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 -