Conducted by:Cheng Wen Chi Chiu Kwok Shing Choi 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. 3TD1a-09, BEng of Computer Engineering, HKUST

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. 4TD1a-09, BEng of Computer Engineering, HKUST

What our system look like? Tracker Video Server Client-side application 5TD1a-09, BEng of Computer Engineering, HKUST

What our system look like? TD1a-09, BEng of Computer Engineering, HKUST6

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 7TD1a-09, BEng of Computer Engineering, HKUST

P2P network management Tracker Server Channels Peers Connection Registration & Deregistration Reconnection & Loop Handling –Presented by Cheng Wen Chi 8TD1a-09, BEng of Computer Engineering, HKUST

Tracker Tracker 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 9TD1a-09, BEng of Computer Engineering, HKUST

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 10TD1a-09, BEng of Computer Engineering, HKUST

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 11TD1a-09, BEng of Computer Engineering, HKUST

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 12TD1a-09, BEng of Computer Engineering, HKUST

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 13TD1a-09, BEng of Computer Engineering, HKUST

Disconnection Causes of disconnection 1.TCP connection timeout 2.Continuous miss chunk 3.Chunk sequence no. out of range Disconnection log store in local peer list Use for peer selection of reconnection 14TD1a-09, BEng of Computer Engineering, HKUST

Deregistration 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 15TD1a-09, BEng of Computer Engineering, HKUST

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 16TD1a-09, BEng of Computer Engineering, HKUST

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 17TD1a-09, BEng of Computer Engineering, HKUST

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 18TD1a-09, BEng of Computer Engineering, HKUST

Loop Detection 2)Receive Wait 5 1)Reconnected 3)Loop detected 4)Disconnected 19TD1a-09, BEng of Computer Engineering, HKUST

Data format & hybrid algorithm Data format & encryption Sub-Streaming Push algorithm Pull algorithm –Presented by Choi Kwok Yam 20TD1a-09, BEng of Computer Engineering, HKUST

Data format Four containers of VLC streaming server 21TD1a-09, BEng of Computer Engineering, HKUST

Data Encryption Transport Stream (TS) HeaderVideo Payload 4 Bytes 184 Bytes Streaming chunk TSPLSNTS … 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 HeaderData Payload TS … HeaderVideo Payload Header 40 Bytes Each streaming chunk include 20 TS packets Data Payload size: 3942 bytes Overhead of each streaming chunk: 6% 23TD1a-09, BEng of Computer Engineering, HKUST

Sub-streaming … Single stream of chunk with Sequence number {1, 2, 3 … 10} Combine & Decompose S1S1 Three sub-streams {S 1, S 2, and S 3 } S2S2 S3S … … … 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. 24TD1a-09, BEng of Computer Engineering, HKUST 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 Parent nodeChild node Connection request 2. Connection success 3. Send latest chunk (n) 4. Send chunk (n+1) TD1a-09, BEng of Computer Engineering, HKUST

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) S1S1 S2S2 S3S … … … Miss chunks S1: 7 S3: 6,9 1. Detection 26TD1a-09, BEng of Computer Engineering, HKUST

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 chunk 3.Compare missing sequence number and video playing sequence number 4.Copy missing chunk to playback or upload buffer PlaybackUpload Request side: 2. Recovery 27TD1a-09, BEng of Computer Engineering, HKUST

Pull algorithm Peer APeer B Sequence map Chunk request Response Buffer 1.Search sequence map 2.Copy the chunk from upload buffer Response side: 28TD1a-09, BEng of Computer Engineering, HKUST

Libraries and Statistic Tools Video library and Implementation XML Database Library Statistic Tools Plug-in –Presented by Chiu Kwok Shing 29TD1a-09, BEng of Computer Engineering, HKUST

Video Library DLL library Creation to access VLC library Video broadcast function Virtual Server broadcast and Video buffer 30TD1a-09, BEng of Computer Engineering, HKUST

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, HKUST31

Video Broadcast 32TD1a-09, BEng of Computer Engineering, HKUST

Virtual Server & Video buffer Virtual Server Video Buffer 33TD1a-09, BEng of Computer Engineering, HKUST

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 34TD1a-09, BEng of Computer Engineering, HKUST

Statistic Tools Plug-in Why we develop the Statistic Tools? 35TD1a-09, BEng of Computer Engineering, HKUST

What the tool can do? Upload Speed graph Download Speed graph Upload Log Download Log 36TD1a-09, BEng of Computer Engineering, HKUST

How the tool work? P2PTV statistic application model Flow chart of the model 37TD1a-09, BEng of Computer Engineering, HKUST

Result & Findings  Playback Hit Rate  Recover Rate  Playback Overhead percentage TD1a-09, BEng of Computer Engineering, HKUST38

Results & Findings TD1a-09, BEng of Computer Engineering, HKUST39 Playback Hit Rate Sub-stream NumberPushPull 2 45% %96.86% %98.77% Test Result with1500kbps Mp4 video Playback hit rate = number of chuck played by VLC/ number of chunk received Playback Hit Rate Sub-stream NumberPushPull %99.96% %99.93% %99.84% Test Result with 360kbps Mp4 video

Results & Findings 40 Test Result with 1500kbps Mp4 video Recover rate Sub-stream NumberPull % 471% % Recover Rate = number of chunk pulled / number of chunk missed Recover Rate TD1a-09, BEng of Computer Engineering, HKUST

Results & Findings TD1a-09, BEng of Computer Engineering, HKUST41 Playback Overhead Percentage Test Result with1500kbps Mp4 video Playback overhead= (1-chunk overhead)*overhead of each chunk + chunk overhead Chunk overhead= 1- hybrid receive chunk/hybrid upload chunk Overhead of each chunk = (total size of streaming chunk - total size of video payload)/(total size of streaming chunk + size of TCP header) Playback Overhead Sub-stream NumberPushPull 26.92%6.93% 46.60%6.76% 86.59%

Thanks for your attention! 43TD1a-09, BEng of Computer Engineering, HKUST