Basic Network (the Internet) Applications

1. Basic Network (the Internet) Applications Kittiphan Techakittiroj engktc@au.ac.th

2. Agenda • Telnet: using other computer • ftp: transfer files • e-mail: send message • world wide web: information retrieval

3. Telnet • connect to server machine • local machine act as “terminal • text based communication • transmit only “text” • GUI is possible through terminal emulation • simple implementation

4. Telnet What does it need to work? • Host name • hostname.domainname • au1.au.ac.th cwsysf.cwru.edu whitehouse.org • domainname = localname.globalname • purpose, e.g. edu, org, gov, net, mil • country, e.g. th, us, jp, tw, be, tv, to • account or permission • identification = userid+password

5. Telnet Example: most TCP/IP implementation au1% telnet btl4.eng.au.edu Trying 168.120.18.173... Connected to btl4.eng.au.edu. Escape character is '^]'. [SSL not available] Welcome to Linux 2.0.34. btl4 login: admin Password: ******* Linux 2.0.34. Last login: Wed May 5 10:40:17 on ttyp0 from 168.120.18.73. No mail. btl4:~$

6. Telnet Terminal Emulator • improving “user interface” of telnet by terminal Emulator • (Dump Terminal) • ANSI • IBM 3270 • VT100/102 (most popular) • VT240/340 (graphics enhancement)

7. Telnet: Terminal Emulator Example: MS Windows Telnet

8. E-mail • Electronics mail • transfer information from one to the other • act as postal mail • batch processing or off-line communication • text based communication • transmit only “text” • binary (graphics, sound) need encoding

9. E-mail What does it need to work? • access to E-mail system • mail-reader to receive mails • mail-composer to send mails • destination = name+’@’+address • engktc@au.ac.th kxt15@po.cwru.edu • information or data • text • binary need encoding before send and decoding after

10. E-mail Example: UNIX mail (get) hostname:~$ mail Mail version 8.1 6/6/93. Type ? for help. "/var/spool/mail/admin": 5 messages 1 new 1 anderson@meridian.co Mon Mar 8 15:56 77/3907 "OPNET News: LOCKHEED " 2 marlyn@rc.bel.alcate Mon Apr 12 14:49 98/2622 "work = money?" 3 JDCTechTips@sun.com Wed Apr 14 21:02 307/10179 "JDC Tech Tips No." 4 EActor@westnetinc.co Fri Apr 30 00:21 576/42551 "Re: About Your Course" >N 5 admin@btl4.eng.au.ed Wed May 5 11:19 14/424 "test" & 5 Message 5: From admin@btl4.eng.au.edu Wed May 5 11:19:30 1999 Date: Wed, 5 May 1999 11:19:30 +0700 From: Administrator <admin@btl4.eng.au.edu> To: admin@btl4.eng.au.edu Subject: test Cc: engktc@au.ac.th test of E-mail system on "btl4.eng.au.edu" & q Saved 1 message in mbox Held 4 messages in /var/spool/mail/admin hostname:~$

11. E-mail Example: UNIX mail (send) hostname:~$ mail admin@btl4.eng.au.edu Subject: test 2 this is the second test . Cc: hostname:~$ mail Mail version 8.1 6/6/93. Type ? for help. "/var/spool/mail/admin": 2 messages 1 unread 1 EActor@westnetinc.co Fri Apr 30 00:21 576/42551 "Re: About Your Course" >U 2 admin@btl4.eng.au.ed Wed May 5 11:23 14/423 "test 2" & 2 Message 2: From admin@btl4.eng.au.edu Wed May 5 11:23:36 1999 Date: Wed, 5 May 1999 11:23:36 +0700 From: Administrator <admin@btl4.eng.au.edu> To: admin@btl4.eng.au.edu Subject: test 2 this is the second test & q Saved 1 message in mbox Held 1 message in /var/spool/mail/admin hostname:~$

12. E-mail Example: Netscape Messenger (get)

13. E-mail Example: Netscape Messenger (send)

14. FTP • File Transfer Protocol • sharing files via network • transfer information from one to the other • transfer files between remote host (server) and local host (client) • file = information • large or small • text or binary

15. FTP What does it need to work? • Hostname: server location • hostname.domainname • au1.au.ac.th cwsysf.cwru.edu ftp.whitehouse.org • account or permission • identification = userid+password • specific access • public access • file location: directory and name

16. FTP Example: most TCP/IP implementation btl4:~$ ftp btl4.eng.au.edu Connected to btl4.eng.au.edu. 220 btl4.eng.au.edu FTP server (Version wu-2.4.2-academ [BETA-15](1) Wed May 20 1 3:45:04 CDT 1998) ready. Name (btl4.eng.au.edu:admin): admin 331 Password required for admin. Password: ******* 230 User admin logged in. Remote system type is UNIX. Using binary mode to transfer files. ftp> get /etc/hosts ./hosts local: ./hosts remote: /etc/hosts 200 PORT command successful. 150 Opening BINARY mode data connection for /etc/hosts (621 bytes). 226 Transfer complete. 621 bytes received in 0.089 secs (6.8 Kbytes/sec) ftp> quit 221 Goodbye

17. FTP Example: ws_ftp

18. WWW • World Wide Web • huge information systems: (text, graphics, audio, video, etc.) in hyper-text and hyper-media format • allow the use of “telnet”, “ftp”, “e-mail” • need to know only the location • URL://location • http://www.eng.au.edu/ • ftp://ftp.au.ac.th/

19. WWW Example: Lynx GABAC School of Engineering (p1 of 3) Home History ABAC School of Engineering [INLINE] Announcement Academic Society Departments Programs Admission Facilities & Services Welcome to the Faculty of Engineering Assumption University of Thailand Hot News [INLINE] M.Eng. Application period!! click here for more information. [INLINE] Engineering Day is coming click here for more information. A Principle Objective of the Faculty of Engineering is To Develop Engineers who have Academic and Hands On Experience in the Most Recent Technologies. -- press space for next page -- Arrow keys: Up and Down to move. Right to follow a link; Left to go back. H)elp O)ptions P)rint G)o M)ain screen Q)uit /=search [delete]=history list

20. WWW Example: Neoplanet

21. WWW Example: Netscape