PPL IVE : A M EASUREMENT S TUDY OF P2P IPTV S YSTEM Sergio Chacon

A BSTRACT IPTV stands for Internet Protocol Television P2P IPTV refers to the delivery of TV over IP using point-to-point techniques PPLive is one of the most popular IPTV systems for campus and residential access Hei, et al., Polytechnic University in Brooklyn, developed a PPLive crawler to carry out in-depth measurements of mesh-pull PPLive

I NTRODUCTION Widespread adoption of broadband (residencial) Application-level, P2P, mesh-pull P2P Mesh-Pull most successful so far Rapid low cost Minimal infrastructure BitTorrent Not feasible for real time No fair resource sharing Not for large-scale live streaming

A NSWER TO QUESTIONS What are the user characteristics? How much overhead and redundant traffic? What are characteristics of peer partnerships? What are fundamental requirements for successful mesh pull?

M ESH -P ULL P2P S TREAMING S YSTEMS Streaming peer node Includes streaming client and server Channel stream server Converts media to small video chunks Tracker server Provides streaming channel, peer and chunk information for each peer node Downloads video chunks from multiple peers requesting same media content

C HANNEL AND PEER DISCOVERY

P EE ’ S BUFFER MAP OF VIDEO CHUNKS

M ESH - PULL P 2 P ARCHITECTURE

S TREAMING PROCESS MESH - PULL SYSTEMS

G LOBAL VIEW OF USER BEHAVIOR Peer tracking methodology Evolution of participating users User arrivals and departures User geographic distribution

P EER TRACKING Peer registration Bootstrap Peer query

P EER REGISTRATION Peer registration Bootstrap Peer query

N UMBER OF DISCOVERED PEERS

E VOLUTION OF PARTICIPATING USERS

H OW NUMBER OF USERS EVOLVE

U SER ARRIVALS AND DEPARTURES

P EER ARRIVAL AND DEPARTURE EVOLUTION

U SER GEOGRAPHIC DISTRIBUTION

P EER PLAYBACK DELAY AND LAGS Start-up delay Video buffering Playback lags among peers

S TART - UP DELAY Time interval between channel selection and playback P2P also have to deal with startup buffering and delay 5-10 seconds from selection to player startup 5-10 seconds from player startup to play

V IDEO BUFFERING

P LAYBACK LAGS AMONG PEERS

C ONNECTION + TRAFFIC CHARACTERISTICS Isolating video traffic Video traffic redundancy Download and upload video traffic Video TCP connections

I SOLATING VIDEO TRAFFIC

V IDEO TRAFFIC REDUNDANCY

D OWNLOAD AND UPLOAD VIDEO

P ROPERTIES OF VIDEO TCP CONNECTIONS Duration of TCP connections Number of partners Dynamic of partners Locality of partners Traffic volume breakdowns Uni-directional or bi-directional traffic?

V IDEO TCP CONNECTIONS

N UMBER OF PARTNERS

D YNAMIC OF PARTNERS

T RAFFIC VOLUME BREAKDOWNS

L OCALITY OF PARTNERS

U NI - DIRECTIONAL OR BI - DIRECTIONAL ?

U NI - DIRECTIONAL OR BI - DIRECTIONAL TRAFFIC ? Traffic flows are neither tree-like nor uni- directional (mesh) Closer in character to BitTorrent Lesson learned: mesh-pull architectures are more correctly viewed as variations on BitTorrent rather than variations on tree-pull architectures such as end-system multicast

CONCLUSIONS Current Internet is capable of providing low cost with minimal dedicated infrastructure Measurements provide understanding of how to architect large-scale P2P IPTV Areas of improvement: Shorter start-up delay Higher-rate streaming Smaller peer lags Better NAT traversal