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CMPT 371 Data Communications and Networking. Fall 2004. Outline. Course information What is network? A brief introduction to the Internet’s past present Summary. Course Information. Instructor: Jiangchuan (JC) LIU Room 10826, Applied Science Building
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Outline • Course information • What is network? • A brief introduction to the Internet’s • past • present • Summary
Course Information • Instructor: • Jiangchuan (JC) LIU Room 10826, Applied Science Building • E-mail: jcliu@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@cs.sfu.ca )
Course Information • Time & Venue • Wednesday 17:30-20:20pm • RC Brown 8100 • There will be one or two breaks
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
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
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 ?
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
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
Class participation More important is what you learn than the grades Grading (tentative)
Outline • Course information • What is network? • A brief introduction to the Internet’s • past • present • Summary
Q: What is Network? • Telephone network • Dialup • Local area network • Internet • Mobile phone • … Nodes -- Interconnected
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
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
Motivation: Communication • Need some common interface to communicate network protocol • A->B: Hi • B->A: Hi • A->B: What time is it ? • B->A: 1:00pm • What if no protocol… • Woi kx ioa nio ? • #@!>? … • …
user agent user agent user agent user agent user agent user agent SMTP SMTP SMTP POP3, IMAPSMTP mail server mail server mail server outgoing message queue user mailbox 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: <email address> • RCPT TO: <email address> • DATA<This is the text (mail body) end with a line with a single .> • 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
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)
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)
Outline • Course information • What is a network protocol? • A brief introduction to the Internet’s • past • present • Summary
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
A Brief History of the Internet • 1969 • ARPANET commissioned: 4 nodes, 50kbps
Initial Expansion of the ARPANET Dec. 1969 July 1970 March 1971 Apr. 1972 Sep. 1972
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 hostsWELCOME by Leonard Kleinrock …
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/
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
Internet Physical Infrastructure Local/Regional ISP Backbone:National ISP Local/RegionalISP • Residential Access • Modem • DSL • Cable modem • Internet Service Providers • Local/Regional/National • They exchange packets at Point of Presence (POP) • Access to ISP, Backbone transmission • T1/T3, OC-3, OC-12 • ATM, SONET, WDM • Campus network access • Ethernet • FDDI • Wireless
Local Access: ADSL • Asymmetrical Digital Subscriber Line (ADSL) • Telephone company’s solution to “last mile problem”
Local Access: Cable Modems • Fiber node: 500 - 1K homes • Distribution hub: 20K - 40 K homes • Regional headend: 200 K - 400 K homes
AT&T US Internet Backbone From AT&T web site.
Canadian 2G National Internet Backbone From http://www.canarie.ca/canet4/connected/canet4_map.html
AT&T Global Backbone IP Network From http://www.business.att.com
Web and Commercialization of the Internet http://research.lumeta.com/ches/map/
Killer applications- what’s next ? • Media streaming (Internet TV) • E-commerce • Online game • …
Summary • Course information • Network: nodes -> 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
Practices • Log into a Unix machine (or Windows) • Read the manual of ping and traceroute, and try them on a machine • % /bin/ping <machine_name> • % /usr/sbin/traceroute <machine_name> • Look at the web sites of the routers you see through traceroute