor (DF) and Media Loss Rate (MLR)

› DF indicates how long a data stream must be buffered or delayed at its nominal

constant bit rate to prevent packet loss

› MLR is a measurement of the number of lost or out of order media packets

(transport streams) over a selected time interval.

MDI Low/Good QoE

5:0

MDI Low/Good QoE

10:0MDI High/Bad

QoE

122:8

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Broadband Core

Network Access

Network

› Set Top Box is auto-discovered by the middleware / network (DHCP) and middleware

downloads the STB client software configuration

› When customer selects a video broadcast channel, the STB launches a request

(IGMP) to connect to the appropriate IP port in the network

Home Network

Set Top

Box

Channel 208=

IP packet:

239.192.75.125

IPTV

Middleware

Head End

Customer

profile

Channel 208=

IP packet:

239.139.72.125

Set Top Box InitializationChannel Selection


Zapping time - IGMP in Action

NETWORK

FO

X

CN

N

HB

O

IGMP

CONTROL

POINT

FOX MPEG

IGMP Leave FOX

IGMP Query

IGMP Join CNN

CNN MPEG

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Impact of IGMP Delays


Performance Indicators (IPTV delivery)

Parameter Acceptable Marginal Unacceptable

MDI – Delay Factor (ms) 9 to 15

* de-jittering of STB

allows for higher DF

15 - 50 > 50

MDI – Media Loss (fps) 0 .02 to .05 > .05

Packet Jitter (ms) < 5 5 – 30 > 30

Packet Loss (%) < 0.5 0.5 to 1 > 1

PCR Jitter (ms) 0 1 - 9 > 10

Zap Time (ms) < 250 250 – 400 > 400

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Part 5

EXFO solutions by application


CUSTOMIZATION

DATA MINING

time saving

OSS integrationclose-out test

workforce automation test-head support

customer-specific tests collect results set

easy to use

OPEX

AXS-200/600

work order

job note

bluetoothtaskforce PROFILE triple play

Troubleshooting Installation Maintenance

Provisioning

IPTV service testing VoIP service testing Data service testing

Pre-qualification

The AXS-200/600 series

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REMOTE TERMINAL

CENTRAL OFFICE

DSLAM

DSLAM

Triple Play Services

xPON

Data service verification

IPTV Analysis

VoIP Analysis

AXS-650Application

Ethernet service verification

AXS-200/650 Applications

Ethernet Triple Play Testing

AXS-650

Ethernet Triple Play testing expands products capability


IPTV Service testing• MPEG2/4 TS, WM9/VC-1

• Bandwidth usage

• IGMP and STB Info

• IGMP Emulation

• Packet Loss, Jitter counter

• Graph & tabular output

• Zap Time

• QoS Pass/Fail Indicators

VoIP Service Testing• Monitors SIP, MGCP, SCCP

• Call Flow

• Codec indicator

• Packet Loss, Jitter counter

• Delay counter

• Graph & tabular output

• QoS Pass/Fail Indicators

Data Service Testing • PPPoE, PPPoA, IPoE, IPoA

• Tx / Rx counters

• PING, Traceroute

• WEB (HTTP) and FTP speed tests

• ATM Setup & Statistics

• VPI–VCI, OAM Loopback

RIGHT TOOL FOR PON (FTTH) !

Basic IP Service Verification• Errors, TX / RX counters, PPP, IP, DHCP & Static IP address


Fiber Optic Inspection Probe

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Fiber Connector Inspection

› Cleaning is one of the most neglected operations but

it is the most important one

› Remember also to clean the connector which you

connect to. This must be done at LT,NT, ONT, splitter

and ODF.


Fiber Inspection Probe

Permanent damage can occur on

dirty connectors when high power

signal is turned on !


Login

› provides PPP, IP, and bridged Ethernet encapsulation

methods and support PAP/CHAP authentication.

Ping

› user definable address, packet size and number of

attempts. Reports success or failure.

Traceroute

› user definable address, number of hops. Reports

success or failure

HTTP/FTP test

› determine access to user definable web and FTP

server address (URL or IP address)


Data

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STB Emulation

› emulates Set Top Box (STB) for joining/leaving

channels and zap time analysis

Codec Independent

› works in environments using MPEG-2, MPEG-4,

H.264, and Microsoft codecs

Metrics

› PID Viewer, PCR Jitter, Packet Loss, Packet Jitter,

Zap Time


IPTV


Media Delivery Index

› Supports RFC4445 (MDI) and displays Delay Factor

and Media Loss Rate. Can be used on conjunction

with the EXFO FTB-8510B which provides MDI

measurements in the network core

QoS Pass/Fail

› Quickly see whether the circuit passes or fails based

on user definable thresholds


IPTV

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Monitor

› Monitor VoIP calls to ensure correct Caller ID, call

flow, and codecs (G.711, G.729, G.726, G.723)

Metrics

› View Packet Loss, Jitter, and Delay distribution

graph

QoS Pass/Fail

› Quickly see whether the circuit passes or fails

based on user definable thresholds

Counters

› Duplicated or Out Of Sequence packets, Invalid

received packets


VoIP

Thanks !

ftth, access and triple-play testing urbino 2011 · ftth, access and triple-play testing ... failed...

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