COM 205 Multimedia Applications

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COM 205Multimedia Applications

• St. Josephs College
• Fall 2004

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Chapter 12

• The Internet and How It Works

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HISTORY

• A. ARPANET
• 1. The Internet was created in 1969 by the
  Advanced Research Projects Agency (ARPA).
• a) ARPA was part of the U.S. Department of
  Defense.
• b) The ARPANET grew as it networked universities,
  military sites, and government agencies.
• 2. In 1985, National Science Foundation (NSF)
  used ARPANET to connect supercomputers and
  computer science centers.
• a) Management of the ARPANET officially passed to
  the NSF in 1989.
• 3. Commercial use of the Internet began in 1992.

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Internetworking

• Networking basics
• 1. Two or more computers connected to each other
• make a network.
• 2. A local network is called a local area network
  
• (LAN).
• 3. Distant LANs can be connected via phone lines
• or another medium to form a wide area network
  (WAN).
• 4. LANs, WANs, and individual computers can
• also connect to the Internet through a server.
• a) A server is permanently connected to the
  Internet through a high-bandwidth physical
  connection

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Internetworking

• TCP/IP is the protocol used for communicating on
  the Internet
• TCP is Transmission Control Protocol
• IP is the Internet Protocol
• In 1983 the Domain Name System (DNS) was
  established to assign names to computers which
  were linked to the Internet.

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Internet Addresses

• 1. Address syntax
• a) Internet addresses use the following syntax
• protocol//domain name/path/file
  name
• ( http//www.sjcny.edu) for example
• b) The server directory path and file name are
• often left off.
• c) The protocol usually does not need to be
  typed.
• d) The protocol is also often hidden, such as
• (1) mailto
• (2) news

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Internet Addresses

• 2. Top-level domains (TLDs)
• a) The current Domain Name System (DNS) was
  developed in 1983.
• b) TLDs were established for various categories.
• c) The TLD is part of the domain name, such as
• (1) .com
• (2) .net
• (3) .gov
• (4) .mil
• (5) . edu
• (6) Two-letter country codes

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Domain Name System ( DNS)

• In 1998 (ICANN) Internet Corporation for Assigned
  Names and Numbers was set up to oversee the DNS.
• In 2000, ICANN approved seven new TLDs
• aero info pro
• biz museum
• coop name

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Domain Name System ( DNS)

• Other names are under discussion and may be added
  in the future
• web
• arts
• shop
• firm
• nom
• rec

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IP Addresses and Data Packets

• A The Internet transmits data using the
  Transmission Control Protocol (TCP).
• (1) Data is broken up into packets.
• B The Internet Protocol (IP) transmits the
  packets.
• (1) Packets can travel along various paths and
  are reassembled at the receiving end.
• (2) Destinations are identified by numeric IP
  addresses such as 140.174.162.10
• (3) Domain name servers look up these addresses.

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Connections

• 1. To connect to the Internet, a computer or
  network needs
• a) A data connection to a server
• (1) The data connection can be wireless or a land
  line.
• (2) You usually need an account with the server.
• (3) Most people access a server through an
  Internet service provider (ISP).
• b) TCP/IP software
• (1) Your operating system may need to be
  configured to connect to the server and use
  TCP/IP software.

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Connections

• c) Internet software includes
• (1) E-mail programs
• (2) Web browsers
• (3) FTP software
• (4) News readers
• d) ISP ( Internet Service Providers) software
• PPP - (Point to Point) for dialing up
• TCP/IP for sending and receiving
• POP (Point of Presence) - local telephone number

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Bandwidth Bottleneck

• 1. Bandwidth is how much data, you can send
  from one computer to another in a given unit of
  time ( See p. 337)
• 2. The bandwidth bottleneck
• a) Bandwidth is measured in bits per second
  (bps).
• b) Available bandwidth greatly affects how a
  person can use the Internet.
• c) Users with slow connections will have a
  difficult time using multimedia over the Internet.

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Bandwidth Bottleneck

• d) To accommodate low bandwidth users
• (1) Compress data when possible.
• (2) Take advantage of the browsers cache.
• (3) Design for download efficiency- dont overdo
• animation, colors, etc.
• (4) Design alternate sites for low- and
  high-bandwidth
• users.
• (5) Consider using streaming technology.

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Internet Services

• 1. Services include http, ftp, telnet, Usenet,
  SMTP, IRC, and others.
• a) Some services, such as Gopher, are not
  commonly used.
• 2. Multipurpose Internet Mail Extensions
  (MIME)-types
• a) Files used online must conform to Internet
  protocols.
• b) Data types are identified using MIME-types.
• c) File types must be recognized by servers to be
  used on the Internet.

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The World Wide Web and HTML

• A. Web history
• 1. Tim Berners-Lee of CERN (the European Particle
  Physics Laboratory) developed the Webs hypertext
  system in 1989.
• a) The Hypertext Transfer Protocol (HTTP) was
  designed as a means for sharing documents over
  the Internet.
• b) The Hypertext Markup Language (HTML) is the
  markup language of the Web.
• c) Cross-platform compatibility was a design goal.

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HTTP

• The Hypertext Transfer Protocol ( HTTP) provided
  rules for a simple transaction
• 1. Establishing a connection
• 2. Requesting that a document be sent
• 3. Sending a document
• 4. Closing the connection

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HTML

• The HTTP protocol also required a simple document
  format called HTML (Hypertext Markup Language)
  for presenting text and graphics
• The HTML document can contain hotlinks which a
  user can click to jump to another location

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Dynamic Web pages and XML

• 1. Advanced tools can be used to make a Web page
• dynamic.
• a) Dynamic technologies include
• (1) Cold Fusion (CFM)
• (2) Hypertext Preprocessor (PHP)
• (3) Active Server Pages (ASP)
• (4) Java Script and Java Applets
• b) Dynamic pages work in conjunction with
  database applications to look up data.

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(XML) eXtensible Markup Language

• a) XML goes beyond HTML and is the next step in
  developing web pages.
• b) This markup language allows developers to
  define their own styles and elements.
• c) It allows you to create your own tags to
  describe what the data means
• d) Whether or not XML is the future of Web design
  is still somewhat questionable.
• Check www.xml.org and www.xml.com

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Multimedia on the WEB

• Developers need to understand how to create and
  edit elements of multimedia and also how to
  deliver it for HTML browsers
• The number of new users of the web will create a
  greater need for high quality, compelling
  content, and reasonably quick presentations

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Project Idea

• Visit these web sites
• http//www.navy.com/
• http//www.sigov.si/
• http//www.w3.org/MarkUp/Guide/Style.html
• For each address, answer the following questions
• What is the title of the Web page?
• Briefly describe the content of the Web page.
• What is unique about the URL?