quality of experience in iptv

Quality of Experience in IPTV&IPv6 Networks

A Perspective on Quality of Experience and Quality of

Service in IPTV

Maya [email protected]

IPTV QoE

Agenda

Why IPTV?

Triple play services driving the need for IPv6

Defining Quality of Experience

The importance of Channel Zapping Time

Measuring Video Quality

Testing IPTV Networks

IPTV QoE

Why IPTV?

Unlimited Possibilities! Cost Multicast replacing broadcast REAL VoD Ability to search the web for a movie Triple Play combining Voice, Video and Data Interactive communication with the audience Interactive communication between consumers using IM PVR (Personal Video Recorder) accessible from

anywhere

IPTV QoE

SMS: Hey Guys, Wanna catch a movie?Do Not Disturb Urgent: Hey Guys, wanna catch a movie?

IPTV QoE

Agenda

Why IPTV?






IPTV QoE


More devices and services are becoming IP-aware. Consequently driving the need for increased network addressing and for plug and play networking.

IP TV

Interactive Gaming &Video on demand

IP Phones

IPv6 provides the logical answer:

Expanded addressing

Automatic configuration

Improved security

Enhanced mobility support

IPTV QoE

Triple-Play Devices are Evolving to IPv6Slowly B-RAS and Service/Edge Routers

e.g., Huawei Quidway 16E; Fujitsu GeoStream R900;Juniper Junos 5.1; Laurel Networks ShadeTree v3.1

FTTH/FTTN access devices

e.g., Passave GE-PON PAS5001-N OLT and PAS6201 ONU

Application-aware firewalls

e.g., Check Point; Cisco PIX 7.0; Netscreen ScreenOS 5.0 First test at Moonv6 (UNH IOL, Nov 2004): Only one test

vendor (Agilent); very few firewalls, even fewer with VoIPv6 Today, more security devices claim to be ready for IPv6

VoD RTSP servers

e.g., Apple Darwin open source server port code to IPv6

IPTV QoE

IPTV Delivery Infrastructure

CoreNetwork

CustomerPhysical

AggregationAggregation

NetworkAccessServer

B-RASDSLAM

Edge Router

Ethernet or ATM Switches

MetroNetwork

Edge Router

Edge Router &Transport

Core Router &Transport

xDSL Modem

PPP session termination and multicast replication

or

DHCP server

IGMP Snooping/Proxyingand multicast replication

IGMP messages

IPTV QoE

IPTV and VoD are Driving Network Evolution

Video transport creates new challenges for traditional telecom networks

Routers

B-RASSwitchesDSLAM

Ethernet or ATM Aggregation Network IP/MPLSCore

IPTV or VoD source

Firewall or ALG

Robust RTSP servers

Reliability, SecurityMore important than ever

High AvailabilityCritical for video

Dominant multicast trafficrequires router

upgrades

SubscriberAuthentication

High-bandwidth access and core

IGMP snooping enables efficient use of bandwidth

Efficient bandwidth management

QoS-enabled networks

IPTV QoE

IPv6 Service Validation Challenges

IPv4Access Network

IPv4/6Dual-stack Core

BTV Head-End

AAAServers

Stored Content (e.g.Web, VoD)

Enterprise

IPv6 enabled Multi-service Edge

Soft Switch trunk Gateway

InternetB-RAS

PSTN Gateway

IP Edge Node

Video Edge

CPE

IPv6 enabledDSLAM

IPv6/IPv4Consumer/EnterpriseServices

IPv6Access Network

Firewall

IPTV QoE

IPv6 Infrastructure Validation Challenges

IPv4Access Network

IPv4/6Dual-stack Core

BTV Head-End

AAAServers

Stored Content (e.g.Web, VoD)

Enterprise

IPv6 enabled Multi-service Edge

Soft Switch trunk Gateway

InternetB-RAS

PSTN Gateway

IP Edge Node

Video Edge

CPE

IPv6 enabledDSLAM

IPv6/IPv4Consumer/EnterpriseServices

IPv6Access Network

FirewallAccess network

performance

Graceful Restart and MPLS Fast ReRoute mechanisms to ensure

rapid recovery of services

QoS for mixed IPv4 and IPv6 traffic

Routing reconvergence speed for 99.999% availability of

triple-play services

Scalability tens of thousands of

subscribers

Interoperability with legacy IPv4 devices to

ensure coexistence

IPTV QoE

Agenda

Why IPTV?






IPTV QoE

Quality of Experience (QoE) and IPTV Service

QoE describes how well a service satisfies user expectations A rating of service performance from the user perspective

IPTV QoE QoE is critical for IPTV Service User Expectation: Equal or better than todays TV services

(cable or satellite) IPTV QoE is influenced by many factors needed by customers.

Ignore any factor and the service will fail. Improving IPTV QoE requires a comprehensive

understanding of IPTV service delivery and tight maintenance of the supporting network.

IPTV QoE

Dimensions of IPTV QoE IPTV QoE is influenced by both technical and commercial factors

Other Traffic (voice, data)

Network Infrastructure

Securityand

Reliability

Technical Factors

Channel Zapping Delay

Video and Audio (Media) Qualityincluding compatibility of TP Scalability: (Performance under load)

Capacity: (Number of subscribers)

Reasonable price

Good contentUsability

IPTV QoE

Agenda

Why IPTV?






IPTV QoE

How to measure channel zapping?Events to timestamp: IGMP events (join, leave), stop receiving channel 1 (Group 1, or G1) packets, first channel 2 (Group 2, or G2) packet received, first PAT

Join G2

Stops receiving G1

Leave G1

Start receiving G2.

Leave latency

Join latency

Channel zapping latency

leave/join delay(STB-dependent)

First MPEG PAT

PAT - Program Association Table (lists the PIDs of tables describing each program).

IPTV QoE

Zapping AnalysisWhat are the critical components to measure?

Channel 1 Channel 2 Channel 3

Channel Overlap Channel Gap

Time (t)

Bit rate(bps)

Overall Zap time

Join failures

Leave failures

Channel overlap or Gap

IPTV QoE

Agenda

Why IPTV?






IPTV QoE

MPEG Video EncodingHow does it work?

Intra coded frames (I) -- which are coded as single frames as in JPEG, without reference to any other frames. Predictive coded frames (P) -- which are coded as the difference from a motion compensated prediction frame, generated from an earlier I or P frame in the GOP. Bi-directional coded frames (B) -- which are coded as the difference from a bi-directionally interpolated frame, generated from earlier and later I or P frames in the sequence (with motion compensation).

IPTV QoE

Loss of a single IP Packet (7 MPEG packets)

Packet-loss impact 3.75 Mbps stream: B packet loss vs. I packet loss

Single B-frame IP packet loss Single I-frame IP packet loss

Source: DSL Forum

IPTV QoE

IPTV Media Quality Metrics

Perceived quality of IPTV is sensitive to network impairments

Network Impairments can cause video/audio quality problems Packet loss, latency, jitter, bit errors

and out-of-sequence packets Video Impairments: blocking, blurring, edge

distortion, judder, visual noise Audio Quality and media synchronization

(lip-sync)

Noisy audio

Video & audio (media) quality

Impaired Video (Tiling)

IPTV QoE

MDI Delay Factor and Media Loss RateUse to measure transport QoS

Packet loss in SUT resultsin larger MDI loss rate

generated video

received video

Jitter in SUT resultsin large MDI delay factor

MDI is expressed as a Delay Factor (in msec) and a Media Loss Rate (packets/sec)

DF:MLR e.g. 4.22 : 1

Defined in IETF RFC4445, and endorsed by the IP Video Quality Alliance (IPVQA)

IPTV QoE

Agenda

Why IPTV?






IPTV QoE

Testing IPTV Network in the Lab Today

Using real STBs and video sources is problematic: expensive

difficult to control and run tests

space-consuming

unreliable (set-tops overheat, need rebooting, etc)

Wall of 100s of Set-top Boxes

IP NetworkInfrastructure

100s of IPTV Channels

Real video sources (servers and encoders)

IPTV QoE

Testing IPTV with Agilent N2X

100s 1000s of IPTV Subscribers

IP NetworkInfrastructure

100s of IPTV Channels

Video Source EmulationIPTV Subscriber Emulation

Replace an expensive & complex test bed with an industrial strength test solution

SubscribersVideo Sources

IPTV QoE

Conclusion

Triple play devices are evolving to IPv6 slowly

IPv6 adds significant complexity in delivering triple-play services

Maintaining IPTV Quality of Experience is crucial for IPTVs success

Key challenges are scalability, Quality of Experience, reliability and interoperability

Testing accelerates development and deployment of IPv6 services and infrastructure

Agilent is speeding readiness for IPv6 through participation at Moonv6 test events and its industry leadership

IPTV QoE

Questions?

AgendaWhy IPTV?AgendaTriple play services driving the need for IPv6Triple-Play Devices are Evolving to IPv6 SlowlyIPTV Delivery InfrastructureIPTV and VoD are Driving Network Evolution Video transport creates new challenges for traditional telecom networks IPv6 Service Validation ChallengesIPv6 Infrastructure Validation ChallengesAgendaQuality of Experience (QoE) and IPTV ServiceDimensions of IPTV QoE IPTV QoE is influenced by both technical and commercial factors AgendaHow to measure channel zapping?Zapping AnalysisWhat are the critical components to measure?AgendaMPEG Video EncodingLoss of a single IP Packet (7 MPEG packets)IPTV Media Quality MetricsMDI Delay Factor and Media Loss RateUse to measure transport QoS AgendaTesting IPTV Network in the Lab TodayTesting IPTV with Agilent N2XConclusionQuestions?

quality of experience in iptv

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