1. HTTP Presented By: Holly Mortinson Amy Drout Kyle Balmer & Matt Conklin

2. Agenda Define Key Terms to Understand Foundation of HTTP Define Key Terms to Understand Foundation of HTTP Overview of What HTTP is, Where it Came From, How it Works, and Possible Future Overview of What HTTP is, Where it Came From, How it Works, and Possible Future

3. Key knowledge to understand HTTP World Wide Web: an information space where people can share information from all over the world through the use of computers connected to the internet. World Wide Web: an information space where people can share information from all over the world through the use of computers connected to the internet. How it works: While on the computer, a browser is accessed. The URL address of the information to be retrieved is entered. The enter key is pressed, and the browser sends the URL via HTTP to the server. Then, the server software application retrieves the data, formats it using HTML, and returns the page back to the browser so that it can be viewed. http://www.wikipedia.com

4. Key knowledge to understand HTTP Internet: a worldwide system of interconnected computers that is publicly accessible. Internet: a worldwide system of interconnected computers that is publicly accessible. Web servers: The software application that retrieves the requested data and formats it for display. Web servers: The software application that retrieves the requested data and formats it for display. Browsers: A software application that requests the retrieval of information from the World Wide Web and displays it on your computer. Browsers: A software application that requests the retrieval of information from the World Wide Web and displays it on your computer.http://www.wikipedia.com

5. Key knowledge to understand HTTP HTML (Hypertext Markup Language): Designed for the creation of web pages with hypertext and other information to be displayed in a browser. HTML (Hypertext Markup Language): Designed for the creation of web pages with hypertext and other information to be displayed in a browser. Markup Language: Text and extra information about the text such as the format and structure of the text. Markup Language: Text and extra information about the text such as the format and structure of the text. Hyperlink: A phrase or image that when clicked sends users to another document. Hyperlink: A phrase or image that when clicked sends users to another document.http://www.wikipedia.com

6. Key knowledge to understand HTTP URL (Uniform Resource Locator): A web address or a sequence of characters that is used for referring to resources on the Internet by their location. URL (Uniform Resource Locator): A web address or a sequence of characters that is used for referring to resources on the Internet by their location.scheme://host:port/http://www.wikipedia.com

7. Who invented HTTP and why? Invented by Tim Berners-Lee in 1991 Invented by Tim Berners-Lee in 1991 Provided a way to publish and receive HTML pages Provided a way to publish and receive HTML pageshttp://www.wikipedia.com

8. HTTP defined Hypertext Transfer Protocol Hypertext Transfer Protocol Hypertext: refers to the documents that have hyperlinks Hypertext: refers to the documents that have hyperlinks Transfer: refers to the sending of commands from browsers to web servers Transfer: refers to the sending of commands from browsers to web servers Protocol: agreed upon sequence of characters exchanged between programs with the purpose being to send and receive data Protocol: agreed upon sequence of characters exchanged between programs with the purpose being to send and receive data Stateless: having no information about what occurred previously Stateless: having no information about what occurred previouslyhttp://www.wikipedia.com

9. Purpose of HTTP HTTP is the underlying protocol used to transfer and convey information via the World Wide Web. HTTP is the underlying protocol used to transfer and convey information via the World Wide Web.http://www.wikipedia.com

10. Request Methods GET: requests a representation of the specified resource GET: requests a representation of the specified resource HEAD: asks for the response identical to the one that would correspond to a GET request, but without the response body HEAD: asks for the response identical to the one that would correspond to a GET request, but without the response body POST: submits user data to the identified source POST: submits user data to the identified sourcehttp://webopedia.com

11. Simple HTTP Communication Transaction http://vms.process.com

12. Intermediaries Proxy: forwarding agent Proxy: forwarding agent Receives request in an absolute form Receives request in an absolute form Rewrites all or parts of the message Rewrites all or parts of the message Forwards the reformatted request towards the server originally identified Forwards the reformatted request towards the server originally identified http://vms.process.com

13. Complex HTTP Communication Transaction http://vms.process.com

14. Complex HTTP Communication Transaction with Caching http://vms.process.com

15. Sample HTTP Transaction HTTP Request HTTP Request Client: GET DEFAULT.HTM HTTP/1.0 Accept: text/plain Accept: image/gif/ Accept: image/x-portable-bitmap User-Agent: NCSA WinMosaic 1.0 Client: GET DEFAULT.HTM HTTP/1.0 Accept: text/plain Accept: image/gif/ Accept: image/x-portable-bitmap User-Agent: NCSA WinMosaic 1.0 http://vms.process.com

16. Sample HTTP Transaction HTTP Response Server: HTTP/1.0 200 OK MIME-Version: 1.0 Content-Type: text/html Date: Thursday, 3-AUG-96 23:37:8 GMT Content-Length: 1618 HTTP Response Server: HTTP/1.0 200 OK MIME-Version: 1.0 Content-Type: text/html Date: Thursday, 3-AUG-96 23:37:8 GMT Content-Length: 1618 http://vms.process.com

17. HTTP Versions Current HTTP Current HTTP S-HTTP S-HTTP HTTP/1.2 (PEP) HTTP/1.2 (PEP) HTTP-NG HTTP-NG

18. Current HTTP Leading up to current version. Leading up to current version. HTTP/1.1 HTTP/1.1 Key Features. Key Features.

19. S-HTTP What is it? What is it? Features Features Sample: Sample: https://www.comcast.com/Membership/Login.ashx https://www.comcast.com/Membership/Login.ashx

20. HTTP version 1.2 (PEP) What is it? What is it? How it works? How it works?

21. Where PEP processing occurs The points where PEP processing occurs The points where PEP processing occurs 1. Sending a HTTP request 2. Receiving a HTTP request 3. Sending a HTTP response 4. Receiving a HTTP response Image from http://people.cs.vt.edu/~mfali/ch16

22. HTTP-NG What is it? What is it? How it relates to the future of HTTP How it relates to the future of HTTP

23. Lessons Learned HTTP is a stateless, fast, hypertext transfer protocol HTTP is a stateless, fast, hypertext transfer protocol HTTP is the protocol that underlies the world wide web HTTP is the protocol that underlies the world wide web HTTP defines how messages are formatted and transmitted HTTP defines how messages are formatted and transmitted HTTP defines what actions web servers and browsers should take in response to various commands HTTP defines what actions web servers and browsers should take in response to various commands

24. IMPORTANT TO KNOW!!! HTTP: Hypertext Transfer Protocol HTTP: Hypertext Transfer Protocol What is the purpose of HTTP? What is the purpose of HTTP? It is the underlying protocol used to transfer and convey information via the World Wide Web. What are the 3 most used HTTP requests methods? What are the 3 most used HTTP requests methods?

25. References http://wwww.webopedia.com http://wwww.webopedia.com http://wwww.webopedia.com http://www.wikipedia.ort http://rhyshaden.com http://vms.process.com http://people.cs.vt.edu