EN3515 Lecture 4: Networking and the Internet

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EN3515 Lecture 4Networking and the Internet

• Net Spaces
• Case Studies
• Network Hardware
• Network Software
• Network Standards/Protocols
• Internet Communication Strategies
• Evaluating Good Websites

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Net Spaces

• The landscape of Cyberspace
• The Matrix (main part of cyberspace
• The Internet
• FTP space
• Telnet space
• Gopher space
• WAIS space
• Web space
• Email space
• Usenet
• BITNET
• Commercial Services
• Private Nets

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Cyberspace The Matrix
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FTP Space

• The set of all resources accessible through the
  File Transfer Protocol on the Internet. The
  resources include directories of files and
  individual files that might be text or binary
  (executables, graphics, sound, and video) files.
  It is among the oldest spaces on the Net and has
  massive and often obsolete and polluted
  information on it. It is a major distribution
  area for software.
• Recent trend of Files Transfer on Internet P2P

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FTP Keyword Searcher

• There is no way to search the contents of
  documents at FTP sites. The only alternative is
  to use Archie--a tool that indexes the filenames
  at FTP sites and is good for looking for a
  software or shareware program of a particular
  name. Most of these old world Internet
  resources are integrated by WWW today.

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Telnet Space

• Telnet is a protocol for remotely logging into a
  remote computer. Many Telnet sites still offer
  valuable and updated information (i.e. card
  catalogs of libraries). Using Telnet, you can
  also access your own e-mail account from a long
  distance.
• Example
• Telnet//personal.cityu.edu.hk

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Gopher Space

• Gopher, an information system designed at the
  University of Minnesota, is among the oldest
  spaces on the Net. Because of the rise of the
  Web, the Gopher traffic on the Net has declined.
  Here is the mother of all Gophers at the
  University of Minnesota
• http//www.webopedia.com/TERM/g/gopher.html

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Gopher Subject Tree

• A good collection of subject-related Gophers is
  Gopher Jewels. A Web-version is at
• http//galaxy.einet.net/GJ/index.html
• The Internet search engine history
• http//www.galaxy.com/info/history2.html

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Case Studies

• Build a peer-to-peer LAN
• Build a client-server LAN
• Build New Media Lab LAN
• From CityU to Internet

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Build a Peer-to-Peer Network

• Minimal items needed
• 2 computers, each with a network card
• a crossover cable, or a cable and a hub
• Windows 3.11/95/98 on all computers

(or crossover cable)
Hub
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The buzz word of peer-to-peer network (P2P) kazaa

• http//www.download.com 1 download!!
• Lets do a search on wired.com with kazaa

server
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Server/Client Network

• Minimal items needed
• a server with networking software
• 2 workstation
• a hub (or switch)
• Network cables

Link to outside network(s)
Server
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New Media Lab LAN (example)

• Servers
• NT server primary controller, printer server,
  file server, and secondary Web server
• Win2000 server primary Web server
• Workstations
• 28, running Windows XP, with some of these
  connected to overhead projector, sound system,
  scanners, CD-writers, and video conferencing
  systems

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The NML LAN (2)

• Servers, workstations, and printers are connected
  through 100BASE-T cable (100mps) to designated
  ports on LAN switches
• The Lab LAN is connected to the Internet via
  CityU ATM backbone network (154mps)
• A router shields the Lab LAN from CityU-EN LAN
  (i.e., making the Lab a subnet of the LAN), to
  separate the resources/broadcast messages between
  the two LANs

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The NML LAN (3)
CityU Staff LAN
scanner
Internet
EN Staff LAN
V-Con
NT
Unix
Router
24-port Switch
16-port Switch
V-Con
scanner
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From LANs to Internet
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From CityU to the Internet
Media Lab
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Network vs. the Internet

• Network
• LAN (private, closed system)
• WAN (LAN extended to a larger area)
• Intranet, Extranet, and the Internet
• Intranet (LAN or WAN using Internet connection)
  Example CityU Portal
• Extranet (Intranet extended to associates)
• The Internet (a public, open system)

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Internet vs. World Wide Web

• Internet is the physical infrastructure on the
  global scale whereas WWW is one of the following
  protocols (i.e., software standards) that run on
  the Internet
• http (for WWW)
• ftp (file transfer protocol)
• telnet (remote login protocol)
• gopher (text-based WWW)
• mailto (e-mail)

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Networking Standards

• Protocol for connection
• TCP/IP (most popular)
• IPX (Novells proprietary system)
• NetBIOS/NetBEUI (easy, fast, from Microsoft, for
  P2P LANs)
• IP Address
• Classes (c.l.l.l c.c.l.l c.c.c.l)
• Default gateway (usually the last in the net)
• Subnet mask (usually 255.255.0.0)

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IP Address

• An IP address is a unique identification for any
  computer connected to the Internet.
• All IP addresses are in the form of x.x.x.x
  (where x has 8 bits ranges from 0 to 255).
• IP addresses are assigned at levels
• Global authority Network Solutions, Inc.
• Local authority the network administrator of
  your organization

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Classes of IP Address
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IP Address vs. Internet Address

• IP address (a 4-quad numeral) identifies a
  computer connected to the Internet (e.g.,
  144.214.44.x for our NT server)
• Internet address (a literal of any length)
  identifies a Web server (e.g., newmedia.cityu.edu.
  hk for the NT server) or a subdirectory of a Web
  server (e.g., newmedia.cityu.edu.hk/en5611)
• Web server can be a server or a workstation with
  a fixed IP address and a hardwire connection

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Dynamic IP Address and Dial-up Connection

• A dynamic IP address is assigned by a network
  server during the connection time (often through
  a dial-up means)
• A computer is typically assigned a different
  dynamic IP address each time connected
• Dial-up connection involves modem-phone line (up
  to 56kps), or ISDN (Integrated Service Digital
  Network, 128kps), or ADSL, xDSL, or cable modem

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Next Generation of IP Address IPv6
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IP Address
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Other trend of WWW

• Connect to the next PPT file

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Internet Communication Fundamentals Strategies

• Effects a communication perspective
• Unique features of the Internet (Web) as a
  communication medium
• Web design setting reasonable goals
• Types of Web design
• Basic elements of good Web Sites
• Dos and donts in Web design

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Effects A Communication Perspective

• A simple hierarchy of communication effects
• Behavior (actions, performances)
• Attitude (beliefs, values, opinions, judgments)
• Emotion (feelings, likes)
• Cognition (knowledge, information, thinking
  process)

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Effective Communication

• Communication that comes from trusted sources,
  reaches the targeted audience with appropriate
  format (means and channels) and content, and
  achieves the intended goals.

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Unique Features of Internet as a Communication
Means

• Although the Internet has inherited some
  features from the traditional media, it is
  distinct in several ways
• Interactivity
• Non-linearity (hypertext and hyperlink)
• Multimedia capability
• Porous quality (in pieces)
• Varying speed (connection speed dependent)
• Varying browsers (IE, Netscape, Mozilla, Opera,
  etc.)
• Varying display (monitors, mostly 14 and 15)
• Almost unlimited choices (too many possible
  links!!)

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The 28.8Kbps Factor

• About one-third of the people using the Internet
  are connected through 28.8Kbps modems. A bit --
  a contraction of the phrase binary digit --is the
  most elemental unit of computer information,
  either a 1 or a 0. One byte is made up of 8
  bits. Therefore, a 75KB (75,000-byte) file would
  take 20.8 seconds to transfer at 28,800 bits per
  second.

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Web recent trend

• From text-based, to more graphically-represented.
  From more passively transfer information, to more
  interactive, or even more immersive
  (immersed)
• Example http//flysworkshop.net/as/
• Example http//www.activeworlds.com/ or
  http//www.worlds.com

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Internet Communication Goals

• General goals
• Information
• Entertainment
• Service
• Marketing
• Persuasion
• Pure presence

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Internet Communication Goals(Marketing)

• Some specific goals in marketing
• Brand-building
• Direct marketing
• Online sales
• Customer support
• Market research
• Content publishing/services

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Three Major Types of Web Sites

• Brochureware
• Show-biz
• Utilitarian

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Brochureware

• Brochureware sites are the most commonly deployed
  ones on the Web. They are normally static,
  non-interactive and boring about-my-business
  sites.

http//www.spam.com/
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Show-biz

• Show-biz sites mean two things First, those
  misguided attempts to lure visitors to shows of
  products second, flashy and showy sites that
  feature technical dexterity.
• Example Liptons margarine http//www.tasteyoulo
  ve.com/

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Utilitarian

• Utilitarian sites are those that offer Web
  surfers a genuine service and experience -- an
  interactive information/service utility. Federal
  Expresss (FedEx) site is a classic example.

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Schools of Web Design

• Early ASCII text
• Classic three-part Web page
• Modern graphic slabs
• Postmodern fragments
• Early virtual 2D/3D scene, metaphor

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Early ASCII Text

• Influenced by the hierarchical organization
  common in previous information systems such as
  Gopher, FTP and Telnet, the early ASCII design
  style relies heavily on hierarchical organization
  and links to extend meaning. This school is
  obsolete.
• Example a telnet web page design.

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Early ASCII Page Example
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Classic Three-Part Web Page

• The classic three-part structure of head, body
  and column is popular with the use of graphical
  browsers because the visual impact of a single
  screen has more visual impact that the scrolling
  browsers, such as the Lynx browser.
• Example our course site

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Modern Graphic Slabs

• Marked by the use of graphics to draw attention,
  reveal choices and provide ornament, this style
  runs the gamut of expressions ranging from a
  single-graphic slab to a mixture of graphics and
  text often arranged in a grid to reveal
  functionality.
• Examples compare whitehouse.gov and amazon.com

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Postmodern Fragments

• Instead of conceiving a page as a fixed
  structure, a postmodern style generates a page
  based on user requests by the use of CGI
  programming to dynamically create web pages and
  graphics on the fly.
• Example HotWired (http//www.hotwired.com/membe
  rs/)

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Early Virtual Scene

• The early virtual page involves Virtual Reality
  Modeling Language (VRML) and can be viewed as an
  environment in which the room or the scene
  becomes a unit of attention for the user.
• VRML
• Adobe Atmosphere
• Digital Space
• Activeworlds..etc.
• http//www.taj-mahal.net/blackBack.htm

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Elements of Good Web Sites

• Good sites are good communities
• Good sites are relevant (e.g. personalized
  content)
• Good sites entertain (pleasing)
• Good sites do not stand alone (linked)

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Some Dos in Web Design

• Know your audience
• Build in interactivity and feedback (when
  necessary)
• Provide good and user friendly navigation
• Create consistent, pleasing and efficient look
  and feel
• Keep files short and small (45KB or below per
  page)
• Content, content, content
• Link to most relevant resources
• Use graphics and multimedia only when they are
  necessary and efficient

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Some Donts in Web Design

• Avoid
• monster page overloaded with information
• multimedia overkill example1
• meaningless links
• clown pants (disorganized pages)
• KOOL design (overly fancy but empty sites)
• sukers
• worst websites

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Evaluating Standards and Strategies (1)

• Basic assessment
• The Internet is an invaluable source of
  information, communication, and interaction. It
  contains diverse information, some of which is
  good and some of which is garbage.

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Evaluating Standards and Strategies (2)

• How to evaluate the information on the Net
  depends on the purposes and needs of the user.
• Some basic needs
• 1. Factual information 2. Entertainment
• 3. Socialization 4. Escape/diversion
• 5. Services 6. Business

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Evaluating Standards and Strategies (3)

• Basic standards
• Accuracy Reliability
• Authenticity Readability/Ease
• Authority Utility
• Accessibility Stability
• Currency Links
• Interactivity Security

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Evaluating Standards and Strategies (4)

• Some good information providers
• 1. Academic institutions/experts
• 2. Tradition mass media
• 3. Government organizations (i.e., U.S. Census)
• 4. Major corporations
• 5. Reputable newsgroups/sites

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Evaluating Standards and Strategies (5)

• Some strategies
• 1. Lists of top (good) sources
• 2. Frequently visited sources
• 3. Frequently linked sources
• 4. Databases provided by professional providers

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Evaluating Standards and Strategies (6)

• Ten things to bear in mind
• 1. Traffic might be heavy.
• 2. Servers can go down.
• 3. The Net can go down.
• 4. Resource names can change.
• 5. Resources can disappear.
• 6. Resources can be HUGE.
• 7. Links can break.
• 8. Your senses might be overloaded.
• 9. You might be shocked.
• 10. You can get sick.