The document provides information about networking and internet technologies. It discusses computer networks and how they allow sharing of information, data, programs and resources. This reduces costs. Network topologies like star, bus, ring and tree are covered. Different types of network cabling including UTP, coaxial, fiber optic and wireless are described. Components of a network like servers, clients and networking devices are explained. Concepts like packet switching, peer to peer networks and protocols are also summarized.

1. I.T. for Management
Chapter 5
Networking/Internet & Web technologies

2. Networking
• The Computer Network is nothing but a set of
computers connected to each other, mainly for
Sharing information, data, programs &
resources.
• Networking reduces the cost of doing
business since resources are utilized to
optimum extent.
• The evolution of newer business models such as
the ITES/BPO,the offshore Software etc are an
outcome of the Networks be it in Telephony or in
terms of computer networks.

3. Networking
• Benefits
• Interaction & communication between various
people at locations & perhaps using different
types of hardware& software different
• Sharing of Data so that there is consistency of
data
• Sharing of expensive devices such as printers
• Created newer and previously unthinkable ways
of doing business such as telecom,BPO etc.

4. Networking
• Broad categories of networking are
LAN, WAN, MAN
Cu Cable, Fiber Cable, Wireless
TCP/IP, HTTP Protocols
Star, Bus, Ring Topology
Packet Switching/Network switching
Peer to Peer Network

5. Network Topologies
What is a Topology?
The physical topology of a network refers
to the configuration of cables, computers,
and other peripherals.
Physical topology should not be confused
with logical topology which is the method
used to pass information between
workstations

6. Network Topologies
Main Types of Physical Topologies
The following sections discuss the physical
topologies used in networks and other related
topics.
• Linear Bus
• Star
• Star-Wired Ring
• Tree

7. Network Topologies
Linear Bus
A linear bus topology consists of a main run of
cable with a terminator at each end (See fig. 1).
All nodes (file server, workstations, and
peripherals) are connected to the linear cable.
Ethernet and LocalTalk networks use a linear
bus topology.

8. Network Topologies
dvantages of a Linear Bus Topology Easy to
connect a computer or peripheral to a linear bus.
Requires less cable length than a star
topology.
isadvantages of a Linear Bus Topology
Entire network shuts down if there is a break
in the main cable.
Terminators are required at both ends of the
backbone cable.
Diffi lt t id tif th bl if th ti

9. Network Topologies
Star
A star topology is designed with each node (file server,
workstations, and peripherals) connected directly to a central
network hub or concentrator (See fig. 2).
Data on a star network passes through the hub or
concentrator before continuing to its destination.
The hub or concentrator manages and controls all
functions of the network. It also acts as a repeater for the
data flow.
This configuration is common with twisted pair cable;
however, it can also be used with coaxial cable or fiber optic
cable.

10. Network Topologies
dvantages of a Star Topology
Easy to install and wire.
No disruptions to the
network then connecting or
removing devices.
isadvantages of a Star Topology
Easy to detect faults and to
remove parts.
Requires more cable length than a
linear topology.
If the hub or concentrator fails,
nodes attached are disabled.
More expensive than linear bus

11. Network Topologies
Tree
A tree topology combines
characteristics of linear bus and
star topologies. It consists of
groups of star-configured
workstations connected to a
linear bus backbone cable (See
fig. 4). Tree topologies allow
for the expansion of an existing
network, and enable schools to
configure a network to meet
their needs.

12. Components of a Network
• The Computers are connected to the medium with the
help of network interface cards(NIC)
• One of the computers on the network is designed as
controller usually called as Server
• Sever usually maintains vital information about network,
• Holds shared software& services
• Monitors facilities so that problems on network can be
detected& corrected
• It act as intelligent device which routes the message to
the appropriate path

13. Networking Devices
• Common basic network devices:
Gateway: device sitting at a network node for
interfacing with another network that uses different
protocols. Works on OSI layers 4 to 7.
Router: a specialized network device that
determines the next network point to which to
forward a data packet toward its destination. Unlike
a gateway, it cannot interface different protocols.
Works on OSI layer 3.
Bridge: a device that connects multiple network
segments along the data link layer. Works on OSI
layer 2.

14. Networking Devices
Switch: a device that allocates traffic from one network
segment to certain lines (intended destination(s)) which
connect the segment to another network segment. So
unlike a hub a switch splits the network traffic and sends
it to different destinations rather than to all systems on
the network. Works on OSI layer 2.
Hub: connects multiple Ethernet segments together
making them act as a single segment. When using a
hub, every attached device shares the same broadcast
domain and the same collision domain. Therefore, only
one computer connected to the hub is able to transmit at
a time.

15. Networking Devices
Depending on the network topology, the hub
provides a basic level 1 OSI model connection
among the network objects (workstations,
servers, etc). It provides bandwidth which is
shared among all the objects, compared to
switches, which provide a dedicated connection
between individual nodes. Works on OSI layer 1.
Repeater: device to amplify or regenerate digital
signals received while setting them from one
part of a network into another. Works on OSI
layer 1.

16. Network Cabling
What is Network Cabling?
Cable is the medium through which information
usually moves from one network device to
another. There are several types of cable which
are commonly used with LANs. In some cases, a
network will utilize only one type of cable, other
networks will use a variety of cable types. The
type of cable chosen for a network is related to
the network's topology, protocol, and size.
Understanding the characteristics of different
types of cable and how they relate to other
aspects of a network is necessary for the
development of a successful network

17. Network Cabling
Unshielded Twisted Pair (UTP) Cable
Twisted pair cabling comes in two varieties:
shielded and unshielded. Unshielded twisted
pair (UTP) is the most popular and is generally
the best option for school networks
(See fig. 1).

18. Network Cabling
Coaxial Cable
Coaxial cabling has a single copper
conductor at its center. A plastic layer
provides insulation between the center
conductor and a braided metal shield (See
fig. 3). The metal shield helps to block any
outside interference from fluorescent lights,
motors, and other computers.

19. Network Cabling
Fiber Optic Cable
Fiber optic cabling consists of a center glass core
surrounded by several layers of protective materials
(See fig. 5).
It transmits light rather than electronic signals
eliminating the problem of electrical interference. This
makes it ideal for certain environments that contain a
large amount of electrical interference. It has also made
it the standard for connecting networks between
buildings, due to its immunity to the effects of moisture
and lighting.

20. Network Cabling
Maximum
Specificatio Cable Type
length
n
10BaseT Unshielded Twisted 100 meters
Pair
10Base2 Thin Coaxial 185 meters
10Base5 Thick Coaxial 500 meters
10BaseF Fiber Optic 2000 meters
100BaseT Unshielded Twisted
Pair
100 meters
100BaseT Unshielded Twisted 220 meters
X Pair

21. Network Cabling
Wireless LANs
Not all networks are connected with cabling; some networks
are wireless. Wireless LANs use high frequency radio
signals, infrared light beams, or lasers to communicate
between the workstations and the file server or hubs. Each
workstation and file server on a wireless network has some
sort of transceiver/antenna to send and receive the data.
Information is relayed between transceivers as if they were
physically connected. For longer distance, wireless
communications can also take place through cellular
telephone technology, microwave transmission, or by
satellite.

22. Network Cabling
Wireless LANs
Wireless networks are great for allowing laptop
computers or remote computers to connect to the
LAN. Wireless networks are also beneficial in older
buildings where it may be difficult or impossible to
install cables.

23. How do Networks Work
Once the physical connection between computers are
established ,computers can send messages to each other
A computer wishing to communicate with another
needs to do what is known as a “hand Shaking”
All these rules for communication is called protocols
There are various protocols at various levels of software
In practice there are different layers of software each
performing different functions
There is a well known international model defined by
International Standards Organization

24. How do Networks Work
OSI Model
Data unit Layer Function
Application Network process to application
Data Presentation Data representation and encryption
Host
layers
Session Inter host communication
Segments Transport End-to-end connections and
reliability (TCP)
Packets Network Path determination and logical
addressing (IP)
Media
Frames Data link Physical addressing (MAC & LLC)
layers
Bits Physical Media, signal and binary
transmission

25. How do Networks Work
Packet switching, in computer networking and
telecommunications, is the communications paradigm in
which packets (units of information carriage) are routed
between nodes over data links shared with other traffic.
This contrasts with the other principal paradigm, circuit
switching, which sets up a dedicated connection between the
two nodes for their exclusive use for the duration of the
communication. Packet switching is used to optimize the use
of the bandwidth available in a network, to minimize the
transmission latency (i.e. the time it takes for data to pass
across the network), and to increase robustness of
communication.

26. How do Networks Work
Packet routing
Packets are routed to their destination as determined by a
routing algorithm. The routing algorithm can create paths
based on various metrics and desirable qualities of the
routing path. For example, low latency may be of paramount
concern and everything else is secondary, or a minimum
hop count.
It's also entirely possible to have to weigh the various
metrics against each other. For example, reducing the hop
count could increase the latency to an unacceptable limit
and some kind of balance would need to be found. For
multi-parameter optimization, some form of optimization
may be needed.

27. How do Networks Work
A peer-to-peer system is a distributed system whose
component nodes participate in similar roles, and are
therefore peers to each other. Peer-to-peer can be
viewed as decentralized network architecture. In
contrast, a client-server architecture implies a sharp
distinction between the clients which request and
consume services, and servers which provide services.
Even though the nodes have similar roles, there may
still be some structure to the peer-to-peer system, and it
usually possesses some degree of self-organization
where each node finds its peers and helps maintain the
system structure. ……. Cont

28. How do Networks Work
This makes a peer-to-peer network node more complex than a
client in client-server system. The main benefits of peer-to-peer
system are scalability, fault-tolerance, and the lack of resource
bottlenecks in servers.
The peer-to-peer concept is related to Distributed computing and
Swarm intelligence, but differs from them in that peer-to-peer
nodes usually serve their own needs acting as Intelligent agents,
instead of performing a collective function as a group.
Recently, the concept has achieved recognition in the general
public in the context of peer-to-peer file sharing which is one
application of peer-to-peer networks.

29. Wi-Fi in campus
For computers to use the wireless facility requires
2 things
Each computer must be fitted with wireless
card.most Laptops tend to have this facility
The server would send information thru a LAN.A
wireless access point which is a special deviceis
also connected to the LAN
This device converts the signals received from the
LAN & broadcasts them into signal suitable
for LAN

30. Wi-Fi in campus
Any products tested and approved as "Wi-Fi Certified" (a
registered trademark) by the Wi-Fi Alliance are certified as
interoperable with each other, even if they are from different
manufacturers. A user with a "Wi-Fi Certified" product can
use any brand of access point with any other brand of client
hardware that also is certified. Typically, however, any Wi-Fi
product using the same radio frequency (for example, 2.4GHz
for 802.11b or 11g, 5GHz for 802.11a) will work with any
other, even if not "Wi-Fi Certified."
.

31. Wi-Fi in campus
The Advantages of Wi-Fi in a campus
It can be installed very easily& quickly no civil
work no cable laying, antenna can be deployed in a
single day
User using laptops PDA can move devices to
any locations without getting disconnected
Thus it provides access anywhere,anytime
within the campus
This can increase productivity of the work force

32. Plain Old Telephone systems
Short for plain old telephone service, which refers to the
standard telephone service that most homes use. In contrast,
telephone services based on high-speed, digital
communications lines, such as ISDN and FDDI, are not
POTS.
The main distinctions between POTS and non-POTS
services are speed and bandwidth. POTS is generally
restricted to about 52 Kbps (52,000 bits per second).
The POTS network is also called the public switched
telephone network (PSTN).

33. Plain Old Telephone systems
Plain old telephone service, or POTS, is a term which
describes the voice-grade telephone service that remains the
basic form of residential and small business service
connection to the telephone network nearly everywhere in
the world.
The name is a reflection of the telephone service still
available after the advent of more advanced forms of
telephony such as ISDN, mobile phones and VoIP. It has
been available almost since the introduction of the public
telephone system in the late 19th century, in a form mostly
unchanged to the normal user despite the introduction of
Touch-Tone dialing, electronic telephone exchanges and
fiber-optic communication into the public switched
telephone network (PSTN).

34. VSAT based network
A 2.5m parabolic dish antenna for bidirectional
Satellite Internet Access.
A Very Small Aperture Terminal (VSAT), is a 2-
way satellite ground station with a dish antenna that
is smaller than 3 meters. VSATs are most
commonly used to transmit credit card or RFID
data for point of sale transactions, and for the
provision of Satellite Internet access to remote
locations.

35. VSAT Advantages
The advances of computer technology have changed the satellite business
situation of FSS (Fixed satellite services). This FSS satellite system has a
huge capacity with relatively low price system including prices for
providing VSATs terminal. This tendency causes the FSS system become
a very interesting business. Nowadays, the regulation of satellite services
goes to the subscribers using VSAT terminal. These FSS satellite systems
provide various applications for subscribers. These applications are not
only limited in phone conversation, faximile, TV broadcast or high speed
communication services, but also for new services such as direct to home
(DTH), internet access, video conferencing, Satellite News Gathering
(SNG), frame relay, Digital Audio Broadcasting (DAB) and others.
Basically, these systems are applicable for providing various excellent
quality services, because they create efficient communication system,
both for home dwellers and business people.

36. ISDN
Integrated Services Digital Network (ISDN) is a circuit-
switched telephone network system, designed to allow
digital transmission of voice and data over ordinary
telephone copper wires, resulting in better quality and
higher speeds than that available with the PSTN system.
More broadly, ISDN is a set of protocols for establishing
and breaking circuit switched connections, and for
advanced call features for the user.
In a videoconference, ISDN provides simultaneous voice,
video, and text transmission between individual desktop
videoconferencing systems and group (room)
videoconferencing systems.

37. Advantages of ISDN
The purpose of the ISDN is to provide fully
integrated digital services to the users.
These services fall under three categories: bearer
services, supplementary services and teleservices.
Being digital they carry signals without much
distortion
It can carry all types of signals voice data &
multimedia
ISDN is typically used for vedio conferance

38. Internet
The Internet is the worldwide, publicly accessible
network of interconnected computer networks that
transmit data by packet switching using the
standard Internet Protocol (IP). It is a "network of
networks" that consists of millions of smaller
domestic, academic, business, and government
networks, which together carry various information
and services, such as electronic mail, online chat,
file transfer, and the interlinked Web pages and
other documents of the World Wide Web.

39. Internet Protocols
•IP (Internet Protocol), which defines the datagrams or packets that
carry blocks of data from one node to another. The vast majority of
today's Internet uses version four of the IP protocol (i.e. IPv4), and
although IPv6 is standardized, it exists only as "islands" of
connectivity, and there are many ISPs without any IPv6 connectivity.
[1]
•Next come TCP (Transmission Control Protocol), UDP (User
Datagram Protocol), and ICMP (Internet Control Message Protocol) -
the protocols by which data is transmitted. TCP makes a virtual
'connection', which gives some level of guarantee of reliability. UDP is
a best-effort, connectionless transport, in which data packets that are
lost in transit will not be re-sent. ICMP is connectionless, it is used for
control and signaling purposes.
•On top comes the application protocol. This defines the specific
messages and data formats sent and understood by the applications
running at each end of the communication.

40. How does a dial up user get
connected to internet
The dial up users computer is not a host on the
internet.He has to connect to the internet service
provider such as VSNL
After authenticating the user,VSNL server would
assign a temporary IP number from a shared pool of
IP numbers
Once your machine gets a temporary IP address
and is connected to internet via VSNL servers your
machine becomes a host on the internet
…..Cont

41. How does a dial up user get
connected to internet
Hence someone wishes to chat with you can type
your temporary IP number & access your machine
Once you log out of internet the IP number is de
allocated & is available in the share pool with the
service provider
The Worldwide web is the most popular
application on the internet
Hypertext Mark up language (HTML) provides a
standard tag which identifies each block within
document

42. Web Server
The term Web server can mean one of two things:
1.A computer that is responsible for accepting
HTTP requests from clients, which are known as
Web browsers, and serving them HTTP
responses along with optional data contents,
which usually are Web pages such as HTML
documents and linked objects (images, etc.).
2.A computer program that provides the
functionality described in the first sense of the
term. …… Cont

43. Web Server
Although Web server programs differ in detail, they all
share some basic common features.
1.HTTP: every Web server program operates by
accepting HTTP requests from the network, and
providing an HTTP response to the requester. The HTTP
response typically consists of an HTML document, but
can also be a raw text file, an image, or some other type
of document; if something bad is found in client request
or while trying to serve the request, a Web server has to
send an error response which may include some custom
HTML or text messages to better explain the problem to
end users.
Logging: usually Web servers have also the capability of
logging some detailed information, about client requests and
server responses, to log files; this allows the Webmaster to
collect statistics by running log analyzers on log files.

44. Web Server
The inside/rear of a Dell PowerEdge web server, which is using the
Apache web server software

45. Web Server
The web server & documents are located by a
user with the help of uniform resource
locator(URL) which is like web address
The user types the URL on the search bar
URL is converted into IP address of the web
server and the browser request is sent to the web
server
The web server locates the document based on
the registration which information which it has
about the document It sends document across
internet to the IP address

46. Domain Names
• The term domain name has multiple related
meanings:
A name that identifies a computer or computers
on the internet. These names appear as a
component of a Web site's URL, e.g.
www.wikipedia.org. This type of domain name is
also called a hostname.
The product that Domain name registrars
provide to their customers. These names are
often called registered domain names.

47. Domain Names
They are sometimes colloquially (and incorrectly)
referred to by marketers as "web addresses".
Names used for other purposes in the Domain
Name System (DNS), for example the special
name which follows the @ sign in an email
address, or the Top-level domains like .com, or
the names used by the Session Initiation
Protocol (VoIP), or DomainKeys.

48. Domain Names
• The following example illustrates the
difference between a URL (Uniform
Resource Locator) and a domain name:
• URL: http://www.example.net/index.html
• Domain name: www.example.net
• Registered domain name: example.net
……cont

49. Domain Names
As a general rule, the IP address and the server
name are interchangeable. For most Internet
services, the server will not have any way to
know which was used. However, the explosion
of interest in the Web means that there are far
more Web sites than servers. To accommodate
this, the hypertext transfer protocol (HTTP)
specifies that the client tells the server which
name is being used. This way, one server with
one IP address can provide different sites for
different domain names.

50. HTTP
Short for Hyper Text Transfer Protocol, the
underlying protocol used by the World Wide Web.
HTTP defines how messages are formatted and
transmitted, and what actions Web servers and
browsers should take in response to various
commands. For example, when you enter a URL in
your browser, this actually sends an HTTP
command to the Web server directing it to fetch and
transmit the requested Web page.

51. HTTP
The other main standard that controls how the
World Wide Web works is HTML, which covers
how Web pages are formatted and displayed.
HTTP is called a stateless protocol because each
command is executed independently, without any
knowledge of the commands that came before it.
This is the main reason that it is difficult to
implement Web sites that react intelligently to user
input. This shortcoming of HTTP is being addressed
in a number of new technologies, including
ActiveX, Java, JavaScript and cookies.

52. Cookies
The main purpose of cookies is to identify users and possibly
prepare customized Web pages for them.
When you enter a Web site using cookies, you may be asked
to fill out a form providing such information as your name
and interests.
This information is packaged into a cookie and sent to your
Web browser which stores it for later use.
The next time you go to the same Web site, your browser
will send the cookie to the Web server.

53. Cookies
The server can use this information to present you with
custom Web pages. So, for example, instead of seeing just a
generic welcome page you might see a welcome page with
your name on it.
The name cookie derives from UNIX objects called magic
cookies.
These are tokens that are attached to a user or program and
change depending on the areas entered by the user or
program

54. Websites
A website (or Web site) is a collection of web
pages, images, videos and other digital assets and
hosted on a particular domain or subdomain on the
World Wide Web.
A web page is a document, typically written in
HTML, that is almost always accessible via HTTP,
a protocol that transfers information from the
website's server to display in the user's web
browser.

55. Websites
All publicly accessible websites are seen
collectively as constituting the "World Wide Web".
The pages of websites can usually be accessed from
a common root URL called the homepage, and
usually reside on the same physical server. The
URLs of the pages organize them into a hierarchy,
although the hyperlinks between them control how
the reader perceives the overall structure and how
the traffic flows between the different parts of the
sites.

56. Websites
Some websites require a subscription to access
some or all of their content. Examples of
subscription sites include many business sites, parts
of many news sites, gaming sites, message boards,
Web-based e-mail services, and sites providing
real-time stock market data.
As of March 2007 there are over 110 million
websites in total on the world wide web.

57. Websites
History
The first on-line website appeared in 1991. On 30 April
1993, CERN announced that the World Wide Web would be
free to anyone..
Overview
Organized by function a website may be
•a personal website
•a business website
•a government website or
•a non-profit organization website.

58. Websites
Websites are written in, or dynamically converted
to, HTML (Hyper Text Markup Language) and are
accessed using a software program called a Web
browser, also known as an HTTP client. Web pages
can be viewed or otherwise accessed from a range of
computer based and Internet enabled devices of
various sizes, including desktop computers, laptop
computers, PDAs and cell phones.

59. Websites
A website is hosted on a computer system known as
a web server, also called an HTTP server, and these
terms can also refer to the software that runs on
these system and that retrieves and delivers the Web
pages in response to requests from the website users.
Apache is the most commonly used Web server
software

60. Websites
A static website, is one that has web pages stored on
the server in the same form as the user will view
them. They are edited using three broad categories of
software:
•Text editors. such as Notepad or TextEdit, where
the HTML is manipulated directly within the
editor program
•WYSIWYG editors. such as Microsoft
FrontPage and Macromedia Dreamweaver, where
the site is edited using a GUI interface and the
underlying HTML is generated automatically by
the editor software

61. Websites
Template-based editors, such as Rapidweaver and
iWeb, which allow users to quickly create and
upload websites to a web server without having to
know anything about HTML, as they just pick a
suitable template from a palette and add pictures and
text to it in a DTP-like fashion without ever having
to see any HTML code.
A dynamic website is one that has frequently
changing information or collates information on the
hop each time a page is requested. For example, it
would call various bits of information from a
database and put them together in a pre-defined
format to present the reader with a coherent page.

62. Websites
It interacts with users in a variety of ways including
by reading cookies recognizing users' previous
history, session variables, server side variables etc.,
or by using direct interaction (form elements,
mouseovers, etc.). A A site can display the current
state of a dialogue between users, monitor a
changing situation, or provide information in some
way personalized to the requirements of the
individual user.

63. Websites
Suppliers can now view
The requirement of the customer
Bid for the requirement
Received a confirmed order from the customer
via the Website
Updates the information on deliveries sent to the
customer
Get acknowledgement & receive payment for
deliveries

64. Types of websites
There are many varieties of Web sites, each specialising in a
particular type of content or use, and they may be arbitrarily
classified in any number of ways. A few such classifications
might include:[original research?]
Affiliate: enabled portal that renders not only its custom CMS
but also syndicated content from other content providers for an
agreed fee. There are usually three relationship tiers. Affiliate
Agencies (e.g., Commission Junction), Advertisers (e.g., Ebay)
and consumer (e.g., Yahoo).
Archive site: used to preserve valuable electronic content
threatened with extinction. Two examples are: Internet Archive,
which since 1996 has preserved billions of old (and new) Web
pages; and Google Groups, which in early 2005 was archiving
over 845,000,000 messages posted to Usenet news/discussion
groups.

65. Types of websites
Blog (or web log) site: sites generally used to post online
diaries which may include discussion forums (e.g., blogger,
Xanga).
Corporate website: used to provide background information
about a business, organization, or service.
Commerce site or eCommerce site: for purchasing goods, such
as Amazon.com.
Community site: a site where persons with similar interests
communicate with each other, usually by chat or message
boards, such as MySpace.
Database site: a site whose main use is the search and display
of a specific database's content such as the Internet Movie
Database or the Political Graveyard.
Development site: a site whose purpose is to provide
information and resources related to software development,
Web design and the like.

66. Types of websites
Types of websites
Download site: strictly used for downloading electronic content,
such as software, game demos or computer wallpaper.
Employment site: allows employers to post job requirements for
a position or positions and prospective employees to fill an
application.
Game site: a site that is itself a game or "playground" where
many people come to play, such as MSN Games and
Pogo.com.
Geodomain refers to domain names that are the same as those
of geographic entities, such as cities and countries. For
example, Richmond.com is the geodomain for Richmond,
Virginia.
Gripe site: a site devoted to the critique of a person, place,
corporation, government, or institution.
Humor site: satirizes, parodies or otherwise exists solely to
amuse

67. Types of Website
Information site: contains content that is intended to inform visitors,
but not necessarily for commercial purposes, such as:
RateMyProfessors.com, Free Internet Lexicon and Encyclopedia.
Most government, educational and non-profit institutions have an
informational site.
Java applet site: contains software to run over the Web as a Web
application.
Mirror (computing) site: A complete reproduction of a website.
News site: similar to an information site, but dedicated to dispensing
news and commentary.
Personal homepage: run by an individual or a small group (such as
a family) that contains information or any content that the individual
wishes to include.

68. Types of website
Phish site: a website created to fraudulently acquire sensitive
information, such as passwords and credit card details, by
masquerading as a trustworthy person or business (such as Social
Security Administration, PayPal) in an electronic communication.
(see Phishing).
Political site: A site on which people may voice political views.
Pornography (porn) site: a site that shows pornographic images and
videos.
Rating site: A site on which people can praise or disparage what is
featured (e.g. ratemycar.com).
Review site: A site on which people can post reviews for products or
services.
Search engine site: a site that provides general information and is
intended as a gateway or lookup for other sites. A pure example is
Google, and the most widely known extended type is Yahoo!.

69. Email
An E-mail Message
According to Darwin Magazine: Prime
Movers, the first e-mail message was sent in
1971 by an engineer named Ray Tomlinson.
Prior to this, you could only send messages
to users on a single machine. Tomlinson's
breakthrough was the ability to send
messages to other machines on the Internet,
using the @ sign to designate the receiving
machine.

70. Email
An e-mail message has always been nothing more
than a simple text message -- a piece of text
sent to a recipient. In the beginning and even
today, e-mail messages tend to be short pieces
of text, although the ability to add attachments
now makes many e-mail messages quite long.
Even with attachments, however, e-mail
messages continue to be text messages -- we'll
see why when we get to the section on
attachments.

71. Email
The Real E-mail System
For the vast majority of people right now, the
real e-mail system consists of two different
servers running on a server machine. One is
called the SMTP server, where SMTP
stands for Simple Mail Transfer Protocol.
The SMTP server handles outgoing mail.
The other is either a POP3 server or an
IMAP server, both of which handle incoming
mail. POP stands for Post Office Protocol,
and IMAP stands for Internet Mail Access
Protocol.

72. Email
A typical e-mail server looks like this:
The SMTP server listens on well-known port number 25,
POP3 listens on port 110 and IMAP uses port 143 (see How
Web Servers Work for details on ports).

73. Email
The SMTP Server
Whenever you send a piece of e-mail, your e-mail client
interacts with the SMTP server to handle the sending. The
SMTP server on your host may have conversations with
other SMTP servers to actually deliver the e-mail.

74. Email
Email is very effective means of communication
It is fast & asynchronous
Email is quite often a source of spreading a
viruses
Email created new opportunities for marketing
Cost remains same even if number of recipients
increase

75. SPAM
The term "spam" is Internet slang that refers to
unsolicited commercial email (UCE) or unsolicited
bulk email (UBE). Some people refer to this kind of
communication as junk email to equate it with the
paper junk mail that comes through the US Mail.
Unsolicited email is email that you did not request;
it most often contains advertisements for services or
products. There are very few reputable marketers
using UCE to advertise goods and services.

76. SPAM
The most commonly seen spam includes the
following:
· Phishing scams, a very popular and
dangerous form of email fraud
· Foreign bank scams or advance fee fraud
schemes
· Pyramid schemes, including multilevel
marketing (MLM)
· Other "Get Rich Quick" or "Make Money
Fast" (MMF) schemes
· Quack health products and remedies
….Cont

77. SPAM
· Ads for pornographic web sites
· Offers of software for collecting email
addresses and sending UCE
· Offers of bulk emailing services for
sending UCE
· Chain letters (for more information, see the
Knowledge Base document What is electronic
chain mail?)
· Illegally pirated software ("Warez")

78. Searching on the Net
Browsing on net is most popular application
Search engines such as msn, Google ,Yahoo are
frequently used
Many search engines used provide advance
features & use special syntax for helping the user
Not surprising that advertising companies in the
business of website development always prefer to
ensure there site appears in top 10 websites

79. I.T. for Management
End of Chapter 5