CS 3870/CS 5870 Welcome! Web Protocols, Technologies and Applications

Who am I? Name: Dr. Qi Yang (call me “Qi”) Office: Ullrich 213; office hours, see web: Education: –BS in Math: Sichuan University, China, 1982 –MS in CS: University of Illinois at Chicago, 1989 –PhD in CS: University of Illinois at Chicago, th year at UW—Platteville

Syllabus

4 What is a Computer? Storage CPU MEMORY Input Output Network

5 Local Network at UWP File Server: J:\, S:\, O:\ Apps Rights … Ull 213 Ull 002 Res Hall Bears Den...Lab 207

6 The Internet UWP Townsville Australia SWUN Darmstadt Germany UW.....

The Internet A “network of networks” Origins: –Kleinrock (1960s): click herehere –ARPANET (1969): click herehere Domain name system (DNS) –Maps numeric “IP” addresses to “domain” names –1982: HOSTS.TXT –Now: distributed, hierarchical database Core protocols: TCP/IP

8 TCP/IP Transmission Control Protocol / Internet Protocol Turing Award

9 Internet Applications Simple Mail Transfer Protocol (SMTP)SMTP Post Office Protocol (POP)POP Internet Messaging Access Protocol (IMAP)IMAP Telnet: remote terminalTelnet FTP: File Transfer ProtocolFTP Gopher...Gopher...

10 Internet Applications Console Applications GUI Applications

11 World Wide Web (WWW) GUI Internet Application Information Super High Way Business Household HTTP: Hyper Text Transfer Protocol HTML: Hypertext Makeup Language W3C - World Wide Web Consortium

Application Protocols HTTP HTTPS SMTP POP IMAP FTP SOAP … All are based on TCP/IP 12

13 A Brief History of the WWW CERN 1989 (Geneva European Laboratory for Particle Physics) Initial Proposal A common and consistent user interface Incorporation of a wide range of technologies and document types A “universal readership” 1990: first line browserfirst line browser 1992: a few browsers and 50 web sites 1993: Mosaic browser for X Windows at NCSA (UIUC), 500 web sites Since 1994: more browsers, web sites, web servers, search engines Click here

14 WWW Basics –Web sites: Web content providers –Web browsers –Hypertext Transfer Protocol (HTTP) –Hypertext Markup Language (HTML) –Uniform Resource Locator (URL) –Web navigation and search tools –Gateways to non-Web resources –XML (eXtended Markup Language) –XHTML (Extensible HyperText Markup Language) –…–…

What makes up a website? Three main components to every website: 1.Web server (always-on program listening for requests from web browsers) 2.Web objects (text and binary documents) 3.Web browser – Not really part of a website—or is it? – If a tree falls in a forest but nobody is around to hear it, does it make a sound?

Web browsers GUI, Client-Server application Request content from web servers Download and display content to user First GUI browser What browser do YOU use? URL: Uniform/Universal Resource Locator

URL Format protocol://host:port/path Protocol http, https, ftp, telnet, etc. Host IP address or name of server (DNS) Port default: 80 Path Where to find the desired web object

18 HTTP Application-level protocol For collaborative, distributed, hypermedia information systems Client-Server LOTC Locate Open Transfer (request/response) Close

19 HTTP Connection Request URI Method GET, HEAD, POST, PUT, DELETE Example: GET /index.html HTTP/1.1\r\n Server Response: 200, 403, 404, etc. Close

20 HTML Display data in browser using tags HTML History Patent

21 HTML If you don’t know HTML, don’t worry View page source You must teach yourself HTML Basic HTML elements UWP Web Training Center

22 Non-Web Resources Legacy systems Databases

Advanced Web Technologies CGI (Common Gateway Interface) PHP Java Applets ASP.NET … 23

24 WWW and Windows Programs Windows Program Variables to keep track of state WWW and HTTP Stateless “Universal Readership” Web Applications How to keep state information?

Lab 1 Due 9:30 PM, Friday, September 6 Class DropBox: S:\Courses\CSSE\YangQ\CS3870\DropBox 25