# HyperText Transfer Protocol

# HyperText Transfer Protocol Simulator

## Protocol Description

HTTP (Hypertext Transfer Protocol) is familiar as the mechanism for delivering web pages. HTTP operates over TCP (Transmission Control Protocol) in client-server mode for reliable transfer of data. URLs (Uniform Resource Locators) and information contents are represented symbolically in the simulation (URLn, DATAn). The protocol simulation deals with the main commands:

- GET: get data for URL
- HEAD: get header for URL
- POST: append data to URL
- xPUT: send data to URL

The simulation supports a limited range of response codes:

- 200 OK: the command completed successfully
- 301 MOVED: the requested URL has moved to another location
- 400 ERROR: the command encountered an error (not explicit in the simulation)

The protocol simulation shows a time-sequence diagram with client and server protocol entities, and a communications medium that carries messages. The client sends a one of the above commands and a URL. The server makes one of the above replies. Since the medium is assumed to be reliable, messages are never lost (though they may be delayed).

## Protocol Parameters

This simulation has no parameters.

## Protocol Simulation

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