P2P ??

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???????

• ????/??????
• P2P ??
• ????????????????

??? ?????????? tsaiwn_at_csie.nctu.edu.tw
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????(VoIP)??

• VoIP Voice over IP network
• IP network ????? IP ?????????
• IP Internet Protocol
• Protocol ?? ??
• ????(Internet)????? TCP/IP
• TCP/IP ????????
• ??TCP, UDP, IP, SNMP, SMTP, FTP, HTTP, ICMP,
  IGMP,

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????(IP TV)

• VOD, MOD, ..
• P2P TV ants, PPStream, PPLive,
• ??????
• MPEG2, MPEG4, H264
• ?????????
• SMIL(Synchronize Multimedia Integration Language)

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IPTV Market

• 2006 is key year major operators are expanding
  or launching service
• Market environment is very different from country
  to country
• 10 Million subscribers in Western Europe by 2009

• Subscriptions will be main source of revenue
• Differentiation is key
• Western European opportunity for IPTV
  subscriptions is almost 2.5B by 2009

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??????????

• ??ADSL????PPPoE????IP ??,?????IP ??,???????????IP
  ??Cable Modem ?????????DHCP????IP??,????????IP???
  ?
• ADSL(Asymmetric Digital Subscriber
  Line) ???????????????,????56K???????,?????????????
  ????????????????????????,?????????
• PPPoE (Point-to-Point Protocol over
  Ethernet) ?????????????Modem(?xDSL,?)????????,????
  ??????????????,??????????(ISP)?ADSL???????ADSL???,
  ????????,????????
• DHCP(Dynamic Host Configuration
  Protocol) ??????????????????? Ethernet Address
  ??, ? DHCP server ?????? IP, Netmask, Default
  Gateway, DNS ??????????????????? IP????? DHCP ???

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?? ADSL ??
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ADSL ??
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PPPoE
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ADSL ????
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??????

• VoIP(Voice over Internet Portocol)???1995?????,???
  ?????
• ??????????????(PSTN)????????????????
• ???????????????????(data packet),????????????
• ???? (???????? )
• Skype ?????, ???PSTN, PSTN ???
• IPBB ??, ????? ??????????, ?????????????????????
  ??3000? ???????????? IPBB?????

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Skype ???? (1/2)

• ?? SuperNode ??
• ?????????
• P2P(Peer-to-Peer)??
• Napster????P2P, 1999?????????????Shawn Fanning
  ??????? MP3????????????
• ??Gnutella, FastTrack/Kazza,,Kuro, ezPeer
• FastTrack?Kazaa?Scandinavians?Niklas
  Zennstrom(Skype???)?Janus Friis???,?supernode????2
  001?3?,???????Consumer Empowerment?????????
• 2005/09/12 Skype ?41??? ??EBay ????!

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Skype ???? (2/2)

• ???????? VoIP
• ???????? Skype-out, ??????????0.7?????
• ??? Skype-in ??, ????????
• ???Call forwarding
• ?? Voice Mail ????

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IPBB ????(?? Skype)
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D-Link VoIP???????DVG-1401SP

• VoIP??????????? ADSL

???ADSL ???
???
?????? ?? ipbb-out, ?????????????????
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D-Link VoIP?????????

• ???????? DVG-1401SP
• ?Browser (? MSIE)?? 192.168.15.1
• Default ??/?? user/user

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Login ? DVG-1401SP??
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WAN ??
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LAN ??
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Access control
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?????
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?? ipbb ???????
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P2P ??

• Napster????P2P, 1999?????????????Shawn Fanning
  ??????? MP3????????????(? BMG ???????)
• BMG (???)?2003/11 ? Sony ??(2004/07?????)
• Sony ?2005/04/08 ?48????? MGM (???)

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P2P file sharing

• Napster
• Centralized, sophisticated search
• Gnutella
• Flooding, TTL, unreachable nodes
• FastTrack (KaZaA)
• Heterogeneous peers
• eDonky, eMule, BitTorrent,
• Anonymity, caching, replication

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Napster

• Centralized index
• File names gt
• active holder machines
• Sophisticated search
• Easy to implement
• Ensure correct search
• Centralized index
• Lawsuits
• Denial of service
• Can use server farms

P1
P5
S
P2
P4
P2
Where is quit playing games ?
FTP
P3
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Gnutella

• Flooding
• Overlay network
• Decentralized
• Robust
• Not scalable.
• Use TTL. Query can fail
• Can not ensure correctness

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KaZaA (FastTrack) (1/2)

• Super-nodes
• Election
• capacity
• bandwidth, storage, CPU
• and availability
• connection time
• public address
• Use heterogeneity of peers
• Inherently non-scalable
• If flooding is used

P
P
P
P
P
P
P
P
P
P
P
P
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KaZaA (FastTrack) (2/2)

• Supernodes
• Kazaa Media Desktop (KMD) users with the fastest
  Internet connections and the most powerful
  computers are automatically designated as
  Supernodes.
• A Supernode contains a list of some of the files
  made available by other KMD users and where they
  are located. When you perform a search, your KMD
  first searches the nearest Supernode to you, and
  then sends you immediate results.

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eDonkey / eMule

• Started on May 13th 2002
• Based on the eDonkey2000
• new version use Kademlia serverless network
• Claims
• Most reliable peer-to-peer file sharing clients

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Classic server based eD2k

• Each client must be connected to a server to the
  network
• server checks to see first other clients can
  freely connect to your client
• Yes, assigned a High ID
• No, assigned a low ID
• After ID is assigned a list of all shared files
  is sent to the server, server as the hash values
  to the database

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BitTorrent

• Delivers a sets of large files to people
• uses the upload capacity of everyone trying to
  download the files
• As the number of people downloading the files
  goes up, uses the bandwidth of everyone
  downloading the file to deliver to everyone else
  downloading the file.

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Risks of File Sharing (1/2)

• Virus vulnerability
• do something bad to your own system
• attempt to transmit itself to other computers
• the chances of obtaining a virus increases
  because some files are modified to include a
  virus or have had their filenames changed to
  represent a desirable program
• Spy Ware (????)
• Spy ware are programs that track your network
  activity, such as web sites you've visited, data
  you have submitted on the web (your phone number,
  name, address, ...) etc., and send it to a
  company without your knowledge

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Risks of File Sharing (2/2)

• More than 12 spyware in free Kazza
• To name a few Gator, Cydoor, SaveNow and eZula
• Kazaas paid version doesnt have spyware!! ?)
• Other popular P2P freeware like iMesh, Morpheus,
  and many more all had spyware ?
• Over 70 P2P viruses by July, 2003 (from Sophos,
  PLC)
• Kazaa is targeted by 69 of the 71 viruses

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IRTF Research Groups

• Peer-to-Peer (P2P) is a way of structuring
  distributed applications such that the individual
  nodes have symmetric roles.
• Rather than being divided into clients and
  servers each with quite distinct roles (such as
  Web clients vs. Web servers), in P2P applications
  a node may act as both a client and a server.
• P2P systems are in general deployable in an
  ad-hoc fashion, without requiring centralized
  management or control. They can be highly
  autonomous, and can lend themselves to anonymity.
  
• Some historical examples of P2P systems are
  USENET servers, built on top of NNTP, and
  inter-domain routing, built on top of BGP.

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Sun JXTA project

• JXTA technology is a set of open, generalized
  peer-to-peer protocols that allows any connected
  device (cell phone to PDA, PC to server) on the
  network to communicate and collaborate.
• Java JXTA-J2SE APIs

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References

• http//www.skype.com/skype_p2pexplained.html
• Kazaa website
• gnutella website
• emule website
• bitTorrent website
• IRTF Research Groups http//www.irtf.org/charters
  /p2prg.html
• Sun JXTA project http//wwws.sun.com/software/jxt
  a/

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?? NAT ???? Worm ??
????????????????

• Network Address Translation
• ?????????
• ???????
• NT800NT3000??(2005?)
• ???

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Why????????????

• Worm
• ???Worm 1987 ?Cornel??by Moris
• ?????????
• ???? Virus ????
• Solution
• ???????(Patch)
• ?? NAT ??? private IP
• ?? private IP vs. public IP ?

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NAT

• Network Address Translation
• Private IP to Public IP translation
• Use port mapping technique
• All private addresses are translated into the
  same public address but different port numbers
  are used.
• NAT Router keeps track of these in a table and
  translates back returning traffic
• Static NAT (for servers)

Private IP ? Public IP ?
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Private network

• Private IP network is an IP network that is not
  directly connected to the Internet.
• NAT is a method that enables hosts on private
  networks to communicate with hosts on the
  Internet.
• Private IP (non-routable IP addresses)
• 10.0.0.0 10.255.255.255
• 172.16.0.0 172.31.255.255
• 192.168.0.0 192.168.255.255

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D-Link DI-740UP ?????
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???? ????

• ??? Router
• ?? ??(packet)?? IP address
• ?????????? router mode ? bridge mode (?????? IP
  address????)
• ??? Switch
• ??? IP address, ??? MAC address
• MAC address ?????????, ????????????, 48 bits
• ??? Hub --- ? MAC address ????

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DI-704UP ????
DI-704UP ????? IP ? 192.168.0.1 (????????), ????
Browser (? IE) ?? http//192.168.0.1 ?????
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??????IP (static IP)
ADSL ??????PPP over Ethernet
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WAN ?? (??????)

• WAN IP
• WAN subnet Mask
• WAN Gateway
• DNS

DNS ???????????????? ?
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????????

• WAN IP
• WAN subnet Mask
• WAN Gateway
• DNS
• Domain Name Service

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??(WAN)??
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??(LAN)??
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DHCP ?? IP ???
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??????

• ????
• ???
• tsaiwn_at_csie.nctu.edu.tw