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EECS 122: Introduction to Computer Networks Course Goals and Overview

EECS 122: Introduction to Computer Networks Course Goals and Overview. Computer Science Division Department of Electrical Engineering and Computer Sciences University of California, Berkeley Berkeley, CA 94720-1776. Instructors. Instructors

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EECS 122: Introduction to Computer Networks Course Goals and Overview

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  1. EECS 122: Introduction to Computer Networks Course Goals and Overview Computer Science Division Department of Electrical Engineering and Computer Sciences University of California, Berkeley Berkeley, CA 94720-1776

  2. Instructors • Instructors • Randy Katz (randy@cs.Berkeley.edu), Office Hours: Tu 1-2 PM, W 11-12 noon, and by appointment, 637 Soda Hall • Ion Stoica (istoica@cs.Berkeley.edu), Office Hours: M 5-6 PM, W 4-5 PM, 645 Soda Hall • Textbooks • L. L. Peterson and B. Davie, Computer Networks: A System Approach, 3nd Edition, Morgan Kaufman, San Francisco, 2003. • W. R. Stevens, B. Fenner, A. M. Rudoff, Unix Network Programming: The Sockets Networking API, Vol. 1, 3rd Ed., Addison-Wesley, Boston, 2004.

  3. TAs • Byung-Gon Chun, bgchun@cs.Berkeley.eduTu 4-5 PM, room TBD • Xuanming Dong, xuanming@eecs.Berkeley.eduTime and room TBD • Ling Huang, hling@cs.Berkeley.eduTu 2-3 PM, room TBD • Sonesh Surana, sonesh@cs.Berkeley.eduTime and room TBD • For final office hour schedule, please see the web

  4. Overview • Administrivia • Overview and History of the Internet

  5. Administrivia • Course Web page: • http://inst.eecs.berkeley.edu/~ee122/ • Check often to get the latest information • Deadlines • HWs: due 10:50 am on the indicated date (10 minutes before lecture) • Exams are closed-book, with open crib sheet • Come to office hours, request an appointment, communicate by e-mail • We are here to help, including general advice! • TAs first line for help with programming problems • Give us suggestions/complaints as early as possible

  6. Course Goals • Learn the main architectural concepts and technological components of communication networks, with the Internet as the overarching example • Understand how the Internet works • And why the Internet is the way it is • Apply what you learned in three mini-class projects

  7. Class Workload • NOTE: EE122 is a 4 unit course starting this semester! • Four homeworks spread over the semester • Strict deadlines and due dates (no slip days!) • Three (mini-)projects • 1st and 3rd are part of a larger project, which involves implementing a comprehensive network application • C (or C++) required • 2nd is a simulation project • Two midterm exams • September 30 and November 4 • Final exam • December 16 • Note dates and plan your travel accordingly!

  8. Grading • Consultation on HWs is OK, but must hand in own work • Correlation between understanding HWs and doing well on exams • Course graded to mean of B • Relatively easy to get a B, harder to get an A or a C • 10% A, 15% A-, 15% B+, 20% B, 15% B-, 15% C+, 10% C • A+ reserved for superstars (only 1 or 2 per class) • Mean can shift up for an especially great class

  9. Overview • Administrivia • Overview and History of the Internet • See http://www.isoc.org/internet/history/ for more details

  10. What is a Communication Network?(End-system Centric View) • Network offers one basic service: move information • Bird, fire, messenger, truck, telegraph, telephone, Internet … • Another example, transportation service: move objects • Horse, train, truck, airplane ... • What distinguish different types of networks? • The services they provide • What distinguish the services? • Latency • Bandwidth • Loss rate • Number of end systems • Service interface (how to invoke the service?) • Others • Reliability, unicast vs. multicast, real-time...

  11. What is a Communication Network?(Infrastructure Centric View) • Communication medium: electron, photon • Network components: • Links – carry bits from one place to another (or maybe multiple places): fiber, copper, satellite, … • Interfaces – attach devices to links • Switches/routers – interconnect links: electronic/optic, crossbar/Banyan • Hosts – communication endpoints: workstations, PDAs, cell phones, toasters • Protocols – rules governing communication between nodes • TCP/IP, ATM, MPLS, SONET, Ethernet, X.25 • Applications: Web browser, X Windows, FTP, ...

  12. Network Components (Examples) Links Interfaces Switches/routers Ethernet card Large router Fibers Wireless card Coaxial Cable Telephone switch

  13. Types of Networks • Geographical distance • Local Area Networks (LAN): Ethernet, Token ring, FDDI • Metropolitan Area Networks (MAN): DQDB, SMDS • Wide Area Networks (WAN): X.25, ATM, frame relay • Caveat: LAN, MAN, WAN may mean different things • Service, network technology, networks • Information type • Data networks vs. telecommunication networks • Application type • Special purpose networks: airline reservation network, banking network, credit card network, telephony • General purpose network: Internet

  14. Types of Networks • Right to use • Private: enterprise networks • Public: telephony network, Internet • Ownership of protocols • Proprietary: SNA • Open: IP • Technologies • Terrestrial vs. satellite • Wired vs. wireless • Protocols • IP, AppleTalk, SNA

  15. The Internet (cont’d) • Global scale, general purpose, heterogeneous-technologies, public, computer network • Internet Protocol • Open standard: Internet Engineering Task Force (IETF) as standard body ( http://www.ietf.org ) • Technical basis for other types of networks • Intranet: enterprise IP network • Developed by the research community

  16. Strengths Intelligence at ends Decentralized control Operates over heterogeneous access technologies Weaknesses No differential service Variable performance delay New functions difficult to add since end nodes must be upgraded No trusted infrastructure Strengths No end-point intelligence Heterogeneous devices Excellent voice performance Weaknesses Achieves performance byoverallocating resources Difficult to add new services to “Intelligent Network” due to complex call model Expensive approach for reliability Internet vs. Telephone Net

  17. History of the Internet • 68-70’s: started as a research project, 56 kbps, initially 4 nodes (UCLA, UCSB, SRI, Utah) then < 100 computers • 2 September 2004/35th Anniversary of the Internet • http://www.cnn.com/2004/TECH/internet/08/29/internet.birthday.ap/index.html • 80-83: TCP/IP, DNS; ARPANET and MILNET split • 85-86: NSF builds NSFNET as backbone, links 6 Supercomputer centers, 1.5 Mbps, 10,000 computers • 87-90: link regional networks, NSI (NASA), ESNet (DOE), DARTnet, TWBNet (DARPA), 100,000 computers • 90-92: NSFNET moves to 45 Mbps, 16 mid-level networks • 94: NSF backbone dismantled, multiple private backbones; Introduction of Commercial Internet • Today: backbones run at 10 Gbps, close to 200 millions computers in 150 countries

  18. SRI 940 Utah PDP 10 IMPs UCSB IBM 360 UCLA Sigma 7 BBN team that implemented the interface message processor The ARPANet • Paul Baran • RAND Corp, early 1960s • Communications networks that would survive a major enemy attack • ARPANet: Research vehicle for “Resource Sharing Computer Networks” • 2 September 1969: UCLA first node on the ARPANet • December 1969: 4 nodes connected by phone lines

  19. ARPANet SATNet PRNet TCP/IP NSFNet Deregulation & Commercialization ISP ASP AIP WWW 1965 1975 1985 1995 2005 Web Hosting Multiple ISPs Internet2 Backbone Internet Exchanges Application Hosting ASP: Application Service Provider AIP: Application Infrastructure Provider (e-commerce tookit, etc.) ARPANet Evolves into Internet

  20. Digex Backbone Qwest IP Backbone (Late 1999) GTE Internetworking Backbone Parallel Backbones

  21. Growth of the Internet Number of Hosts on the Internet: Aug. 1981 213 Oct. 1984 1,024 Dec. 1987 28,174 Oct. 1990 313,000 Oct. 1993 2,056,000 Apr. 1995 5,706,000 Jan. 1997 16,146,000 Jan. 1999 56,218,000 Jan. 2001 109,374,000 Jan. 2003 171,638,297 Jan. 2004 233,101,481 Data available at: http://www.isc.org/ Estimated number of users: http://www.internetworldstats.com/stats.htm

  22. Services Provided by the Internet • Shared access to computing resources • telnet (1970’s) • Shared access to data/files • FTP, NFS, AFS (1980’s) • Communication medium over which people interact • email (1980’s), on-line chat rooms, instant messaging (1990’s) • audio, video (1990’s) • replacing telephone network? • Medium for information dissemination • USENET (1980’s) • WWW (1990’s) • replacing newspaper, magazine? • Audio, video (late 90’s) • replacing radio, CD, TV? • File sharing (late 90’s)

  23. Internet Physical Infrastructure Backbone ISP • Residential Access • Modem • DSL • Cable modem • Satellite ISP • Enterprise/ISP access, Backbone transmission • T1/T3, DS-1 DS-3 • OC-3 … OC-76 • ATM vs. SONET, vs. WDM • Campus network • Ethernet, ATM • Internet Service Providers • access, regional, backbone • Point of Presence (POP) • Network Access Point (NAP)

  24. Network “Cloud”

  25. Regional Nets + Backbone Regional Net Regional Net Regional Net Backbone Regional Net Regional Net Regional Net LAN LAN LAN

  26. Backbones + NAPs + ISPs ISP ISP ISP NAP ISP NAP Backbones Business ISP Consumer ISP Dial-up LAN LAN LAN

  27. Core Networks + Access Networks DSLAlways on Cable Head Ends @home Covad Core Networks ISP NAP Cingular NAP Satellite Fixed Wireless Sprint AOL Cell Cell Cell Dial-up LAN LAN LAN

  28. Computers Inside the Core DSLAlways on Cable Head Ends @home Covad ISP NAP Cingular NAP Satellite Fixed Wireless Sprint AOL Cell Cell Cell Dial-up LAN LAN LAN

  29. The Evolution of the Enterprise Late-1980s Internal users Private Corporate Network Limited customer/ external access Dedicated facilities/ computer centers Dedicated applications/ 3rd party DBMS E.g., Oracle

  30. The Evolution of the Enterprise 1995 Internal users Private Corporate Network Limited customer/ external access Dedicated facilities/ computer centers Outsourced “Enterprise Resource Planning” Apps e.g., PeopleSoft, BAAN

  31. The Evolution of the Enterprise 1997 Internal users Virtual Private Network ISP Mesh Internet Outsourced Web Hosting Dedicated Facility Outsourced ERP Apps External Customers

  32. P o r t a l The Evolution of the Enterprise 1997 Internal users Virtual Private Network ISP Mesh Outsourced Web Hosting Internet Dedicated Facility Outsourced ERP Apps Internet Services Search Caching Ads EComm External Customers

  33. P o r t a l The Evolution of the Enterprise 1999 3rd Party Facilities Mgmt Applications Service Provider ISP Mesh VPNs Outsourced Web Hosting Caching + Media Servers Content Delivery “Net” Internet Services Search Cache Ads EComm Customers

  34. Co-Location Scalable Servers WebCaches Services Within the Network: Content Distribution “Internet Grid” Parallel Network Backbones Internet Exchange Points

  35. Register my copy Find me a copy Look here P2P Services in the Internet:Napster, Gnutella, Freenet, … Directory Service . . . Madonna Like a Virgin Madonna Material Girl . . . Grid computing: sharing resources/enabling collaboration

  36. Content Distribution Through MulticastOverlay Network Content Broadcast Network Edge Servers Load Balancing Thru Server Redirection; Content Broadcast Management Platform and Tools RedirectionFabric Inter-ISP Redirection Peering Services Within the Network:Streaming Media Broadcasters Clients Steve McCanne

  37. Summary • Course administrative trivia • Internet history and background

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