1. The Web and Web Services Jim Graham NR 621 Spring 2009

2. Computer Networks 2 or more computers connected together Typically a: –Client: requests and receives data –Server: receives requests and serves data

3. Hardware Connection Phone line/Modem: slow Cable Modem: varies DSL: Up to 8 megabit T3 to T1 Ethernet: Up to 10 gigabit Hardware Connection

4. The Internet Internet: network of computers using the TCP/IP protocol suite –TCP: Transmission control protocol –IP: Internet Protocol Includes IP Addresses Hardware Connection TCP/IP

5. IP Addresses Each computer has an IP address: –128.54.105.1 –Each number can be 0 to 255 –4, 8-bit bytes for 32 bits total Hardware Connection TCP/IP Static IPDynamic IP

6. Internet Protocols http: Hypertext transfer protocol smtp: Small mail transfer protocol ftp: File transfer protocol Hardware Connection TCP/IP Static IPDynamic IP http

7. World-Wide-Web Built on top of the Internet Uses http: hypertext transfer protocol to transfer html: hypertext markup language pages (web pages) The links make it a “Web of Pages” Hardware Connection TCP/IP Static IPDynamic IP http

8. Uniform Resource Locators URL: http://www.niiss.org/jim/home.htmlhttp://www.niiss.org/jim/home.html http: hypertext transfer protocol www.niiss.org: domain namewww.niiss.org –Converted to an IP Address /jim/home.html: path to a file –http://www.niiss.org/jim:http://www.niiss.org/jim Has a default file that redirects to home.html

9. Requesting a Page 1.Client sends an http request with a URL to a server 2.Server find the file based on the URL and returns it 3.Can also request: mpeg, jpeg, gif, etc. HTML Page Request with URL

10. How Web Servers Work Browser ClientServer Web Server HTML File Image File HTML File Image File Internet URL

11. Dynamic Web Pages (server) Browser ClientServer Web Server HTML File Image File HTML File Image File Database Web Script Internet

12. Web Services Program ClientServer Web Server XML File Image File Database Web Script Internet

13. Web Services with VBA