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Peer-to-Peer and Peer-to-Peer and Collective IntelligenceCollective Intelligence
A platform for collaborationA platform for collaboration
Andrew Roczniak
Collective Intelligence LabMultimedia Communications Research Lab
University of Ottawa
August 9th, 2004
AgendaAgenda
Examples of How P2P WorksExamples of How P2P Works
DefinitionsDefinitions
ApplicationsApplications
P2P Architecture BenefitsP2P Architecture Benefits
Requesting ContentRequesting Content
Server
Internet
Client
Client
Client
WWW, HTTP
Content Distribution NetworksContent Distribution Networks
Server
Internet
Server
Server
Server
Server
Client
Client
Client
Akamai, Digital Island
Content Distribution on P2PContent Distribution on P2P
Server
Internet
Peer
Peer
Peer
Peer
Peer
Peer
P2P Network
Streaming ContentStreaming Content
Server
Internet
Peer
Peer
Peer
Peer
Peer
Peer
P2P Network
Streaming Content InfrastructureStreaming Content Infrastructure
Server
Internet
Peer
Peer
Peer
Peer
Client
Client
Client
Client
Client
Client
P2P Network
I want content!
We want content too!
Distributed StorageDistributed Storage
Client
Client
Client
Client
Client
Client
Data Storage
Data Storage
Data Storage
P2P Network
I need storage space!
I have some
I have some
Summary - Which Applications?Summary - Which Applications?
Content deliveryContent delivery File sharingFile sharing Streaming (Video conference, Audio)Streaming (Video conference, Audio)
End-HostEnd-Host
InfrastructureInfrastructure
Network StorageNetwork Storage
DefinitionsDefinitions
““Peer to peer is essentially a Peer to peer is essentially a technological technological communications method wherecommunications method where all parties all parties are equalare equal. The Web is not peer-to-peer, it . The Web is not peer-to-peer, it has a server-to-client model. On the Web has a server-to-client model. On the Web P2P refers specifically to a network P2P refers specifically to a network established by a group of users sharing established by a group of users sharing the same software program, like Napsterthe same software program, like Napster.”.”
Source: Condensed Net Glossary http://www.saila.com/usage/glossary/Source: Condensed Net Glossary http://www.saila.com/usage/glossary/
DefinitionsDefinitions
““From user to user. From user to user. Peer-to-peer implies that either side Peer-to-peer implies that either side can initiate a session and has equal responsibility.can initiate a session and has equal responsibility. Peer- Peer-to-peer is a somewhat confusing term, because it has to-peer is a somewhat confusing term, because it has always been contrasted to a central system that initiates always been contrasted to a central system that initiates and controls everything. But in practice, two users on a and controls everything. But in practice, two users on a peer-to-peer system often require data from a third peer-to-peer system often require data from a third computer. For example, the infamous Napster file computer. For example, the infamous Napster file sharing service was always called a "peer-to-peer sharing service was always called a "peer-to-peer network," but its use of a central server to store the network," but its use of a central server to store the public directory made it both centralized and peer-to-public directory made it both centralized and peer-to-peer“peer“
Source: http://www.techweb.com/encyclopediaSource: http://www.techweb.com/encyclopedia
DefinitionsDefinitions
““P2P computing is the P2P computing is the sharing of computer sharing of computer resources and servicesresources and services by direct exchange by direct exchange between systemsbetween systems. These resources and . These resources and services include exchange of information, services include exchange of information, processing cycles, cache storage, and processing cycles, cache storage, and disk storage for files.”disk storage for files.”
Source: P2P Working GroupSource: P2P Working Group
DefinitionsDefinitions
““A distributed network architecture may be called a Peer-to-A distributed network architecture may be called a Peer-to-Peer network, if the participants sharePeer network, if the participants share a part of their own a part of their own hardware resources (processing power, storage hardware resources (processing power, storage capacity, network link capacity, printers). capacity, network link capacity, printers). These shared These shared resources are necessary to provide the service and resources are necessary to provide the service and content offered by the networkcontent offered by the network (e.g. file sharing or (e.g. file sharing or shared workspaces for collaboration). shared workspaces for collaboration). They are They are accessible by other peers directly, without passing accessible by other peers directly, without passing intermediary entitiesintermediary entities. The participants of such a network . The participants of such a network are thus resource (Service and content) providers as are thus resource (Service and content) providers as well as resource (Service and content) requestors well as resource (Service and content) requestors (Servent).”(Servent).”
Source: R. Schollmeier, “A Definition of Peer-to-Peer Networking for the Classification Source: R. Schollmeier, “A Definition of Peer-to-Peer Networking for the Classification of P2P Architectures and Applications”, IEEE P2P Conference, 2001of P2P Architectures and Applications”, IEEE P2P Conference, 2001
DefinitionsDefinitions
““P2P is a class of applications that takes P2P is a class of applications that takes advantage of resources e.g. storage, advantage of resources e.g. storage, cycles, content, human presence, cycles, content, human presence, available at the edges of the Internetavailable at the edges of the Internet””
Source: OpenP2P.com, Clay ShirkySource: OpenP2P.com, Clay Shirky
What P2P isWhat P2P is
A Mind SetA Mind Set A system and/or application that takes advantage of resources at the A system and/or application that takes advantage of resources at the
edge of Internet or supports direct interaction among users. edge of Internet or supports direct interaction among users. A ModelA Model
A system and/or application that does not rely on fully centralized or A system and/or application that does not rely on fully centralized or client/server approachclient/server approach
An Implementation ChoiceAn Implementation Choice Example: application layer multicastExample: application layer multicast
A property of a System or an EnvironmentA property of a System or an Environment Certain situations require a P2P solution (lack of infrastructure, Certain situations require a P2P solution (lack of infrastructure,
scalability, reliability)scalability, reliability)
From: “Peer-to-Peer Computing”, Dejan S. Milojicic et al. From: “Peer-to-Peer Computing”, Dejan S. Milojicic et al.
ApplicationsApplications
Instant MessagingInstant Messaging ICQ, MSN Messenger, Lotus SametimeICQ, MSN Messenger, Lotus Sametime
BroadcastingBroadcasting
Distributed Search EnginesDistributed Search Engines
Group CollaborationGroup Collaboration Groove NetworksGroove Networks
Distributed ComputingDistributed Computing
TelephonyTelephony SkypeSkype
P2P Architecture BenefitsP2P Architecture Benefits
Cost sharing and cost reductionCost sharing and cost reduction. . A P2P architecture can help spread costs A P2P architecture can help spread costs
over all participantsover all participants
Improved reliabilityImproved reliability No single point of failureNo single point of failure
Scalability and resource aggregationScalability and resource aggregation Peers bring resources such as bandwidth, Peers bring resources such as bandwidth,
computing power or storage spacecomputing power or storage space
P2P Architecture CharacteristicsP2P Architecture Characteristics
AutonomyAutonomy Users may be unwilling to rely on any Users may be unwilling to rely on any
centralized service provider centralized service provider
DynamismDynamism Peers can enter and leave the system freelyPeers can enter and leave the system freely
Ad-Hoc collaborationAd-Hoc collaboration Application-level collaboration between users. Application-level collaboration between users.
Peers form a group of two or more users Peers form a group of two or more users based on their current interestsbased on their current interests
CriteriaCriteria
BudgetBudget
Resource Relevance to ParticipantsResource Relevance to Participants
TrustTrust
Rate of System ChangeRate of System Change
CriticalityCriticality
M. Roussopoulos, M. Baker, D. S. H. Rosenthal, T.J. Giuli, P. Maniatis, M. Roussopoulos, M. Baker, D. S. H. Rosenthal, T.J. Giuli, P. Maniatis, J. Mogul, “2 P2P or Not 2 P2P?”, IPTPS 2004J. Mogul, “2 P2P or Not 2 P2P?”, IPTPS 2004
Decision TreeDecision Tree
!
Rate of Change!
!
!
Budget
Relevance
TrustTrust
Rate of Change
Criticality Criticality
Corporate Storage
FreeNet
Content Distribution
Flash Crowds
MP3Sharing
Low High
Low High
Low
Low
High
High
Low
Low
Low Low
High
High
HighHigh
ConclusionConclusion
The goal of this section was to explain The goal of this section was to explain what P2P iswhat P2P is
P2P is more than just sharing copyright P2P is more than just sharing copyright materialsmaterials
Questions?Questions?