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Transcript of 4 IPTV Koert Vlaeminck - biblio.ugent.be · IPTV Deployment: Trigger for advanced network services!...

  • 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

    •Introduction–advanced access network services–IPTV

    •Access network architecture–network transformation–network processing power

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

    •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

    •Introduction–advanced access network services–IPTV

    •Access network architecture–network evolution–network processing power

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

    •Conclusions

  • 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

    IPtelephone

    Service enablers(e.g. firewall,

    caches)

    Internet

    ATM switch

    aggregationnetwork

    CPN

    NAPedge router

    BASDSLAM

    telephone

    telephone

    ADSLmodem

    gateway

    ISP1Edge router

    ISP2

    IP DSLAM

    IPawareness

    Newservices

    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: evolution

    Current ATM-basedbroadband aggregation

    ATM 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

    /Wat

    t

    Flexibility

    GeneralPurpose

    Processor

    CustomSilicon(ASIC)

    NetworkProcessor

  • Overview

    •Introduction–advanced access network services–IPTV

    •Access network architecture–network transformation–network processing power

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

    •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

    qu

    ests ER -> AR

    AR -> AM

    AM -> AR

    0

    20

    40

    60

    80

    100

    0 1 2 3 4cache size [GB]

    %re

    qu

    ests ER -> AR

    AR -> AM

    AM -> AR

    •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 caching

    AM caches only

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

    0

    20

    40

    60

    80

    100

    0 1 2 3 4cache size [GB]

    %re

    qu

    ests

    ER -> AR

    AR -> AM

    AM -> AR

    ER AR AM

  • Time-shifted TV

    •RTSP proxy–implementation using RTP / RTCP / RTSP

    CacheVerdict

    Manager

    StreamTracker

    RTSPProxy

    Streamer

    Packet Handler

    ProgramGuide

    CacherCacheState

    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

    0

    5

    10

    15

    20

    25

    30

    35

    40

    content notcached at

    proxy

    contentcached at

    proxy

    server only(proxy

    disabled)

    del

    ay[m

    s]

    m in delay

    av delay

    max delay

  • Overview

    •Introduction–advanced access network services–IPTV

    •Access network architecture–network transformation–network processing power

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

    •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