1 / 9

Overview of Application Layer Protocols: HTTP, SMTP, FTP, and Telnet

This document provides a comprehensive overview of key application layer protocols, including HTTP, SMTP, FTP, and Telnet. It discusses how the application layer accepts commands from users, prepares messages for the network layer, and supports various functions such as email communication, file transfers, and web browsing. The usage of these protocols in different scenarios—including HTML content handling and remote command execution—is explored, shedding light on their significance in enhancing network functionality and user interaction.

amaris
Télécharger la présentation

Overview of Application Layer Protocols: HTTP, SMTP, FTP, and Telnet

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Application layer • Accepts commands from the user • Prepares messages for the network layer • Data • Destination

  2. World wide web (HTTP) • GET http://www.eit.ac.nz/index.html HTTP/1.1 • Date: Mon 06 Sep 1999 09:49:00 NZSTUser-Agent: Lynx/2.0From: corrin.lakeland@eit.ac.nzReferer: http://www.yahoo.com/results.html

  3. World wide web -output • HTTP/1.1 00 OKDate: Mon 06 Sep 1999 09:52:00 NZSTServer: Apache/1.3Location: http://www.eit.ac.nz/index.htmlContent-Type: text/html • <HTML><HEAD><TITLE>…</TITLE></HEAD><BODY>…</BODY></HTML>

  4. Mail (SMTP) • Should also know about: POP, IMAP • MAIL FROM: <corrin.lakeland@xtra.co.nz>RCPT TO: <webmaster@eit.ac.nz>DATA

  5. Mail body • From: Corrin Lakeland <corrin.lakeland@xtra.co.nz>To: Herbert Halasz <webmaster@eit.ac.nz>Date: Mon 06 Sep 1999 09:49:00 NZSTSubject: Re: Installing SSL in ports other than 443X-Mailer: KmailX-Precedence: NormalPath: eit.ac.nz!telstra.co.nz!gateway…QUIT

  6. File transfer (FTP) • USER: lakeland or anonymous • PASS: secret or lakeland@cs.otago.ac.nz • DIR, PORT, … • Cannot be done over telnet

  7. Telnet • Remote commands are executed and output sent back. • Ideal for accessing crays, connecting to libraries, etc. • Non graphical (X for graphics)

  8. News (NNTP) • Netiquitte • Being replaced by mailing lists

  9. Groupware • Tools to help groups work together • Different facilities for: • Same time vs. Different time • Same place vs. Different place • Many possible facilities • Document based • Video conferencing • Group support systems

More Related