Welcome to CSC667/867

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Welcome to CSC667/867

• Internet Application Design and Development
• Dr. Ilmi Yoon

NOTE Course note courtesy to Ellis Horowits (USC
CS571) and PrenticeHall (Deitel Associates).
The materials are modified to fit to CSc667/867
with permissions from authors.
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Topics what you will learn

• Web Application Architecture
• Principles, Protocols and Practices
• Understanding of core technology, not platform
  specific knowledge
• Pre-WWW, Internet, TCP/IP
• Web Server, Browser, HTTP
• Client side technologies
• Server side technologies
• E-commerce system DB connections
• Web application development Deployment
• XML and its applications
• Emerging technologies
• Web services, Semantic Web, Data exploration, 3Ds
  on the WWW, Security and more

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Course Overview

• Mechanism and various technologies of Internet
  applications through projects
• Develop your own web server (using JAVA)
• 2 people team project
• Experiment JavaScript/Python CGI project
• Individual project
• Develop and Deploy an Internet application
• 4 people team project
• Advanced Issues
• Most of all, not only knowledge, you will learn
  the experience of building large application,
  team work, searching for necessary information
  from given large resources and build confidence
  in yourself!

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Course Overview

• Going through course overview using printed
  syllabus
• exams, grading policy, late penalty
• Survey

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Announcements

• TA Berdnt Jung (Thu 200 300)
• Participating in Annotizer project using course
  web site
• Start to think of term project as early as
  possible!!!
• IOC Project (presentation by Gauri)
• Art work on view (www.artworkonview.org )
• SFSU CS Alumni site
• WICE (Web-based Interactive Computing
  Environment)
• HTML 1 2 for self study
• Assignment 1 is now available on the course web
  site

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• Any Questions?
• Then, lets get started!!!

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Defining the World Wide Web

• A wide-area hypertext, multimedia information
  retrieval system that provides access to a large
  universe of documents
• A uniform way of accessing and viewing some
  information on the Internet
• The WWW
• creates a world in which information has a
  reference by which it can be accessed
• subsumes the capabilities of ftp, gopher, wais
  and news

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History of the World Wide Web

• WWW
• Allows computer users to locate and view
  multimedia-based documents
• Introduced in 1990 by Tim Berners-Lee for
  astrophysicist to share documents
• Internet today
• Mixes computing and communications technologies
• Makes information constantly and instantly
  available to anyone with a connection

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The Internet and the WWW are Different

• The Internet is a global digital infrastructure
  that connects millions of computers and tens of
  millions of people
• The World Wide Web is a mechanism that unifies
  the retrieval and display of a subset of data on
  the Internet
• An intranet is a local/global information
  structure that connects an organization internally

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Major Technology Components

• Client/server architecture
• where client programs interact with web servers
• Network protocol
• HTTP, Hypertext Transfer Protocol, is the
  language understood by browsers and web servers
• designed to move quickly from document to
  document
• Addressing system (Uniform Resource Locators)
• http//domain/directory/file.html
• Markup Language
• every web server understands and every browser
  displays
• includes support for Hypertext and multimedia

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Basic Internet Definitions

• http//www.pierobon.org/iis/ by Pierobon
• Simple definitions for LAN, WAN, Internet, WWW,
  Hypertext, Intranet, Extranet, Protocol, TCP/IP,
  UDP, Address, Domain, Domain Name, Plug-in, URL,
  URI, socket and a short quiz!

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Client/Server Architecture Model
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The WWW Server

• Web browsers and Web servers communicate
  according to a protocol known as HTTP (HyperText
  Transfer Protocol)
• The current HTTP protocol is version 1.1
• The Web server is a software system running on a
  machine often called the Web server, dont
  confuse them
• A web server can
• receive and reply to HTTP requests
• retrieve documents from specified directories
• run programs in specified directories
• handle limited forms of security
• A web server does not
• know about the contents of a document, links in a
  document, images in a document or whether a
  particular file, e.g. a .gif file, is in the
  correct format

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Uniform Resource Locator

• A mechanism whereby an Internet resource can be
  specified in a single line of ASCII text
• 1. Scheme followed by a colon http,ftp,gopher,n
  ews,mailto,wais,telnet
• file//pub/xt.ps (a PostScript file in
  directory pub on your local machine)
  ftp//cs.sfsu.edu/docs/sweng.txt (a file
  sweng.txt in directory docs on cs.sfsu.edu, an
  anonymous ftp) http//nunki.usc.edu/mydocs/book.do
  c (a file in directory mydocs on machine
  nunki.usc.edu)
• 2. Double slash (only for http, ftp, gopher,
  wais) //
• 3. Internet domain name e.g., cs.sfsu.edu
• 4. Port number (this field is optional e.g.,
  pollux.usc.edu8081)
• -- Standard or default port numbers
• --- ftp is 21 gopher is 70
• --- telnet is 23 http is 80
• --- smtp is 25 nntp is 119
• 5. Path e.g., /pub/docs

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Markup Languages

• HTML - hypertext markup language, specifies
  document layout and the specification of
  hypertext links to text, graphics and other types
  of objects
• browsers display text and graphics using the
  markup as guidance
• However, HTML is not like a word processing
  program, e.g. Microsoft Word or WordPerfect, and
  not like a page description languages, e.g.
  postscript
• as a result, translation into HTML can produce a
  result that does not look exactly like the
  original
• XML (extensible markup language)

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History of the Internet

• ARPAnet
• Implemented in late 1960s by ARPA (Advanced
  Research Projects Agency of DOD)
• Networked computer systems of a dozen
  universities and institutions with 56KB
  communications lines
• Grandparent of todays Internet
• Intended to allow computers to be shared
• Became clear that key benefit was allowing fast
  communication between researchers
  electronic-mail (email)

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History of the Internet (II)

• ARPAs goals
• Allow multiple users to send and receive info at
  same time
• Network operated packet switching technique
• Digital data sent in small packages called
  packets
• Packets contained data, address info,
  error-control info and sequencing info
• Greatly reduced transmission costs of dedicated
  communications lines
• Network designed to be operated without
  centralized control
• If portion of network fails, remaining portions
  still able to route packets

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History of the Internet (III)

• Transmission Control Protocol (TCP)
• Name of protocols for communicating over ARPAnet
• Ensured that messages were properly routed and
  that they arrived intact
• Organizations implemented own networks
• Used both for intra-organization and
  communication
• Huge variety of networking hardware and software
  appeared
• ARPA achieved inter-communication between all
  platforms with development of the IP
• Internetworking Protocol
• Current architecture of Internet
• Combined set of protocols called TCP/IP

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History of the Internet (IV)

• The Early Internet
• Limited to universities and research institutions
• Military became big user
• Next, government decided to release Internet for
  commercial purposes
• Internet traffic grew
• Businesses spent heavily to improve Internet
• Better service for their clients
• Fierce competition among communications carriers
  and hardware and software suppliers
• Result
• Bandwidth (info carrying capacity) of Internet
  increased tremendously

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http//www.isc.org/ds
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Network Basics

• A host is a computer that is enabled to function
  on a network
• any set of hosts connected in such a way that any
  two hosts can send and receive messages is called
  a network
• a protocol is the method by which two computers
  agree to communicate
• an address space is the set of names of computers
  that can be referenced

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LAN Internet Access

• Speak TCP/IP and add a Domain Name Server
• A router may be located either at your site
• or at your ISP

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IP and TCP/IP

• To be a host on the Internet your computer must
• have a host/domain name, e.g. tlaloc.sfsu.edu
• be assigned a unique IP address, e.g. 128.125.2.1
  (static or dynamic IP)
• use the Internet protocol
• have a network connection that provides a route
  to the Internet

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IP Addresses

• An IP address is a 32-bit number, from 0 to about
  4.3billion
• These numbers are written as four sets of eight
  bits each, network.subnetwork.subnetwork.computer
• The next generation of IP is IPv6
• it uses a 128 bit address space

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Internet Domain Names

• A domain name has the following form
• subdomain.subdomain..domain
• E.g. my email address includes my name, host and
  domain name, yoon_at_cs.sfsu.edu
• U.S. domains are divided into the following
  logical categories
• com commercial and industrial organizations
• edu educational institutions
• gov non-military, government affiliated
  organizations
• mil military organizations
• net network operations
• org other organizations and user groups

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Reading Assignment

• Read Chapter 1 2 from Web Application
  Architecture
• Definitions of web page, web site, web
  application
• TCP/IP,Telnet, SMTP (Simple Mail Transfer
  Protocol), POP (Post Office Protocol), IMAP
  (Internet Message Access Protocol)
• Extra credit for those who read these chapters
  and write a short summary report and post its url
  at course web site using Annotizer
• Read Basic Internet Definitions and take the
  quiz, print out and bring it back to classroom