conducted by:cheng wen chi chiu kwok shing choi kwok yam advised by prof. danny tsang

Conducted by: Cheng Wen ChiChiu Kwok ShingChoi Kwok Yam

Advised by Prof. Danny Tsang

TD1a-09, BEng of Computer Engineering, HKUST

Introduction

What is P2P IPTV? What is IPTV

IPTV is a system that deliver digital television content through Internet Protocol

What is P2P P2P is any distributed network architecture composed of

participants that make a portion of their resources directly available to other network participants, without the need for central coordination instances.

2TD1a-09, BEng of Computer Engineering, HKUST

Background• Motivation to start the project.

Rapidly development of network technology in Hong Kong

• (77% household broadband penetration - by OFTA)

HDTV become part of our life.Advantage of P2P model on HDTV

broadcasting.


Purpose and Aim

This project examines streaming IPTV over P2P networks with high quality(up to 1000kb/s) video in the different approaches, in order to create a low delay, high quality IPTV application, thus different P2P algorithms may be applied, such as pure push, hybrid, etc.


What our system look like?

Tracker

Video Server

Client-side application


What our system look like?

TD1a-09, BEng of Computer Engineering, HKUST 6

Presentation Flow

P2P network management• Presented by Cheng Wen Chi

Data format and hybrid algorithm• Presented by Choi Kwok Yam

Libraries and Statistic Tools• Presented by Chiu Kwok Shing

Results and Findings


P2P network management

• Tracker Server

• Channels

• Peers Connection

• Registration & Deregistration

• Reconnection & Loop Handling– Presented by Cheng Wen Chi


TrackerTracker server• Centralized database which maintain info of P2P network

– P2PTV client– Channel info. of streaming server

• Maintain the P2P network topology and connection

4 main services:• Channel registration• Peer list request• Peer registration• Peer deregistration

Child Peer

Channel Selection

Peer Selection

Peer List Information

TC

P H

andl

erTracker Server

Peer Information

TCP Handler

Channel Registration

Peer Request

Peer Deregistration

Peer Registration

Video Server

0. Channel Registration

1. Channel Request

2. Reply Channel List

4. Peer List Request

5. Reply Peer List

3.

6.

Parent Peer

7. Peer ConnectRequest 8. Reply Port

9. Connect To Server10. Register the Child

to Tracker

11. DeRegister the Child Peerif connection fail


Channels• Multiple broadcast channels• Each channel is registered by a streaming

server• Channel information include

– channel name– streaming server IP– sub stream size– video size

• Channel information is downloaded by peer when client terminal start up


Connection• Sub streaming algorithm• Individual TCP connection for each sub stream• Different thread handle each sub stream connection• For upload stream, select TCP ports which available for

remote connection• Provide TCP ports information to child peers for new

connection process– Data port– Control port


Connection Establishment

Flow of connection establishment• Download peer list of selected

channel• Select a peer from peer list

based on selection algorithm• Request a new connection with

selected peer• Peer provide a pair of TCP ports

for data and control connection


Registration

• Parent peer registers its child peers• Register to tracker individually in each tree• Information of registration

– Child peer id– Parent peer id– Sub stream id– Channel id

• connection map between peers is maintained in tracker

• Used for loop detection and optimization of P2P network


Disconnection

Causes of disconnection1. TCP connection timeout2. Continuous miss chunk3. Chunk sequence no. out of range

• Disconnection log store in local peer list• Use for peer selection of reconnection


Deregistration

Parent Monitor the Child Connection

Connection Exist

Check Child’ s Parent ID

Disconnected

Identical

Different

Deregister the child to Tracker

End

Start• Deregistered by parent peer• Deregistration message which include

– Parent peer id– Child peer id– Tree id, channel id

• Tracker verify the deregistration request by matching the parent id and child id in registration records


Recursive Deregistration

• Deregistration problem of inter peer of sub tree

• Take place when a sub tree is connected from P2P network

• Tracker recursively detect the connection status of its offspring in the sub tree

• If peer (offspring) is offline, tracker will deregister it from the sub tree


Reconnection• Root peer operate on reconnection process • Child peers within the sub tree will keep its

connection with its parent peers• New peer from local copy of peer list• Peer selection algorithm select peer based on

– Miss rate– Timeout rate


Loop Detection• Loop connection may formed after reconnection

of sub stream• Detected by periodic WAIT message• When root peer is disconnected, it generates

WAIT message with its peer ID to its child peers• Child peers forward the WAIT

message to its grandchild• Streaming loop detected

by the WAIT message ID


Loop Detection

2)Receive Wait 51)Reconnected3)Loop detected

4)Disconnected


Data format & hybrid algorithm

• Data format & encryption

• Sub-Streaming

• Push algorithm

• Pull algorithm– Presented by Choi Kwok Yam


Data format• Four containers of VLC streaming server


Data EncryptionTransport Stream (TS)

Header Video Payload

4 Bytes 184 Bytes

Streaming chunk

TSPLSN TS TS …

<Header> <Payload> 182 Bytes (Number of TS packets* 188) Bytes

SN: Sequence Number

TSPL: Total TS packet length

TS: Transport Stream packet

TCP packet Data Encryption

TCP Header Data Payload

TS…

Header Video Payload

Header

40 Bytes

<Streaming chunk>

<TS Packet>

Each streaming chunk include 20 TS packetsData Payload size: 3942 bytesOverhead of each streaming chunk: 6%


Sub-streaming

… 10965432

Single stream of chunk with Sequence number {1, 2, 3…10}

Combine & Decompose

S1

Three sub-streams {S1, S2, and S3}

S2

S3

1 4

2 5

3 6

7

8

9

10 ………

1

Sequence number represent its playback sequence in the stream

P sub-stream :q-th sub-stream contains chunks with sequence numbers = (nP + q)where n is a positive integer from zero to infinity, and q is a positive integer from 1 to P.


Peer A

Peer B

S1

S2

S3

S1

S2

S3

Peer C

S1

S2

S3

Push algorithm

• Do not exchange the sequence number of chunks• The parent node will send the latest chunk to the child node continuously.

Time Time

Parent node Child node

.

.

.

1. Connection request2. Connection success3. Send latest chunk (n)4. Send chunk (n+1)

1

2

3

4


Pull algorithm

• Implemented in the state of pushing video chunk.

• The missing chunks will not be recovered during sub-streams reconnection

• The expected sequence number = last received sequence number + total

sub-stream number. • Example (3 sub-streams)

S1

S2

S3

1 4

2 5

3 12

10

8

15

……

… Miss chunksS1: 7S3: 6,9

1. Detection


Pull algorithm

Peer A

Peer selection process

Filter

Chunk request

Response

Missing Chunk List

1. Peer selection process(e.g. peer B)2. Sequence number of missing chunk3. Compare missing sequence number and video playing sequence number4. Copy missing chunk to playback or upload buffer

PlaybackUpload

Request side:

2. Recovery


Pull algorithm

Peer A Peer B

Sequence map

Chunk request

Response

Buffer

1. Search sequence map2. Copy the chunk from upload buffer

Response side:


Libraries and Statistic Tools

• Video library and Implementation

• XML Database Library

• Statistic Tools Plug-in– Presented by Chiu Kwok Shing


Video Library

• DLL library Creation to access VLC library

• Video broadcast function

• Virtual Server broadcast and Video buffer


Video Library

• What is VLC?– a free and open source media player and

multimedia framework written by the VideoLAN project

• Advantage of VLC?– Support large number of encode/decode

format– build up network stream through TCP– Flexible

• Reason to build up DLL library.TD1a-09, BEng of Computer Engineering, HKUST 31

Video Broadcast

Layer BLayer AVLC

PlayerVLC

PlayerInternet

Server

GUI

Client

GUI

Tracker


Virtual Server & Video buffer

Virtual Server Video Buffer

Start

Waiting core player connection

Connection Success?

Load data buffer

Broadcast to player

Stop Playing?

Close Connection

Yes

No

No

Yes

Send to Virtual Server

Accumulated enough buffer ?

Yes

No

Start

Receive Data and Store in Buffer

End

Connection Closed?

Yes

No


XML Database Library

• What is XML– a file type that included a set of rules for

encoding document

• Advantage of XML database– Cross platform– Low operation cost

• Role of XML database within the system– Database to store system information


Statistic Tools Plug-in

• Why we develop the Statistic Tools?


What the tool can do?

• Upload Speed graph

• Download Speed graph

• Upload Log

• Download Log


How the tool work?

P2PTV statistic application model

Flow chart of the model

Statistic Application

Client Speed

Statistic

Graphical User Interface

Decode

TC

P H

andl

er

Client-side Application

TC

P H

andl

er

Statistic Handler

Download Stream

Upload Stream

Send Start andEnd Time Stamp

Send Start andEnd Time Stamp

DataStream

Graph Created?

Create New Graph and XML

Append data to XML file

Yes Yes

No

StartReceived

Data?Listen for

Client

No

Display data in GUI


Result & Findings

Playback Hit RateRecover RatePlayback Overhead percentage


Results & Findings


Playback Hit RateSub-stream

Number Push Pull2 45% 45%4 97.56% 96.86%8 98.45% 98.77%

Test Result with1500kbps Mp4 video

Playback hit rate = number of chuck played by VLC/ number of chunk received

PlayBack Hit Rate

95.00%

96.00%

97.00%

98.00%

99.00%

100.00%

101.00%

2 4 8

Sub-streams

Per

cen

tag

e

Push

Pull

Playback Hit RateSub-stream

Number Push Pull2 99.90% 99.96%4 99.73% 99.93%8 99.78% 99.84%

Test Result with 360kbps Mp4 video

Results & Findings

40

Test Result with 1500kbps Mp4 video

Recover rate

Sub-stream Number Pull

2 15.24%

4 71%

8 87.43%

Recover Rate = number of chunk pulled / number of chunk missed

Recover Rate

TD1a-09, BEng of Computer Engineering, HKUST

Results & Findings


Playback Overhead PercentageTest Result with1500kbps Mp4 video

Playback overhead= (1-chunk overhead)*overhead of each chunk + chunk overheadChunk overhead= 1- hybrid receive chunk/hybrid upload chunkOverhead of each chunk = (total size of streaming chunk - total size of video payload)/(total size of streaming chunk + size of TCP header)

Playback OverheadSub-stream Number Push Pull

2 6.92% 6.93%4 6.60% 6.76%8 6.59% 6.59%

Thanks for your attention!

Thanks for your attention!


conducted by:cheng wen chi chiu kwok shing choi kwok yam advised by prof. danny tsang

Documents

beng of computer engineering

p2p iptv

p2p network topology

network participants

streaming iptv

p2p networks

channel registration1

channel request2