Presentation on theme: "ECOM6001 – Internet and the WWW Peer-to-Peer (P2P) Technologies Roger Clarke, Xamax Consultancy, Canberra Visiting Professor, CSIS, Uni of Hong Kong."— Presentation transcript:
1ECOM6001 – Internet and the WWW Peer-to-Peer (P2P) Technologies Roger Clarke, Xamax Consultancy, Canberra Visiting Professor, CSIS, Uni of Hong Kong Hong Kong, October 2008
2Peer-to-Peer (P2P) Technologies Agenda Conventional Network Topologies, ArchitecturesStar Topology / Master-Slave ArchitectureClient-Server ArchitectureKey Developments since the Mid-1990sWorkstations • NetworkingHow and Why P2P is UnconventionalRelative Equality of Nodes • Node-IDsWhy P2P is AttractiveTechnical Concerns about P2P
8Key Developments Since the Mid-1990s Workstation Capacity (now rivals Hosts)Workstation Diversity (vast, expanding) desktops, laptops, handhelds, smartcards, ... phones, PDAs, cameras, ... carburettors, fridges, RFID tags, ...Broadband Connectivity (now widespread) This enables dispersion and replication of devices capable of providing servicesWireless Connectivity (rapidly increasing) This enables Mobility which means Devices change networks which means their IP-addresses change
9Wireless Comms Using Electromagnetic Radiation Wide Area Networks – Satellite (Geosynch, Low)GS is Large footprint, very high latency (c. 2 secs)Wide Area Networks – Cellular (to 20km per cell)1 – Analogue Cellular, e.g. AMPS, TACS2 – Digital Cellular, e.g. GSM, CDMA3 – ‘3G’, e.g. GSM/GPRS and W-CDMAWide Area Networks – ‘WiMax’, IEEE ; iBurstLocal Area Networks – ‘WiFi’ ( m radius)e.g. IEEE x esp. 11b,g / Apple AirportPersonal Area Networks (1-10 metre distance)e.g. Bluetooth (or beamed infra-red)Contactless Cards / RFID Tags / NFC (1-10 cm)
11P2P – The MotivationTake advantage of resources that are available at the edges of the InternetIn order to do so, make each participating program both a Client and a Server and hence each workstation acts as a host as well, e.g.a music playstation can be a mixer tooyour PDA can host part of a music catalogueyour PC can host part of a music repository
12P2P Architecture Cooperative Use of Resources at the Edge
13A Virtual Topology The P2P ‘Overlay Network’ PowerfulWork-andPlay-Workstations
15P2P – Towards a Technical Definition P2P is a network architecture in which each node is capable of performing each of the functions necessary to support the network and in practice many nodes do perform many of the functions
17Server-Functions of a P2P Package Manage Comms with other devicesManage Directories:of Objects (e.g. files)of Services (e.g. currency conversion, or credit-card payment processes)Manage Repositories of ObjectsManage Services
18Important Characteristics of P2P Collaboration is inherentClients can find ServersEnough Devices with Enough Resources act as Servers for discovery, and as Servers for services‘Single Points-of-Failure’ / Bottlenecks / Chokepoints are avoided by means of networking dynamics'Free-Riding' / 'Over-Grazing' of the 'Commons' is restrained through software and psych. features
19Some Characteristics of P2P Nodes A P2P node may be a device, a process, content, a person, or an identity of a personA P2P node’s availability may be unreliable or unstable (dial-up or mobile)A P2P node’s IP-Address may change (dial-up, or moving between subnets)So P2P apps commonly:build and re-build a virtual ‘overlay network’use their own addressing schemes, not the DNS
20Alternatives to the DNS An application-specific name-based directory (ICQ since 1996, and Groove, Napster, NetMeeting)An application-specific directory of IP-addresses without names, dynamically managed in real-time (Gnutella, Freenet)Authentication of names, and use of whatever IP-Address is advised each time they register PopularPower)A flexible, real-time DNS...
21The Scale of the Undertaking The DNS grew to c. 30 million names in 18 years from its establishment in 1984 to 2002Napster achieved that many in 2 yearsThe top 3 distributed-catalogue services combined quickly exceeded Napster at its peakAOL Instant Messaging is also very largeThe total of all P2P names may exceed 10 times the number in the DNS
22Categories of P2P Pure Compromised / ‘Two-Tier’ Hybrid Functions, objects and the catalogue are distributed across all nodes. No one node is critical to the network's operation. Control is very difficult – USENET, Fidonet, Freenet, Gnutella-1Compromised / ‘Two-Tier’Functions and objects are highly, not fully distributedThe index is highly, not fully distributed – FastTrack, Gnutella-2HybridFunctions and objects are fully or highly distributedThe index is not, e.g. it may be hierarchical (the DNS), centralised (Napster), or independent from the repository (BitTorrent)
23Why P2P Is AttractiveMuch-Reduced Dependence on individual devices and sub-networks (no central servers)Robustness not Fragility (no single point-of-failure)Resilience / Quick Recovery (inbuilt redundancy)Resistance to Denial of Service (D)DOS Attacks (no central servers)Much-Improved Scalability (proportionality)Improved Servicing of Highly-Peaked Demand (more devices on the demand-side implies there are also more server-resources)
24Technical Concerns about P2P Address Volatility: old addresses may not work (hence trust based on repetitive dealings is difficult)Absence of Central Control (hence risk of anarchy)Inadequate Server Participation (over-grazing)Security Challenges:Malware, embedded or infiltratedSurreptitious Enlistment (at least potential)Vulnerability to MasqueradeVulnerability to Pollution Attacks (decoys)
25P2P Applications – Access to Digital Objects Software:Fixes/PatchesReleasesVirus SignaturesAnnouncements, e.g. of technical info, business info, entertainment ‘info’, sports results, promotional messages, advertisementsNews Reports, by news organisations, and by members of the publicEmergency Services DataBackup and Recovery DataGames Data, e.g. scenes and battle configurationsArchived Messages, for conferencing/chat/IM, and cooperative publishingLearning Materials, in various formatsEntertainment Materials, in various formats
26P2P Networks and Protocols (2005) BitTorrent network: ABC, Azureus, BitAnarch, BitComet, BitSpirit, BitTornado, BitTorrent, BitTorrent++, BitTorrent.Net, G3 Torrent, mlMac, MLDonkey, QTorrent, SimpleBT, Shareaza, TomatoTorrent (Mac OS X) , TorrentStormeDonkey network: aMule (Linux, Mac OS X, others), eDonkey2000, eMule, LMule, MindGem, MLDonkey, mlMac, Shareaza, xMule, iMesh Light, ed2k (eDonkey 2000 protocol)FastTrack protocol: giFT, Grokster, iMesh (and its variants stripped of adware including iMesh Light), Kazaa by Sharman Networks (and its variants stripped of adware including: Kazaa Lite, K++, Diet Kaza and CleanKazaa), KCeasy, Mammoth, MLDonkey, mlMac, PoisonedFreenet network: Entropy (on its own network), Freenet, FrostGnutella network: Acquisitionx (Mac OS X), BearShare, BetBug, Cabos, CocoGnut (RISC OS) , Gnucleus Grokster, iMesh, gtk-gnutella (Unix), LimeWire (Java), MLDonkey, mlMac, Morpheus, Phex Poisoned, Swapper, Shareaza, XoloXGnutella2 network: Adagio, Caribou, Gnucleus, iMesh, MLDonkey, mlMac, Morpheus, Shareaza, TrustyFilesJoltid PeerEnabler: Altnet, Bullguard, Joltid, Kazaa, Kazaa LiteNapster network: Napigator, OpenNap, WinMXApplejuice network: Applejuice Client, Avalanche, CAKE network: BirthdayCAKE the reference implementation of CAKE,Direct Connect network: BCDC++, CZDC++, DC++, NeoModus Direct Connect, JavaDC, DCGUI-QT, HyperCast , Kad Network (using Kademila protocol): eMule, MindGem, MLDonkey, LUSerNet (using LUSerNet protocol): LUSerNet, MANOLITO/MP2P network: Blubster, Piolet, RockItNet, TVP2P type networks: CoolStreaming, Cybersky-TV, WPNP network: WinMXOther networks: Akamai, Alpine, ANts P2P, Ares Galaxy, Audiogalaxy network, Carracho, Chord, The Circle, Coral, Dexter, Diet-Agents, EarthStation 5 network, Evernet, FileTopia, GNUnet, Grapevine, Groove, Hotwire, iFolder, konspire2b, Madster/Aimster, MUTE, Napshare, OpenFT (Poisoned), P-Grid, and XDCC, used by IRC clients including: mIRC and Trillian, JXTA, Peersites , MojoNation, Mnet, Overnet network, Peercasting type networks: PeerCast, IceShare - P2P implementation of IceCast, Freecast, Scour, Scribe, Skype, Solipsis a massively multi-participant virtual world, SongSpy network, Soulseek, SPIN, SpinXpress, SquidCam , Swarmcast, WASTE, Warez P2P, Winny, AsagumoWeb, OpenExt, Tesla, soribada, fileswapping, XSCThe much-used ‘value chain’ concept appeared for the first time only in 1985.Until then, the dominant modelling form used in business had been the essentially static chart of organisational structure, or ‘organigram’.The importance of Porter’s model was to shift the emphasis from the static to the dynamic.Process was what mattered, and organisation was only a means to an end.
27P2P Multi-Protocol Applications (2005) aMule (eDonkey network) (Linux, Mac OS X, FreeBSD, NetBSD, OpenBSD, Windows and Solaris Op Env)eMule (Edonkey Network, Kad Network) (Microsoft Windows, Linux)Epicea (Epicea, BitTorrent, Edonkey Network, Overnet, FastTrack, Gnutella) (Microsoft Windows)GiFT (own OpenFT protocol, and with plugins - FastTrack, eDonkey and Gnutella)and xfactor (uses GiFT) (Mac OS X)Gnucleus (Gnutella, Gnutella2) (Microsoft Windows)Hydranode (eDonkey2000) (Microsoft Windows, Linux, Mac OS X)iMesh (Fasttrack, Edonkey Network, Gnutella, Gnutella2) (Microsoft Windows)Kazaa (FastTrack, Joltid PeerEnabler) (Microsoft Windows)Kazaa Lite (FastTrack, Joltid PeerEnabler) (Microsoft Windows)KCeasy (Gnutella, Ares, giFT)MindGem (Edonkey Network, Kademlia)MLDonkey (BitTorrent, eDonkey, FastTrack, Gnutella, Gnutella2, Kademlia) (MS Windows, Linux, Mac OS X, Palm OS, Java)mlMac (BitTorrent, eDonkey, FastTrack, Gnutella, Gnutella2)Morpheus (Gnutella, Gnutella2) (Microsoft Windows)Poisoned (FastTrack, Gnutella)Shareaza (BitTorrent, eDonkey, Gnutella, Gnutella2) (Microsoft Windows)WinMX (Napster, WPNP) (Microsoft Windows)XNap (OpenNAP, GiFT, Limewire, Overnet, ICQ, IRC) (Java)Zultrax (Gnutella, ZEPP)The much-used ‘value chain’ concept appeared for the first time only in 1985.Until then, the dominant modelling form used in business had been the essentially static chart of organisational structure, or ‘organigram’.The importance of Porter’s model was to shift the emphasis from the static to the dynamic.Process was what mattered, and organisation was only a means to an end.
28Business and Government Concerns about P2P Address Volatility, plus Inadequate Identifiers, hence:Difficulty in identifying and locating usersReduction in user accountabilityAbsence of Central Control, hence:Reduction in technology-provider accountabilityNo single point for a denial of service attackChallenge to Authority:of Copyright-Owners over Usersof Censors over Users
29Challenges for Copyright-Owners Identification of Copyright ObjectsIdentification of Devices that store those objects and that traffic in themDemonstrating: Unauthorised Reproduction, Publication, Adaptation and/or AuthorisationIdentification of the Person Responsible for a breachAssociation of the Person with the Device used to perform the act that constitutes the breachLocation of the responsible PersonBringing Suit (e.g. jurisdiction)Collection and Presentation of Evidence sufficient to win even civil, let alone criminal casesProposing Interventions that could be awarded by court injunction
30Application of P2P to eTrading in Music Identify price resistance-points in the various customer-segments i.e. ‘what the market will bear’Set prices accordingly (and hence sustain payment morality)Make backlists and new releases available via for-fee P2P channelsDiscourage and prosecute breaches where the purpose is commercialTake no action over breaches by consumers (esp. time-shifting, format-change, even sharing?)The EvidenceSince 2003, Apple iTunes charges USD 0.99/track!?Copyright-Owners get USD 0.70Since , they want moreThey want Jobs to enable variable track-pricing