INTRODUCTION TO INTERNET

COMP 212 COMPUTER FUNDAMENTALS AND PROGRAMMING

HISTORY OF INTERNET

Long before the technology existed to actually build the Internet,

many scientists had already anticipated the existence of worldwide
networks of information.

Nikola Tesla toyed with the idea of a “world wireless system” in

the early 1900s, and visionary thinkers like Paul Otlet and
Vannevar Bush conceived of mechanized, searchable storage
systems of books and media in the 1930s and 1940s.
HISTORY OF INTERNET

Still, the first practical schematics for the Internet would not arrive
until the early 1960s, when MIT’s J.C.R. Licklider popularized the
idea of an “Intergalactic Network” of computers.

Shortly thereafter, computer scientists developed the concept of

“packet switching,” a method for effectively transmitting
electronic data that would later become one of the major building
blocks of the Internet.
HISTORY OF INTERNET

The first workable prototype of the Internet came in the late 1960s
with the creation of ARPANET, or the Advanced Research Projects
Agency Network.

Originally funded by the U.S. Department of Defense, ARPANET

used packet switching to allow multiple computers to
communicate on a single network.
HISTORY OF INTERNET

The technology continued to grow in the 1970s after scientists

Robert Kahn and Vinton Cerf developed Transmission Control
Protocol and Internet Protocol, or TCP/IP, a communications
model that set standards for how data could be transmitted
between multiple networks.

ARPANET adopted TCP/IP on January 1, 1983, and from there

researchers began to assemble the “network of networks” that
became the modern Internet.
HISTORY OF INTERNET

The online world then took on a more recognizable form in 1990,

when computer scientist Tim Berners-Lee invented the World
Wide Web.

While it’s often confused with the Internet itself, the web is
actually just the most common means of accessing data online in
the form of websites and hyperlinks.
THE INTERNET

A global system of interconnected computer networks that use the

standard internet protocol suite (TCP/ IP) to serve billions of users
worldwide.

It is a network of networks that consists of millions of private,

public, academic, business, and government networks, of local to
global scope, that are linked by a broad array of electronic,
wireless and optical networking technologies.
THE INTERNET

The Internet carries a vast range of information resources and

services, such as the interlinked hypertext documents of the World
Wide Web (WWW) and the infrastructure to support electronic
mail.
ADVANTAGES OF INTERNET

 E-MAIL
It is now an essential communication tools in business because
messages are delivered and received instantly anywhere in the
world, unlike traditional mail that takes a lot of time.

Email is free, fast and very cheap when compared to telephone, fax
and postal services.
ADVANTAGES OF INTERNET

 24 HOURS A DAY - 7 DAYS A WEEK

Internet is available, 24 x 7 days for usage.
ADVANTAGES OF INTERNET

 INFORMATION
It is probably the biggest advantage internet is offering because
there is a huge amount of information available on the internet for
just about every subject.

You can almost find any type of data on almost any kind of subject
that you are looking for by using search engines like google, yahoo,
msn, etc.
ADVANTAGES OF INTERNET

 ONLINE CHAT
You can access many ‘chat rooms’ on the web that can be used to
meet new people, make new friends, as well as to stay in touch
with old friends.
ADVANTAGES OF INTERNET

 SERVICES
Many services are provided on the internet like net banking, job
searching, purchasing tickets, hotel reservations, guidance services
on array of topics engulfing every aspect of life.
ADVANTAGES OF INTERNET

 COMMUNITIES
Communities of all types have sprung up on the internet.

Its a great way to meet up with people of similar interest and

discuss common issues.
ADVANTAGES OF INTERNET

 E-COMMERCE
There are many online stores and sites that can be used to look for
products as well as buy them using your credit card.

You do not need to leave your house and can do all your shopping
from the convenience of your home.
ADVANTAGES OF INTERNET

 ENTERTAINMENT
Internet provides facility to access wide range of Audio/Video
songs, plays films.

Many of which can be downloaded.

One such popular website is YouTube.

ADVANTAGES OF INTERNET

 SOFTWARE DOWNLOADS
You can freely download innumerable software like utilities,
games, music, videos, movies, etc. from the Internet.
LIMITATIONS OF INTERNET

 THEFT OF PERSONAL INFORMATION

Electronic messages sent over the Internet can be easily snooped
and tracked, revealing who is talking to whom and what they are
talking about.

If you use the Internet, your personal information such as your

name, address, credit card, bank details and other information can
be accessed by unauthorized persons.
LIMITATIONS OF INTERNET

 NEGATIVE EFFECTS ON FAMILY COMMUNICATION

It is generally observed that due to more time spent on Internet,
there is a decrease in communication and feeling of togetherness
among the family members.
LIMITATIONS OF INTERNET

 INTERNET ADDICTION
There is some controversy over whether it is possible to actually be
addicted to the Internet or not.

Some researchers, claim that it is simply people trying to escape

their problems in an online world.
LIMITATIONS OF INTERNET

 CHILDREN USING THE INTERNET

Most parents do not realize the dangers involved when their
children log onto the Internet.

When children talk to others online, they do not realize they could
actually be talking to a harmful person.
LIMITATIONS OF INTERNET

 CHILDREN USING THE INTERNET

Moreover, pornography is also a very serious issue concerning the
Internet, especially when it comes to young children.
LIMITATIONS OF INTERNET

 VIRUS THREAT
Computers are mainly getting these viruses from the Internet.

Virus is a program which disrupts the normal functioning of your

computer systems.

Computers attached to internet are more prone to virus attacks

and they can end up into crashing your whole hard disk.
LIMITATIONS OF INTERNET

 SPAMMING
It is often viewed as the act of sending unsolicited email.

This multiple or vast emailing is often compared to mass junk

mailings.

It needlessly obstruct the entire system.

TYPES OF INTERNET CONNECTION

 Dial Up Connection
 Leased Connection
 DSL Connection
 Cable Modem Connection
 VSAT
DIAL UP CONNECTION

It refers to an Internet connection that is established using a

modem.

The modem connects the computer to standard phone lines, which

serve as the data transfer medium.

When a user initiates a dial-up connection, the modem dials a

phone number of an Internet Service Provider (ISP) that is
designated to receive dial-up calls.
DIAL UP CONNECTION

After the dial-up connection has been established, it is active until

the user disconnects from the ISP.

Typically, this is done by selecting the “Disconnect” option using

the ISP’s software or a modem utility program.
DIAL UP CONNECTION

ADVANTAGES DISADVANTAGES
Low Price Slow speed
Secure connection – your IP Phone line is required
address continually changes
Offered in rural areas – you need Busy signals for friends and
a phone line family members
LEASED CONNECTION

Leased connection is a permanent telephone connection between

two points set up by a telecommunications common carrier.

Unlike normal dial-up connections, a leased line is always active.

The fee for the connection is a fixed monthly rate that is primarily
affected by the distance between end points and the speed of the
circuit.
LEASED CONNECTION

You can divide your connection into different lines for data and
voice communication or use the channel for one high speed data
circuit.

Dividing the connection is called multiplexing.

LEASED CONNECTION

ADVANTAGES DISADVANTAGES
SECURE AND PRIVATE: Leased lines can be expensive to
dedicated exclusively to the install and rent
customer
SPEED: symmetrical and direct Not suitable for single or home
workers
RELIABLE: minimum down time Lead times can be as long as 65
working days
LEASED CONNECTION

ADVANTAGES DISADVANTAGES
WIDE CHOICE OF SPEEDS: Distance dependent to nearest
bandwidth on demand, easily POP
upgradeable
Leased lines are suitable for in- Leased lines have traditionally
house office web hosting been the more expensive access
option.
DSL CONNECTION

Digital Subscriber Line (DSL) is a family of technologies that

provides digital data transmission over the wires of a local
telephone network.

DSL service is delivered simultaneously with wired telephone

service on the same telephone line.
DSL CONNECTION

This is possible because DSL uses higher frequency bands for data
separated by filtering.

On the customer premises, a DSL filter on each outlet removes the

high frequency interference, to enable simultaneous use of the
telephone and data.
DSL CONNECTION

The data bit rate of consumer DSL services typically ranges from
256 kbit/s to 40 Mbit/s in the direction to the customer
(downstream), depending on DSL technology, line conditions, and
service-level implementation.

In Asymmetric Digital Subscriber Line (ADSL), the data throughput

in the upstream direction, (the direction to the service provider) is
lower, hence the designation of asymmetric service.
DSL CONNECTION

In Symmetric Digital Subscriber Line (SDSL) services, the

downstream and upstream data rates are equal.
ADVANTAGES OF DSL CONNECTION

 SECURITY: Unlike cable modems, each subscriber can be

configured so that it will not be on the same network.

In some cable modem networks, other computers on the cable

modem network are left visibly vulnerable and are easily
susceptible to break in as well as data destruction.
ADVANTAGES OF DSL CONNECTION

 INTEGRATION: DSL will easily interface with ATM and WAN

technology.

 High bandwidth.

 Cheap line charges from the phone company.

 Good for “bursty” traffic patterns.

DISADVANTAGES OF DSL CONNECTION

 NO CURRENT STANDARDIZATION: A person moving from one

area to another might find that their DSL modem is just another
paperweight.

 Expensive.
DISADVANTAGES OF DSL CONNECTION

 Distance Dependence: The farther you live from the DSLAM

(DSL Access Multiplexer), the lower the data rate.
CABLE MODEM CONNECTION

A type of Network Bridge and modem that provides bi-directional

data communication via radio frequency channels on a HFC and
RFoG infrastructure.

Cable modems are primarily used to deliver Broadband Internet

access in the form of cable Internet, taking advantage of the high
bandwidth of a HFC and RFoG network.
ADVANTAGES OF CABLE MODEM
CONNECTION

 ALWAYS CONNECTED: A cable modem connection is always

connected to the Internet.

This is advantageous because you do not have to wait for your

computer to “log on” to the Internet; however, this also has the
disadvantage of making your computer more vulnerable to
hackers.
ADVANTAGES OF CABLE MODEM
CONNECTION

 BANDWIDTH: Cable modems have the potential to receive data

from their cable provider at speeds greater than 30 megabits per
second; unfortunately, this speed is rarely ever realized.

Cable lines are shared by all of the cable modem users in a given
area; thus, the connection speed varies depending upon the
number of other people using the Internet and the amount of data
they are receiving or transmitting.
ADVANTAGES OF CABLE MODEM
CONNECTION

 FILE TRANSFER CAPABILITIES: Downloads may be faster, but

uploads are typically slower.

Since the same lines are used to transmit data to and from the
modem, priority is often given to data traveling in one direction.
ADVANTAGES OF CABLE MODEM
CONNECTION

 SIGNAL INTEGRITY: Cable Internet can be transmitted long

distances with little signal degradation.

This means the quality of the Internet signal is not significantly

decreased by the distance of the modem from the cable provider.
ADVANTAGES OF CABLE MODEM
CONNECTION

 ROUTING: Cable routers allow multiple computers to be hooked

up to one cable modem, allowing several devices to be directly
connected through a single modem.

Wireless routers can also be attached to your cable modem.

ADVANTAGES OF CABLE MODEM
CONNECTION

 RELY ON EXISTING CONNECTIONS: Cable modems connect

directly to preinstalled cable lines.

This is advantageous because you do not need to have other

services, such as telephone or Internet, in order to receive Internet
through your cable modem.

The disadvantage is that you cannot have cable internet in areas

where there are no cable lines.
DISADVANTAGES OF CABLE MODEM
CONNECTION

 Once it is delivered to a region, however, such as a

neighborhood, it is split among that regions subscribers.

While increased capacity has diminished the effect somewhat, it is

still possible that users will see significantly lower speeds at peak
times when more people are using the shared connection.
DISADVANTAGES OF CABLE MODEM
CONNECTION

 Bandwidth equals money, so cable’s advantage in throughput

comes with a price.

 Cable internet is less accessible in remote areas.

VSAT

Short for Very Small Aperture Terminal, an earthbound station

used in satellite communications of data, voice and video signals,
excluding broadcast television.

A VSAT consists of two parts, a transceiver that is placed outdoors

in direct line of sight to the satellite and a device that is placed
indoors to interface the transceiver with the end user’s
communications device, such as a PC.
VSAT

The transceiver receives or sends a signal to a satellite transponder

in the sky.

The satellite sends and receives signals from a ground station

computer that acts as a hub for the system.

Each end user is interconnected with the hub station via the
satellite, forming a star topology.
VSAT

The hub controls the entire operation of the network.

For one end user to communicate with another, each transmission

has to first go to the hub station that then retransmits it via the
satellite to the other end user’s VSAT.
ADVANTAGES OF VSAT

 Costs Insensitive to Distance.

 Single Platform service delivery.
 Flexibility.
 Upgradeable.
 Low incremental costs per unit.
DISADVANTAGES OF VSAT

High start-up costs (hubs and basic elements must be in place

before the services can be provided).

 Higher than normal risk profiles.

 Severe regulatory restrictions imposed by countries that prevent

VSAT networks and solutions from reaching critical mass and
therefore profitability.
DISADVANTAGES OF VSAT

 Some service quality limitations such the high signal delays

(latency).

 Natural availability limits that cannot be eased.