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Challenges and Approaches in Large-Scale P2P Media Streaming W.-P. Ken Yiu, Xing Jin, and S.-H. Gary Chan Hong Kong University of Science and Technology. Director︰ 童曉儒 教授 Reporter : 第二組 秦英智 M9656016 胡美慧 M9756012 楊祖豪 M9756021 王芊儒 M9756022 - PowerPoint PPT Presentation
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Challenges and Approaches in Large-Scale P2P Media Streaming
W.-P. Ken Yiu, Xing Jin, and S.-H. Gary Chan Hong Kong University of Science and TechnologyDirector Reporter M9656016 M9756012 M9756021 M9756022 M9756024 M9756027
OutlineLocating supplying peers centralized directory hierarchical overlay structure DHT-based approachContent delivery path maintenance tree-based multicast multiple trees pull-based gossipingConclusion
ADSL
(Real-time)(Buffer)
(Video Conference)(VoD)IPTV(NetRadio)
Media Streaming
Related Solutions in Media StreamingClient-server approachIP multicastContent delivery networks (CDN)P2P
Client-serverserverchannelclients1.server 2.(delay) 3.server
IP multicast(One-to-many)
Content delivery networks (CDN)
InternetCDN
Peer-to-PeerP2P 1. 2. 3.P2P 1.clientserverserver 2.
P2P media streamingP2P networkPeerP2P network(End host)
P2P media streaming P2P networkpeerP2P media streamingroutersunicast
Two major challenges in providing P2P media streamingLocating supplying peers -- dynamic uptimeMaintaining content delivery paths -- limited and dynamic peer bandwidth
Locating supplying peers 1.Centralized directory 2.Hierarchical overlay structure
Centralized directoryppstreampplive (VOD system)network address available bandwidth ServerIP address topology
Directory server
Directory server
Hierarchical overlay structureCentralized directory Directory server ClusterLeaderClusterK~3KClustermedia residesVOD system Live streaming
Directory server server
Locating supplying peers Distributed Hash Table (DHT) based
(DHT)
keyspace keyspace partitioning overlay network
keyspace partitioning consistent hashing (k1,k2) k1k2ID
consistent hashingID
overlay networkoverlay network
kkkk
K=hash(Data) Put(key,value) Get(key)->value
(Flooding)
(DHT) Gnutella
Content delivery path maintenance
Content delivery path maintenanceTree-based MulticastMultiple treesPull-based gossiping
Tree-based Multicastdatadatadata
oStreamTemporal dependency model
MDG &MDT
It isnt fair.Its fragile and prone to severe service disruption.An interior node might not be able to offer high-bandwidth video streaming to its children because of its limited bandwidth.small group steaming aplications videoconferencingmultiparty gaming
Multiple trees
SplitStreamPastryMDCmulticast treetreetreeNode
Pastry(1/2)ip128bitRouting tableLeaf setRouting tableNeighborhood setLeaf set Neighborhood setRouting table
Pastry(2/2)
Multiple Description Coding, MDC(1/2),descriptiondescription, , description
Multiple Description Coding, MDC(2/2)
Multiple tree
Pull-based gossiping
Gossip Gossipp2p
77
3
3
Gossip
I want data d urgently!
We do not have data d L
I want data d urgently!
I have d but no enough bandwidth ... L
I want data d urgently!
We all have data d
pull-based gossip
buffer map,BM DoNet
push-based gossipBM
Peer-to-peer streaming with different coding
Peer-to-peer streaming with different coding
P2P
Conclusion In this article, we focused only on two research issues related to media streaming. Others include resilience to node/link failure, preventing free riding and providing incentive mechanism, provisioning efficient user interactivity for VoD service, and offering services to users in networks behind network address translators (NATs) and firewalls.These issues are still active research topics.
As high-bandwidth wireless access becomes available everywhere, there will be a great demand on streaming applications such as news on demand through mobile devices. The techniques used in P2P media streaming could be applied in the wireless environment. However, unlike the Internet, connections in wireless networks are even more dynamic and unstable. Efforts are needed to cope with the challenges.
-Thanks for your attention-
1.2.3.Pastry Peeer-to-Peer Lookup peer
PastryPastryChord Pastry IP 128-bit (routing table)PastryN Leaf setRouting tableNeighborhood setLeaf set N Neighborhood set N Routing table N (prefix)Leaf set Neighborhood setLeaf set Neighborhood set Routing table10233102 Pastry Peer Leaf set Neighborhood set Routing table , , , , , , , , , , , , ,
, ,description, , description , description MDC coding Group of Frame (GOP) M m Rm bit loss -