CMPT 371 Data Communications and Networking

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CMPT 371Data Communications and Networking

• Fall 2004

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Outline

• Course information
• What is network?
• A brief introduction to the Internets
• past
• present
• Summary

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Course Information

•  Instructor
• Jiangchuan (JC) LIU Room 10826, Applied Science
  Building
• E-mail jcliu_at_cs.sfu.caTel 604-291-4336 
• Office Hours TBD (Wed afternoon ?)
• E-mail is the best way to communicate with me
• TA(s)
• Zhengbing Bian ( zbian_at_cs.sfu.ca )

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Course Information

• Time Venue
• Wednesday 1730-2020pm
• RC Brown 8100
• There will be one or two breaks

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Course Information

• Textbook
• Computer Networking A Top-Down Approach
  Featuring the Internet, by Kurose and Ross
• Reference books
• Computer Networks,
• 4/e by Andrew Tanenbaum
• Data and Computer communications, 7th edition ,
  William Stallings, Prentice Hall, 2003
• And more (see Web)
• Resource
• Home page
• www.cs.sfu.ca/jcliu/cmpt371

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Course Information

• Textbook
• Computer Networking A Top-Down Approach
  Featuring the Internet, by Kurose and Ross
• Why using this book ?
• New content this is a fast-changing area
• But more important, new structure and target
• Top-down
• Featuring the Internet

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What Are the Goals Of This Course?

• Understand how Internet works
• Its philosophy
• Its protocols and mechanisms
• Learn network programming
• Have fun!
• Are you happy with no Internet access in your
  life ?

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What Will We Cover? (Tentative schedule)

• Introduction (1.5 2 weeks)
• Internet architecture and design philosophy
• Applications (2-3 weeks)
• HTTP, Email, DNS
• transport services (2-3 weeks)
• reliability congestion control transport
  protocols TCP/UDP
• network services (2-3 weeks)
• routing network protocols IP/IPv6
• link and physical layers (2-3 weeks)
• multiple access Ethernet, FDDI, hubs and bridges

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What Do You Need To Do?

• Your prerequisites
• algorithms e.g. shortest path algorithms
• programming C/C, Java
• basic concepts of operating systems
• Your workload
• reading assignment for every lecture
• homework assignments
• 3 written assignments
• 2 programming projects
• one mid-term exam, and one final exam

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Grading (tentative)
Written Homework 10
Programming work 15
Mid-term exam 30
Final exam 45

• Class participation
• More important is what you learn than the grades

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Questions?
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Outline

• Course information
• What is network?
• A brief introduction to the Internets
• past
• present
• Summary

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Q What is Network?

• Telephone network
• Dialup
• Local area network
• Internet
• Mobile phone

Nodes -- Interconnected
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Why Internet ?

• The most successful network
• Open
• Heterogeneous
• Simple network, complex end-terminals
• End-to-end argument
• How about other networks?
• Telephone
• Mobile phone
• Wireless LAN
• Cable TV
• IP convergence
• And, about the authors of the text book

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Course Information

• Textbook
• Computer Networking A Top-Down Approach
  Featuring the Internet, by Kurose and Ross
• Reference books
• Computer Networks,
• 4/e by Andrew Tanenbaum
• Data and Computer communications, 7th edition ,
  William Stallings, Prentice Hall, 2003

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Motivation Communication

• Need some common interface to communicate ?
  network protocol

• A-gtB Hi
• B-gtA Hi
• A-gtB What time is it ?
• B-gtA 100pm

• What if no protocol

• Woi kx ioa nio ?
• _at_!gt?

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An Example Simple Mail Transfer Protocol (SMTP)

• Scenario
• Email client Outlook, TheBat, NetscapeMail
• Email server in Unix, Windows
• Messages from a client to a mail server
• HELO
• MAIL FROM ltemail addressgt
• RCPT TO ltemail addressgt
• DATAltThis is the text (mail body) end with a
  line with a single .gt
• QUIT
• Messages from a mail server to a client
• status code
• 1xx - Informative message
• 2xx - Command ok
• 3xx - Command ok so far, send the rest of it.
• 4xx - Command was correct, but couldn't be
  performed for some reason.
• 5xx - Command unimplemented, or incorrect, or a
  serious program error occurred.
• mail body

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Internet Standardization Process

• All standards of the Internet are published as
  RFC (Request for Comments)
• but not all RFCs are Internet Standards !
• available http//www.ietf.org
• Till this morning RFC3099
• A typical (but not the only) way of
  standardization
• Internet draft
• RFC
• Proposed standard
• Draft standard (requires 2 working
  implementations)
• Internet standard (declared by Internet
  Architecture Board)

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Internet Standardization Process

• All standards of the Internet are published as
  RFC (Request for Comments)
• but not all RFCs are Internet Standards !
• available http//www.ietf.org
• Till now RFC3866
• A typical (but not the only) way of
  standardization
• Internet draft
• RFC
• Proposed standard
• Draft standard (requires 2 working
  implementations)
• Internet standard (declared by Internet
  Architecture Board)

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Outline

• Course information
• What is a network protocol?
• A brief introduction to the Internets
• past
• present
• Summary

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A Brief History of the Internet

• 1957
• USSR launches Sputnik, US formed Advanced
  Research Projects Agency (ARPA) as a response
• 1968
• Bolt Beranek and Newman, Inc. (BBN) was awarded
  Packet Switch contract to build Interface Message
  Processors (IMPs) for ARPANET

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A Brief History of the Internet

• 1969
• ARPANET commissioned 4 nodes, 50kbps

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Initial Expansion of the ARPANET
Dec. 1969
March 1971
July 1970
Apr. 1972
Sep. 1972
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Multiple Networks

• 1974 Initial design of TCP to connect multiple
  networks
• 1986 NSF builds NSFNET as backbone, links 6
  supercomputer centers, 56 kbps this allows an
  explosion of connections, especially from
  universities
• 1987 10,000 hosts
• 1989 100,000 hosts WELCOME by Leonard
  Kleinrock

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Web and Commercialization of the Internet

• 1991 NSF lifts restrictions on the commercial
  use of the Net World Wide Web released
• 1992 1 million hosts
• Today backbones run at 10Gbps, 100s millions
  computers in 150 countries
• Internet history and Timeline
• http//www.zakon.org/robert/internet/timeline/

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Growth of the Internet in Terms of Number of
Hosts

• Number of Hosts on the Internet
• Aug. 1981 213
• Oct. 1984 1,024
• Dec. 1987 28,174
• Oct. 1990 313,000
• Jul. 1993 1,776,000
• Jul. 1996 19,540,000
• Jul. 2000 93,047,000
• Jul. 2002 162,128,493

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Internet Physical Infrastructure
Local/Regional ISP
BackboneNational ISP
Local/RegionalISP

• Residential Access
• Modem
• DSL
• Cable modem

• Access to ISP, Backbone transmission
• T1/T3, OC-3, OC-12
• ATM, SONET, WDM

• Internet Service Providers
• Local/Regional/National
• They exchange packets at Point of Presence (POP)

• Campus network access
• Ethernet
• FDDI
• Wireless

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Local Access ADSL

• Asymmetrical Digital Subscriber Line (ADSL)
• Telephone companys solution to last mile
  problem

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Local Access Cable Modems

• Fiber node 500 - 1K homes
• Distribution hub 20K - 40 K homes
• Regional headend 200 K - 400 K homes

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ATT US Internet Backbone
From ATT web site.
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Canadian 2G National Internet Backbone
From http//www.canarie.ca/canet4/connected/canet4
_map.html
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ATT Global Backbone IP Network
From http//www.business.att.com
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Web and Commercialization of the Internet
http//research.lumeta.com/ches/map/
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Killer applications - FTP
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Killer applications - Email
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Killer applications WWW 1990-
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Killer applications P2P 2000-
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Killer applications- whats next ?

• Media streaming (Internet TV)
• E-commerce
• Online game

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Summary

• Course information
• Network nodes -gt interconnected
• Protocol format and the order of messages
  exchanged, as well as the actions taken
• Internet The past
• started as ARPANET late 1960s
• initial link bandwidth 50 kbps
• number of hosts 4
• Internet Current
• number of hosts grows at an exponential speed
• July 2002 was
  about 162 millions
• backbone speed 10 Gbps

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Practices

• Log into a Unix machine (or Windows)
• Read the manual of ping and traceroute, and try
  them on a machine
• /bin/ping ltmachine_namegt
• /usr/sbin/traceroute ltmachine_namegt
• Look at the web sites of the routers you see
  through traceroute