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HTTP, the hypertext transfer protocol. S kills : none Concepts : protocol, hypertext transfer protocol, standard. This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 License. Where does this topic fit?. Internet concepts Applications Technology
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HTTP, the hypertext transfer protocol Skills: none Concepts: protocol, hypertext transfer protocol, standard This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 License.
Where does this topic fit? • Internet concepts • Applications • Technology • Implications • Internet skills • Application development • Content creation • User skills
1. Establish a temporary connection between the client and server 2. Client sends the request to the server 3. Server returns the requested page or an error message 4. Client displays whatever the server returns 5. Disconnect – drop the connection Summary: retrieving a Web page request page Server Client
The client-server conversation Client Server • OK • Send page or error message • OK • I would like to open a connection • GET <file name> • Display response • Close connection
The HTTP GET command GET /fac/lpress/shortbio.htm HTTP/1.0
Who invented HTTP? Do you know his name?
Formal conversation protocols Describe the protocol governing a conversation with Queen Elizabeth.
Protocols establish standards, facilitating competition Internet Explorer Firefox Safari Opera Chrome What are some other standards that facilitate competition?
A complete page request GET /fac/lpress/shortbio.htm HTTP/1.0 Accept: image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, application/vnd.ms-powerpoint, application/vnd.ms-excel, application/msword, Accept-Language: ko,en-us;q=0.5 User-Agent: Mozilla/4.0 (compatible; MSIE 5.5; Windows NT 5.0) Host: som.csudh.edu Proxy-Connection: Keep-Alive
Self-study questions What would happen if the client program had a bug and sent a request with the command name spelled GETX instead of GET? As a Web user, do you have to be concerned with the details of HTTP? As a programmer writing a Web client, do you have to be concerned with the details of HTTP? As a programmer writing a Web server, do you have to be concerned with the details of HTTP? As a user of a Web service, do you have to be concerned with the details of HTTP?
Resources Definition of the HTTP standard: http://www.w3.org/Protocols/