1. Internet services & WWW
Sadiq M. Sait, Ph.D
Department of Computer Engineering
King Fahd University of Petroleum and Minerals
Dhahran, Saudi Arabia

2. Internet Services and Applications

3. What really is a Service?
On internet (network of networks), computers communicate with one another. Users of one computer can access services from another.
You can use many methods to communicate with a computer somewhere else on the Internet.
These methods used to communicate are called services because they service your requests.
There are a wide variety of services, and each can give you many kinds of information.
In summary the internet is a:
way to move data
a bunch of protocols

4. Available Services Some most popular services on the Internet are:
Telnet
FTP
WWW
Others (Archie, Wais, Gopher, News and News Groups, Internet Relay Chat, Internet Phone, Video Conferencing, & Internet Collaborative Tools)

5. Available Services (Contd.)
Electronic mail
Telnet: Remote login into computer networks
FTP: File Transfer Protocol for transferring computer files
WWW: World Wide Web
Gopher: Searchable index, selectable index of documents
USENET: Newsgroups with different subjects enable people with common interest to share information
Chat: Real-time communications between people on the Internet

6. Clients and Servers
All that we speak of internet fall into three categories:
Clients
Servers
Content
Software/Hardware that we use to browse the web, send mail, download files, etc are called clients.
Servers respond to clients requests.

7. Internet Applications: FTP and WWW
Client
FTP
server
User
files
Internet
Browser
Helper Applications
Web
Server
Binary
Graphics
Audio
Video

8. E-mail Most popular and widely used internet service.
Has become a de-facto standard of communication within the corporate and beyond.
Works between disparate systems like PC, Unix, Mac, etc.
Latest standards let users attach files (audio, video, animation, etc).
Volume of data transferred is billions of bytes/day.

9. E-mail (Contd.) It is easy to send, read, reply to, and manage.
It is convenient, global, economical and very fast.
It has many advantages over regular methods such as postal service or fax technology.
Studies have shown that recipients are more likely to reply to an message than a written request.
can be read or written at any time, independent of time zones and business hours.

10. E-mail (Contd.) Advantages:
Standard way of communication for corporations
Less interference or interrupts between work
Reply with a number of options
No cost within the environment
Less chance of miscommunication
Can save messages for future retrieval and records
Disadvantages
You need to have a computer and a network connection
Less personal than voice (although now we can also have voice mail, with some extra cost)

11. How works?
Like other internet services is yet another client-server system, called SMTP (simple message transfer protocol).
You use a mail client program to send a message to the post office server (an SMTP server).
The post office server identifies the recipient’s address and send the message through the internet to the mail server that handles mail for each recipient’s address.
The mail server stores the message in the recipient’s mailbox.
The recipient uses an client program to request new messages from the mail server.
The mail server sends the message in the recipient’s mailbox back to the mail client.

12. How e-mail works? (Contd.)
Sender’s
Mail
Client
Post Office Server
(SMTP)
Mail Server (POP3)
Recipient’s Mail Client

13. How e-mail works? (Contd.)
The Internet uses a TCP/IP-family protocol called Simple Mail Transfer Protocol (SMTP) as the standard method for transferring electronic mail.
SMTP handles messages in queues (also called spools).
When a message is sent to SMTP, it places it in an outgoing queue.

14. How e-mail works? (Contd.)
SMTP attempts to forward the message from the queue whenever it connects to remote machines.
Usually, if SMTP cannot forward the message within a given amount of time, it is returned with an error message, or simply dropped.
When a connection is established between two computers that use SMTP, the two systems exchange authentication codes.

15. How e-mail works? (Contd.)
Each system sends a command to the other to identify the first mail message’s sender and provides basic information about the message.
The receiving system returns an acknowledgement, after which the message is transmitted.
SMTP is smart enough to handle multiple destinations for the same message in an efficient manner.

16. Structure of
A typical system, such as the one in a company office, usually consists of a mail server, a post office, and the clients.
The mail system is tied directly to the local area network of the organization.

17. Hotmail, Yahoo Mail, Rocket Mail ….
Hotmail and it’s cousins are all getting to be very popular because
they offer free accounts,
basically use Web-technology
The disadvantage is that you have to
wait longer; frustrating experience if the mail is plenty and the lines are slow--which they are anyway, most of the time!
The major advantage, however,
is access to mail from virtually anywhere they can access the WWW on the Internet
there is privacy, since mail is left on the server

18. Finding an e-mail Address:
Finger and Whois
Finger is a standard utility supplied with the TCP/IP protocol family that lets you determine who is a valid system user and who is logged into a system you have access to.
Finger can be used to find out a person’s username if a mail recipient is logged in on the destination machine.
Finger shows you how long a user has been logged in, where they’re logged in from, and what their login names are.

19. Mailing Lists
A mailing list is a group of addresses that can be reached by sending a message to one address: the list address.
Mail sent to that address is redistributed to all subscribers.
Subscribers can have a discussion by sending messages to the list address (often called posting to the list).
The list of addresses can be maintained by hand or with an automated list server system like Majordomo or ListProcessor.

20. Mailing Lists (Contd.) Mailing lists are good for many things such as:
distributing information from a central source to lots of people
Discussing a project among participants.
Exchanging questions and answers with other users of a product or service, or perhaps company technical-support personnel.
To join just send mail to where listserv is commonly the account through which messages are distributed

21. TELNET Terminal Network Protocol Login to remote computer
Usage of remote computer as if you were a local user
An account on remote computer is required
TELNET use
Remote database access
Remote access to remote customer’s computer for technical support

22. TELNET (Contd.) Need to connect and log in to remote host
Connect using host.domain: telnet vlsi.ccse.kfupm.edu.sa
Account userid must be known
Password is usually required

23. TELNET (Contd.) Weakness
Only console applications can run. No GUI support unless X terminals are used.
Security risk because hackers can trap the IP address of the network.
Least used part of the Web
All ports numbered 80 will have Web sites; likewise all port 23s will be used for telnet, and multi-user games will always be found on 4201, etc.

24. FTP File Transfer Protocol
Allows transfer of any type of file from the remote server to a local computer and vice versa
Two types of FTP
Secure FTP – rarely used because of security issues
Anonymous: widely used
Secure FTP: Login to an account
Access restrictions
Passwords required

25. FTP (Contd.) Anonymous FTP
Provides unrestricted access to files and directories
Examples: free software, publications, press releases, etc.
FTP use
Distribution of software upgrades and new drivers
Access to free information
Access to free software and shareware

26. Anonymous FTP
They are called anonymous because they accept the word “anonymous” as a login name, and your address as the password.
With this kind of service, you can download or upload files without having an account on the machine. Most often used to download files.
If the FTP server isn’t anonymous, when you connect to the server you must provide a user name and password, just as though you were logging in to the machine.
Anonymous FTP servers are one of the major means of distributing software and information across the Internet.

27. Anonymous FTP (Contd.)
FTP servers are fairly straightforward. When a server receives a file request from an FTP client, it sends a copy of that file back to the client.
Other commands instruct the server to send the client a directory of files, or to accept an upload from the client, etc.

28. FTP
A large amount of software, mostly free, is available on anonymous FTP servers for many different types of computer systems.
One of the most frustrating problems with the Internet is the difficulty of finding information such as FTP sites, host resources, sources of information, and so forth.
Most FTP sites don’t have a listing of all their available files, although some do.
However, if you have access to WWW, there are services (both free and fee-based) that provide a WAIS based search from inside a WWW browser, helping in locating information.

29. FTP (contd.) Example FTP actions:
get : Transfer a file from remote host to your computer:
put :Transfer a file from your computer to remote host:
dir or ls : Remote host directory listing
ll or ldir : Local directory listing
chdir or cd :Change remote directory
lcd : Change local directory

30. Archie
The archie service is a collection of resource discovery tools that together provide an electronic directory service for locating information in an Internet environment.
Archie creates a central index of files available on anonymous FTP sites around the Internet.
The Archie servers connect to anonymous FTP sites that agree to participate and download lists of all the files on these sites.
These lists of files are merged into a database, which users can then search

31. Archie (Contd.)
Users can access an archie server either through interactive sessions or through queries sent via electronic mail messages.
The archie server automatically updates the listing information from each site about once a month.
In addition to offering access to anonymous ftp listings, archie also permits access to the “whatis” description database.

32. WAIS
WAIS stands for Wide Area Information Server and is pronounced “ways”.
WAIS searches for words in documents.
The core of the software is an indexer, used to create full-text indexes of files fed to it, and a server that can use those indexes to search for keywords or whole English expressions among the files indexed.

33. Gopher The term Gopher refers to: - A network protocol - A server type
- One of the many Gopher client applications.
Gopher protocol and software allow for browsing information systems so that one doesn’t need to know exactly where the needed information is before looking for it.
You do need to know the address of a Gopher server to get started, after you are there, the server software presents information in a clear, structured, hierarchical list.

34. Gopher (Contd.)
Most Gopher sites have links to others, so after connecting to one, it is quite easy to jump to another.
Gopher’s user interface is very simple.
Since the Gopher service is text-oriented, it performs well over slow links and can be used by people who only have dial-in access to a machine on the internet.

35. Veronica
Veronica is a service that provides a (very large) index of titles of Gopher items from most servers throughout the Internet.
The result of a Veronica search is a set of Gopher items whose titles contain the keyword that the user was searching for.
The Veronica index is accessed via a normal Gopher search item.

36. News & Newsgroups
Network news is another way to take part in a lot of discussions over the internet, yet keeping them organized and separate from your mail.
You don’t have to subscribe to a mailing list, and you won’t receive lots of mail.
The news reader helps you keep everything in order.

37. UseNet
UseNet is a service carried over the Internet that supports newsgroups.
The messages everyone using the UseNet sends to a newsgroup, become available for anyone who accesses the newsgroup.
Newsgroups are organized hierarchically, with the broadest grouping first in the name.

38. Newsgroups There are major news categories like:
comp, news, rec, sci, soc, talk, misc
Servers can also get newsgroups by creating them locally.
Server administrators can create whatever groups they like, corresponding to the interest of the users.

39. News Item A news item is very similar to an electronic mail message.
It has the same general parts as an message; a header and a body.
The body of a news item is the message’s text.
The header tells the news software how to spread the item throughout the Internet.

40. Internet Relay Chat
IRC (Internet Relay Chat) allows you to talk (write) to people from all over the world about a variety of topics, simultaneously and on-line.
It is mostly used as a recreational communication system.
It is again a client-server design.
The client software allows you to connect to the IRC server, which accepts connections from many IRC clients at the same time.
The various IRC servers across the Internet are interconnected.

41. Internet Relay Chat (Contd.)
There are a number of IRC servers running on the Internet, some of them are:
irc.netsys.com irc.caltech.edu irc.indiana.edu csa.bu.edu irc.nada.kth.se
When you connect to an IRC server, you will usually be asked for a port number in addition to the Internet address.
Most of the time, this port number is 6667
Some IRC Terms: Nicknames, IRC Channels

42. Internet Phone
Internet phones let you talk (literally talk, with voice not in writing) to people all over the world, just for the price of your Internet connection.
It demands a reasonably fast machine with support for audio devices.
Internet phones are essentially for point-to-point communications.
The heart of any Internet phone tool is the codec, the software that compresses/decompresses the digitized voice data
Most Internet Phones offer more than just telephony, e.g., voice mail, answering machines, and similar features.

43. Video Conferencing
Internet Video Conferencing offers a low-cost alternative to traditional proprietary systems.
It demands high bandwidths.
It requires a video camera and related hardware card.
Video-conferencing is largely point-to-point.
Only very few packages support true multi-conferencing.

44. Introduction to WWW

45. Introduction to WWW WWW Terminology Web page design and HTML (Basics)
Web Client/Server Software and HTTP
Images, Image maps, forms, and frames
Web authoring and Database integration
Search engines
Dynamic HTML, VRML, etc
Advanced topics and much more

46. Lingo HyperText: Enables linking to places Link(s)
Hyperlinks: Hot spots on which a user can click to access other:
topics (in the same document)
documents, (other HTML files, for e.g.),or
Web sites
URL: Addresses on Internet to which hot spots connect

47. Lingo (contd.) GIF, JPEG, XBM, XPM (picture formats)
Netscape, Mosaic, Iexplorer (browsers)
WebEdit, HoTMetaL, FrontPage (editors/tools)
FTP, TCP/IP, HTTP (protocols)
Applets, J++, javac, Java Engine (Java programming)
xv, clipart, etc (graphics editors)

48. Why Design and for Who? Personal Pages Companies, Organizations
(schools, universities, research centers, etc)
News Networks
Journals
Events (conferences, international games, etc)
Internet/Intranet

49. What in this session? WWW, HTML, and HTTP HTML Document structure
Hyperlinks, Images, Multimedia
Tools for creating HTML
Beyond simple HTML (Advanced tags, dynamic HTML, VRML, etc..)
Other recent technologies (Push technology, e-commerce, search engines..)

50. A Brief overview of HTML?
HTML is a structured language
rules of nesting
All WWW documents are written in HTML
WWW
World Wide Web
Most popular Internet information service

51. Web Usage?
It was estimated that of the 28.8 million people over 16 in the US who have internet access, 11.5 million use the web (1996).

52. World Wide Web Client/Server Architecture
Designed to make it easy for people to share information
Hides complexities of location of documents
Easy to distribute information
Fun to look at

53. World Wide Web Hyperlinks Highlighted words or pictures
Item pointed to may be another document image, movie, sound clip etc

54. Example Visit NYSE city tours NYSE sounds view sights Movie
NY CITY TOURS
NYSE sounds
view sights
Movie
sound audio

55. WWW Browsers Interpret HTTP as well as other protocols
ftp, mailto, telnet, gopher, etc.
Display physical formatted HTML text
in-line images
hyperlinks

56. WWW Browsers Helper Applications
Programs on the user’s computer that can be used to display images, movies, sound, etc. that cannot be displayed on the browser itself
Sound files
Movies (MPEG)
Mail
Other file formats

57. Some Recent Additions Common Gateway Interface ASP
Helper Programs and Plugins
JavaScript and VBScript
etc

58. Why Learn? Why learn HTML or Web Authoring? Everyone is a publisher
The architecture of the Internet allows almost anyone to become an information provider for a world wide audience
WWW documents must be in HTML
To create your own home page you need to know some HTML or Web authoring tool

59. Why learn HTML? Not a must It is very easy to learn and understand
Can use tools to create HTML (FrontPage’98)
Conversion tools can be used to convert existing HTML documents
Example: LaTeX2HTML
Word documents can be saved in HTML
FrameMaker documents too
It is very easy to learn and understand

60. Creating an HTML Page Requirements Focus
Text or HTML Editor to enter TAGS
Graphics editors
Browser (Netscape, Internet Explorer, Lynx, etc.)
Focus
Usable and Eye-catching documents
Images in Web pages
Animation

61. HTML Basics HTML documents contain 3 things Text +TAGS
External Multimedia such as graphics, sound, movies, etc.
Authoring tools insert necessary tags

62. What are Tags? Tags are needed to
Mark text as headings, paragraphs, for formatting, making list etc.
Also for creating hyperlinks, including images, making tables, fill-in forms, frames, etc
Examples: <P>, <A>, <BR>, <HR>, <FONT>, <B>, <TT>, <EM>, <UL>, <IMG>, etc.

63. HTML Document Structure
Basic Structure
<HTML>
<HEAD>
<TITLE> KFUPM </TITLE></HEAD>
<BODY>
….. ….. ……
</BODY>
</HTML>

64. Spinning your HTML Web
To create hot spots (or Anchors) you need two things
URLs (Uniform Resource Locator)
Links
Anchors and Links allow readers to jump from place to place in the document
URL is a fancy way of saying address or location for information on the Internet

65. URL Anatomy & Types Example: Types: Other Protocols (mailto, ftp, etc)
protocol indicator,hostname,directory/filename
Types:
Absolute URLs (also called complete URLs)
Relative URLs (are incomplete URLs)
Other Protocols (mailto, ftp, etc)
ftp://ftp/pub/images/backgrounds/glosbgr.gif

66. Examples http://www.ccse.kfupm.edu.sa/~sadiq/tut.html
<IMAGE SRC= ftp://ftp/pub/images/backgrounds/glosbgr.gif ALIGN = MIDDLE>
<A HREF=“

67. Building Anchors <A>
Components required
The Tag: <A> anchor_name </A>
HREF: Indicates where to jump
NAME: Identifies an internal label
HREF: Lets users jump to either material on the same Web site or to other material on the Internet
NAME: Lets users jump to material within the same document

68. Named Anchor & Basic Links
<A HREF=something>anchor_name </A>
something = #name
name=funny (for example)
something = filename.html[#name]
tutorial.html
something = a Web site, for example
ftp://www/ksu.edu.sa/~ahmed/jokes.html
<H2><A NAME=“funny”> Funny</A></H2>

69. Using Images in Web Pages
Including
Aligning
Using them as links
Making images load more quickly
Using thumbnail images

70. Adding Images Must include them as GIF or JPG graphics
Use graphic editors, scanners, or, borrow
Must use an Image Tag <IMG SRC = "..…”>
ALT=". . . " specifies text to be displayed if image not available
BORDER=# of pixels, controls the thickness of the border
Pictures can be aligned Left, Right, etc.

71. Example of Image Inclusion
<HTML>
<HEAD><TITLE> Biography </TITLE></HEAD>
<BODY>
<H1> Dr. Sadiq M. Saits Biography </H1>
<P><IMG SRC="sadiq.gif"
ALT="Picture of Sadiq Sait " ALIGN=RIGHT>
Picture of Sadiq M. Sait for his biography...</P>
</BODY>
</HTML>

72. Some notes on Images
Loading of images is made faster by telling the browser the size of the image (specified in pixels)
You can link by using images
Can have pictures with no borders
You can use thumbnail images to link to larger images
Making clickable images (image maps)

73. Pictures as Links <P> <A HREF="saitbio.html">
<IMG SRC="sadiq.gif"
ALT="Picture of Sadiq Sait" ALIGN=RIGHT
HSPACE=20 HEIGHT=100 WIDTH=50
BORDER=0>
</A>
Sadiq M. Sait was born in </P>

74. Using Thumbnails <P> <A HREF="sadiqbig.gif">
<IMG SRC="sadiqthumbnail.gif"
ALT="Picture of Sadiq Sait">
</A> Thumbnail of Sait’s picture….

75. Defining the map
Tells which area readers may click and what link to follow
<MAP>
NAME= “ “ gives the map a name
<AREA> specifies the shape of a ‘hot spot’
COORDS=“x1,y1,x2,y2,…”
HREF=“URL”
SHAPE= “…” specifies type of shape as RECT, CIRC, POLYGON, etc.

76. Other Attributes Choosing Colors
Background
Links (link, alink, vlink)
Text
Colors can be chosen for tables, background etc.
RGB concept (#FFFFFF=white)
Choosing background (using images, .gif files)

77. Beyond Simple HTML Tables Forms Frames Simple animation
Inclusion of Java Applets
JavaScript and CGI programs

78. Some More Tags CENTER, BLINK, HR, APPLET <FORM> <TABLE>
SELECT, OPTION, TEXTAREA
<TABLE>
TR, TH, TD, CAPTION
FRAME
FRAMESET
And many more….

79. Tables in HTML Caption Alignment and Width Table Header <TH>
Table Data <TD>
Table Rows <TR>
Color (of cells)
Border or not (and width)

80. Tables (example) <TABLE BORDER=10
ALIGN=ABSCENTER bgcolor=#68d1cc>
<CAPTION><H3> This is a table with a border</H3> </CAPTION>
<TR> <TH> <TH>Male <TH>Female <TR> <TH>Pop <TD>0.49<TD>0.51 <TR> <TH>Wealth <TD> 0.9<TD> 0.1
</TABLE>

81. Forms in HTML What are they used for Features
Surveys
Collect addresses of visitors to your Homepage
Allow people to register for something
Features
Submitted by mail
Security (Passwords)
Checkboxes and Radio buttons
Area for Text and Comments
Require a CGI program on server to process data coming from the form submission

82. Frames SRC: URL of documents to be displayed
NAME: so this frame can be targeted by links in other documents
Physical dimensions: Height, width etc.
Other features: Scrolling, Resizing, etc.
They are a complete HTML document or a page

83. Spicing up your Web Page
Some HTML commands and Tricks
BLINK tag, etc
Animation (GIF animation) and Sound
Using Java Applets
Scripting (JavaScript/VBScript)
Videostreaming

84. Java Applet inclusion Compile the Java code (e.g., use javac)
example: javac Blinker
Creates file with extension .class,
example Blinker.class
Use the tags <APPLET> … </APPLET>
Specify parameters such as speed, color (for background and text, etc.)

85. Java Applet Inclusion (contd.)
<applet code=“Blink.class” width=300 height=30>
<param name=lbl value = “SADIQ M. SAIT,”>
<param name=speed value=“6”>
</applet>

86. Java Applet Inclusion (contd.)
<applet code=“ticker.class” width=280 height=30>
<param name=msg value = “Welcome to the tutorial on Web page design and HTML!” >
<param name=“shco” value=“210, 210,210”>
<param name=“speed” value=“9”>
<param name=“bgco” value=“255,255,255”>
<param name=“txtco” value=“255,0,0”>
</applet>

87. Other Topics cgi-bin (common gateway interface) Executable: Example
<!--#exec cgi=“/cgi-bin/counter”--> people visited this page.
Helper programs
to send mail
run audio/video applications
etc

88. Searching On the internet we can Search engines using the Web
search for a file using Archie
Find an address
Internet White Pages (internic keeps records)
Finding a gopher site
etc
Search engines using the Web

89. Search Engines Tools to discover Web resources on the internet
Help in locating information
They act as an agent between publishers and users

90. Other & Recent Technologies
Authoring Tools
VRML, Dynamic HTML, ASPs, etc
Video Streaming
Push Technology
Data-Base Integration
Search Engines
E-Commerce

91. Finally….
Summary
Demo