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

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 broadcast server Time-shifted TV access server Video on Demand regional server Video on Demand central server # requests Start of live broadcast 1h 1 day 1 week t

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 IP aware IP aware PSTN PPP 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

Access network architecture: evolution ADSL modem telephone CPN DSLAM aggregation network ATM switch New services BAS ISP1 Edge router ISP2 IP awareness Internet IP aware NAP edge router Converged access network IP awareness Multicast support Local P2P traffic Multi edge Scalability High availability New services (triple play) Application based QoS IP telephone switch telephone gateway CPN IP DSLAM IP aware Service enablers (e.g. firewall, caches)

Access network architecture: evolution Current ATM-based broadband 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 Optimized for best-effort internet Lack of scalable routing and QoS Typical OC-12 handoff to IP core Lack of network resiliency Outages tolerated Minimal financial repercussions Next-generation Ethernet/IPbased 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 Optimized for QoS-sensitive services Highly scalable 10 GbE handoff to IP/MPLS core Highly available network Little to no tolerance of service interruptions Risk of churn if reliability metrics aren t met

Access network: processing power Increasing need for powerful and flexible network systems today: fixed-function ASICs or low-performance general purpose processors Pro Con GPP based solutions (General Purpose Processor) Programmability: flexible Component reuse Relatively low cost (RISC) Low performance Power requirements ASIC based solutions (Custom silicon) Very fast Highly scalable Long time to market High cost Inflexible: little reuse

Access network: processing power next generation: network processors (NPU) A special-purpose, programmable hardware device that combines the low cost and flexibility of a RISC processor with the speed and scalability of custom silicon Performance / Watt Custom Silicon (ASIC) Network Processor General Purpose Processor Flexibility

Time-shifted TV Network view caching of fragments p2p caches access network 1 core network regional network AR 2 3 AM CS ER User 1: real-time CS: central server ER: edge router AR: access router AM: access multiplexer User 2: delayed t 1 User 3: delayed t 2

Streaming diagram Time-shifted TV t_program User 1 User 2 User 3 t_pause storage t 0 t 1 t w t 2 t_viewing t_storage

Time-shifted TV Caching algorithm small part S for learning (< 1 GB) large part L for storage of popular/distant fragments request for program p no program stored locally? yes is it new? window appropriate? no yes no yes - stream from - stream from - stream from - stream locally other cache server other cache -set to occupied - adapt A n,p - cache in S - adapt A n,p

Time-shifted TV 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 ER AR AM

Time-shifted TV ER AR AM Hierarchical caching AM caches only AR and AM caches 100 100 80 80 % requests 60 40 ER -> AR AR -> AM AM -> AR % requests 60 40 ER -> AR AR -> AM AM -> AR 20 20 0 0 0 1 2 3 4 0 1 2 3 4 cache size [GB] cache size [GB] Server load reduced by 50% to 70% with 0.5GB caches

Time-shifted TV ER AR AM Co-operative caching AM caches only 100 80 % requests 60 40 20 ER -> AR AR -> AM AM -> AR 0 0 1 2 3 4 cache size [GB] Server load reduced by 95% with 6 co-operating 0.5GB caches

RTSP proxy Time-shifted TV implementation using RTP / RTCP / RTSP Cache Verdict Manager Stream Tracker Cache State Manager RTSP Proxy Streamer Cacher Program Guide Packet Handler CSE RTSP RTP EPG

RTSP proxy measurements Time-shifted TV AMD Athlon TM 64 (512MB RAM) delay between PLAY request and first RTP packet in a server - proxy - client configuration delay [ms] 40 35 30 25 20 15 10 5 0 content not cached at proxy content cached at proxy min delay av delay max delay server only (proxy disabled)

Conclusions Access network transformation from ATM based broadband aggregation to multiservice 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 distributed proxy streamers