Private & Confidential

PPLive—A Practical P2P Live System with Huge Amount of Users

Gale HuangP2P Software Architectgalehuang@synacast.comShanghai Synacast Media-Tech Corp.Sept. 2007

Private & Confidential

Agenda

What is PPLive? – An online video broadcasting and advertising network– An efficient P2P technique platform and test bench in the world

Common & Special characters Continuous self-adjustment procedureKey points PPLive most concerns for

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1. What is PPLive?

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What is PPLive?– An online video broadcasting and advertising network

Provides an online viewing experience comparable to that of traditional TV broadcasting75 million global installed base and 20 million monthly active users600+ channels on PPLive with content ranging from news, music, sports, movies, games, live video and other interactive services to a global audience

– An efficient P2P technique platform and test bench

History of PPLive:Bill’s story

– Inventor of PPLive core technology– Dropped out of post-graduate program to start PPLive in dorm and grew the user

significantly in the first two years.

Introduction of PPLive

Estimated global installed base 75 million

Monthly active users* 20 million

Daily active users 3.5 million

Peak concurrent users 2.2 million

Monthly average concurrent users 1.5 million

Weekly average usage time 11 hours

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Industry Trends

Napster

BitTorrent

Skype

PPLive

File Sharing

Downloading

Video Streaming

VOIP

2001 2003 2004 2005

Basic Applications

Advanced Applications

PPLive is well positioned to exploit the next explosive growthPPLive is well positioned to exploit the next explosive growth

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Introduction of PPLive ——Focus on P2P Streaming

Encoding & Decoding

MPEG-4 H.264

Digital Rights

DRMDigital Watermark

Napster/ KazzaeMule/ Poco

P2P file share

Bit Torrent/ ThunderDudu Accelerate

P2P DownloadAccelerator

PPLive

P2P Streaming

SkypeHeadcall

P2P-Voip

xPlus/ ZCom/Poco MagBox

P2P-Magzine

P2P technology

Streaming technology

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Introduction of PPLive——distribution view

PPLive is a P2P Live System

– Media Publish System– P2P content delivery network– End users’ PPLive player– Multi-media formats Supported– DRM Supported

Movie

Entertainment

Online Show

Sports

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Common and Different Characters

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Common points– what topology of p2p architecture to be chosen

Tree based (multi-tree based)Mesh basedUnstructuredOther DHT based…

– How to organize peer nodes?– How to make peer nodes know and communicate with each other

?Find the partnersMake use of the partners

– How to manage the resource?– Most concern about the metric of the P2P System

Common characters

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Different points

Most different points– Viewing experiences is the most important metric

– Much more practical– Feedback from the PPLive test bench itself

75m end usersConsider their viewing experienceTake responsibility of all usersPart of users have updated version which is under control , before spreading to all of users

Ideas

Theory

PPLive test bench Feedback

Improvement

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Feedback network—— Test network Feedback ( Global)

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PPLive software Architecture

PPLive has centralized servers taking charge of registering, providing the source and bridging with other applicationsDHT based Super Node consists of stable SN and virtual SNEach SN takes charge some Channels in Live system ; while in VOD system, each SN takes charge of a certain areaIn each P2P group , we can assign a special p2p algorithm different with other groups

Overlay NetworkSN

Server

SN SNSN

SN

SSN

C

VSN

C

C

C

C

SNCandaditeResourse ListSNListPeerList

SN

SNListPeerList

Acess Server

Adapter ServerSource ServerClassical C/S or P2P

Network

One Channel, One P2P Group

One P2P Group, One P2P Strategy

Smart routing Algorithm

Global Distribution

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Peer node architecture

Peer node– Key point of the whole P2P System– Implementer of the smart routing

algorithm– Hierarchical design– A unified interface provided to the high

level applications

Disk Driver

File Management

IP

TCP/UDP/Control

Route Management

P2P

Data Transmission

Resource Management

Media Service Storage Service

Live Streaming VOD File Sharing File Storage

PPLive Peer node architecture

Net

P2P

APP

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PPLive Software Architecture

SN SN

SN

SN

C

CC

C

C

C

C

C

C

C

Public Network

server

Peer

Peer

PeerPeer

Peer

Peer

Peer

Peer

Peer

Peer

Peer

Peer

Peer

Peer

Peer

PeerPeer

Peer

Peer

Peer

Peer

Peer

PeerPeer

Peer

Peer

Peer

Network layer view

P2P layer view Global view

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PPLive Common Overlay

A Common overlay network contains

– Query queue(P2P orders)Application related

– Real streaming– VOD– File sharing

– Download from the query queue (How to execute the orders)

Application independentAbility of uploading and downloading

Query Queue

R1

R2

R3

R4

R5

R6

...

Ping-pong layer

PP1 **

PP2 ****

PP3 ***

PP4*

...

R4 R7 R10 ...

R1 R3 R6 ...

R2 R5 R8 ...

R9 R16 ...

R1：QueryQueuePP1*：pingpong

layer（*represents capacity）

Disk Driver

File Management

IP

TCP/UDP/Control

Route Management

P2P

Data Transmission

Resource Management

Media Service Storage Service

Live Streaming VOD File Sharing File Storage

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Continuous self-adjustment procedure

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1st Misunderstanding– For most P2P System, it is

commonly thought: The more users look simultaneously the better view experience the users will have.

Conclusion– For most p2p system,

especially for streaming applications (bandwidth wasted and real time requested application ), it is not necessarily the truth.

– User scale greatly influences the architecture;

Continuous self-adjustment

2200

1800

1100

650

450

250150

70

0

500

1000

1500

2000

2500

Jun 2005 Dec2005

Mar 2006 Jun 2006 Sep2006

Dec2006

Mar 2007 Jun 2007

Unit: Thousands

Nov. 2004 May 2005 Dec. 2006

• Distributed Index

Server supported

•Initial PPLive core with Single Global Index

• Chord based DHT is used for all Index Servers

Oct. 2006

• Gossip based Peer communication mingled with DHT

• Smart SN introduced to corporate with peers

May. 2007

• Unified p2p platform proposed to support multi-applications

Jun. 2007

Private & Confidential2nd Misunderstanding– Theoretical model can lead to the real performance evaluation

Conclusion– Modeling the system has a big help to design and optimize the P2P application – P2P System’s capacity can just be proved by the fact of real operation

• 1 PC server• 10Mb distribution bandwidth• 500kbps video• 250,000 audiences• 50,000 audiences from abroad

Source: PPLive database

Over 250K peak simultaneous users to watch the “Super Girl” Live, China, Q3， 2005

• 1 PC server• 10Mb distribution bandwidth• 400kbps video• 1,480,000 audiences

Source: PPLive database

A NBA play-off game with Huston Rocket, Live, China, Q2,2007

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3rd Misunderstanding– Experimental environment can represent the real network

environment.

Conclusion– PPLive was also born from the CERNET, which is specially for educational

use and very idealistic for P2P experiment– PPLive encountered many difficulties while walking out from CERNET

Heterogeneous networkUnpredictable user patternAsymmetric networkPoor network condition, half of them are 512kbps bandwidth, while we run 400kbps video on it

– Stronger and smarter algorithm should be used

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Key points PPLive most concerns for

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PPLive Platform Strategy

Broadband Network Infrastructure

Content Provider Advertiser Services Provider End Users

VOD System File SharingLive System Others…Distributed

Storage

P2P Content Deliver Network

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Continuous self-adjustment (cont)

Deeply improve the users’ viewing experience– Based on the P2P streaming technology– Adapting for Chinese complicated network environment

Integrate the multi high level applications into this platformOpen the part of the platform interface to public

– Let others join in this platform

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Thank you!

Question Time

PPLive—P2P changes our lives