IPTV Deployment:

IPTV Deployment:Trigger for advanced network services!

T. Wauters, K. Vlaeminck, W. Van de Meerssche,S. Van den Berghe, F. De Turck, B. Dhoedt,

P. Demeester, E. Six, T. Van Caenegem

Overview

• Introduction– advanced access network services– IPTV

• Access network architecture– network transformation– network processing power

• Time-shifted television– concept– caching algorithms– RTSP proxy

• Conclusions

Overview




• Conclusions

Introduction

• Service network requirements– content delivery (IPTV, VoD)

• high bandwidth, low jitter– multiplayer games (server based, P2P)

• low delay– distributed storage

• low delay, high availability– conferencing (IP telephony, video conferencing)

• low delay and jitter– home management (automation, security)

• high availability

Introduction

• High priority: IPTV services– today: broadcast TV (live) or VoD (older content)

• highly loaded VoD servers at the network edge• complete files are stored

– solution: time-shifted TV for (very) recent content• distributed servers in the access network, storing fragments

Broadcast TV

broadcastserver

Start of livebroadcast

t1h 1 day

Time-shiftedTV

access server

1 week

Video onDemand

regional server

Video onDemand

central server

# requests

Overview


• Access network architecture– network evolution– network processing power


• Conclusions

Internet

ATM switch

aggregation network

CPN

BASDSLAM

telephone

telephone

ADSLmodem

ISP1Edge router

ISP2

Access network architecture: current

– Access Network per Service– Broadband Internet (DSL / ATM based)

• PPP terminated in single device (BAS)• Single device per subscriber

– NAT breaks E2E connectivity• PPP setup hampers autoconfiguration• PPP conflicts with application-based QoS

and multicast support

PSTN

IP aware

IP aware

PPP

switch

CPN

IP telephone

Service enablers (e.g. firewall,

caches)

Internet

ATM switch

aggregation network

CPN

NAPedge router

BASDSLAM

telephone

telephone

ADSLmodem

gateway

ISP1Edge router

ISP2

IP DSLAM

IP awareness

New services

IP aware

IP aware

Access network architecture: evolution– Converged access network– IP awareness

• Multicast support• Local P2P traffic

– Multi edge• Scalability• High availability

– New services (triple play)– Application based QoS

Access network architecture: evolutionCurrent ATM-based

broadband aggregationATM DSLAMs• Unintelligent Layer 1 aggregation• Low-speed ATM uplinks• Mostly Central Office - based

Complex, fixed connections• PPP-based• Bound to DSL CPE in the home• Provisioning cost high

Centralized B-RAS

Lack of network resiliency

• Optimized for best-effort internet• Lack of scalable routing and QoS• Typical OC-12 handoff to IP core

• Outages tolerated• Minimal financial repercussions

Next-generation Ethernet/IP-based broadband aggregation

IP DSLAMs• Intelligent aggregation with multicast support• Gigabit Ethernet Uplinks• Increasingly RT-based

Simple, flexible connections• DHCP-based• Independent of device• User-based• Provisioning cost low

Distributed routers

Highly available network

• Optimized for QoS-sensitive services• Highly scalable• 10 GbE handoff to IP/MPLS core

• Little to no tolerance of service interruptions• Risk of churn if reliability metrics aren’t met

• Increasing need for powerful and flexiblenetwork systems– today: fixed-function ASICs or low-performance

general purpose processors

Access network: processing power

• Long time to market• High cost• Inflexible: little reuse

• Low performance• Power requirements

Con

• Very fast• Highly scalable

• Programmability: flexible• Component reuse• Relatively low cost (RISC)

Pro

ASIC – based solutions(Custom silicon)

GPP – based solutions(General Purpose Processor)

– next generation: network processors (NPU)• A special-purpose, programmable hardware device that

combines the low cost and flexibility of a RISC processor withthe speed and scalability of custom silicon

Access network: processing power

Per

form

ance

/ W

att

Flexibility

General Purpose

Processor

Custom Silicon(ASIC)

Network Processor

Overview




• Conclusions

Time-shifted TV

User 1: real-time

User 2: delayed t1

User 3: delayed t2

2

3

1

core network

regional network

access network

CS: central serverER: edge routerAR: access routerAM: access multiplexer

CS ER

AR

AM

• Network view– caching of fragments– p2p caches

Time-shifted TV

• Streaming diagram

t_program

storage

t_storage

t_pause

t0 t1 tw t2 t_viewing

User 1 User 2 User 3

Time-shifted TV

• Caching algorithm– small part S for learning (< 1 GB)– large part L for storage of popular/distant fragments

programstored

locally?

request for program p

windowappropriate?

- stream fromother cache- adapt An,p

- stream locally- set to “occupied”- adapt An,p

- stream fromother cache

- stream fromserver- cache in S

is itnew?

no

no no yesyes

yes

Time-shifted TV

ER AR AM• Input parameters– 5 tsTV channels– 6 programs per channel– 45 minutes per program

• Deployment options– hierarchical caching

• caches at AR and AM level

– co-operative caching• co-operating caches at AM level

Time-shifted TV

0

20

40

60

80

100

0 1 2 3 4cache size [GB]

% re

ques

ts ER -> ARAR -> AMAM -> AR

0

20

40

60

80

100


% re

ques


• Hierarchical caching

AM caches only AR and AM caches

Server load reduced by 50% to 70% with 0.5GB caches

ER AR AM

Time-shifted TV

• Co-operative cachingAM caches only

Server load reduced by 95% with 6 co-operating 0.5GB caches

0

20

40

60

80

100


% re

ques


ER AR AM

Time-shifted TV

• RTSP proxy– implementation using RTP / RTCP / RTSP

CacheVerdict

Manager

StreamTracker

RTSPProxy Streamer

Packet Handler

ProgramGuideCacher

CacheState

Manager

CSE RTSP RTP EPG

Time-shifted TV

• RTSP proxy– measurements

• AMD AthlonTM 64 (512MB RAM)• delay between PLAY request and first RTP packet in a

server - proxy - client configuration

05

10152025303540

content notcached at

proxy

contentcached at

proxy

server only(proxy

disabled)

dela

y [m

s]

m in delayav delaymax delay

Overview




• Conclusions

Conclusions

• Access network transformation– from ATM based broadband aggregation to multi-

service IP-aware access networks

• IPTV– identified as highest-priority, bandwidth intensive

residential telecom service– server load and access network load reduced

effectively through time-shifted TV using distributedproxy streamers

Technology

IPTV Deployment: