Chapter -2
Internet and its Application
The Internet is a network of computers that links many different types of computers all over the
world. It is the network of networks sharing a common mechanism for addressing (identifying)
computers, and a common set of communication protocols.
OR
A global collection of individual networks, connected to each other by different networking
devices and function as a single large network is called an internetwork of computers or
Internet. It is a window to global information super highway. It is a world wide network of
networks.
History of Internet
It was first proposed by J C R Linklider of MIT ( Massachusetts Institute of Technology) in 1962.
His intention was to share military information and scientific information between different
organization situated at different places in united States.
During that period Leonard Kleinrock of University of California developed the theory of packet
switching which is backbone of today’s internet data transmission.
In year 1968 National research Laboratory of England was installed the first ever network of
computers.
In 1969 ARPA ( Advanced Research Project Agency ) at Pentagon was established a more
advanced network connecting four high speed computers. This network is called as ARPAnet. By
1972, ARPAnet had 23 nodes.
In 1972 Raymond Samuel Tomlison of United States incorporated @ ( email symbol) to link the
user name and the address.
The First ever international node of ARPAnet was set up in 1973 in England and Norway.
In 1974 Bob Khan and Vint Cerf put the foundation of Network Transfer protocol and later it
was standardized as TCP/IP for ARPAnet in 1983.
In 1984 a new technique called as Domain Name System was introduced using IP( Internet
Protocol ) address .
1990 ARPAnet was ceased and WAIS( Wide area Information Server), and Gopher were released
for paying the way for modern Internet System.
In 1992 Tim Berners Lee released WWW by CERN ( European Organisation for Nuclear
Research). Now a days WWW is the gateway to any internet transmission. He first wrote the
WWW client and WWW server and define the Internet browser as Mosaic latter it was moved to
Netscape Communication and names as Netscape Navigator. This browser dominated internet
browsing until Microsoft Inc introduced its “ Internet Explorer”.
Internet Backbone and its features :
, A Backbone is a larger communication line that carries data gathered from smaller lines that
interconnected with it.
- At local level a backbone is set of LANs connect to WAN.
- On the Internet or WANs a backbone is a set of path that local and regional network connect
together for long distance interconnection and each connection points are network nodes or
DSEs. ( Data switching exchanges)
An Internet backbone refers to one of the principal data routes between large, strategically
interconnected networks and core routers on the Internet. It is a very high speed data transmission
line that provides networking facilities to Internet service Providers all around the world. Internet
backbones are the largest data connections lines on the Internet.
The first Internet backbone was named NSFNET ( National Service Foundation Network) founded by
U.S government in 1987. It was a T1 line with 170 smaller networks operated at 1.544 Mbps. It was
a combination of fiber-optic trunk line.
Each country has at least one backbone network that operates at very high speed and carries bulk of
traffic. Backbone networks are primarily owned by commercial, educational, government and
military entities because they provide a consistent way for ISPs to keep and maintain online
information in a secure manner.
Some large companies providing backbone connectivity – BSNL, Airtel, VSNL International, British
Telecom, France Telecom, Ortel communication, Tata Tele services.
These backbones are constructed of fiber optic cable called OC( Optical carrier). Oc connection use
SONET( Synchronous Optical Network) technology .
Features of an Internet backbone
a) ISPs are either connected directly to their contingency backbones or to some larger ISPs.
b) The smaller networks are interlinked to support the backup in case of failure of Internet. This is
done through transit agreement and peering process.
c) The transit agreement is a monetary contract between several larger and smaller ISPs.
Different Network technologies
Token Ring : Token Ring network is a local area network in which all computers are connected in a ring
or star topology. Here a bit or token-passing scheme is used in order to prevent the collision of data
between two computers that want to send messages at the same time. This token ring protocol is
second widely used protocol after Ethernet.
Ethernet : Ethernet is the most widely installed local area network technology with specified standard
IEEE 802.3. Ethernet was originally developed by XEROX , earlier specified as Alohanet and further
developed by XEROX, DEC and Intel. Ethernet LAN uses coaxial cable or special grades of twisted pair. It
is also used in wireless LAN. Ethernet system is known as 10BASE-T providing transmission speed up to
10Mbps.Ethernet system uses CSMA/CD protocol
, Fiber Distribution Data Interface : FDDI provides standard data transmission of LAN in range up to 200
km. FDDI protocol is a token ring network. FDDI uses IEEE 802.4 token bus ( timed token protocol).Users
of MAN also uses FDDI as it contains two token ring , one is primary and other one for back up incase
failure of primary ring. When a network has no requirement, both ring can carry data extending capacity
to 200 Mbps
Features of Internet :
a. Geographic Distribution: The geographic distribution of the Internet continues to
spread, around the world & even beyond. The geographically distributed groups of
people in Internet are news groups, mailing lists, IRC, E-Mail groups etc. Thus Internet is
a true multi-way electronic global village.
b. Robust Architecture: The Internet is the most robust communications network even
designed. It has no irreplaceable central control, administration or authority.
c. Near Light Speed: Digital Information such as Internet packets travel at 2/3 rd of the
speed of light on copper wire & on fiber optic cables.
d. Universal Access: the Internet is based on a common standard, the TCP/IP protocol
which provides the universal access.
e. Internet Growth Rates: The growth rate of the Internet exceeds that of any previous
technology. It is growing exponentially in three different directions i.e. size, processing
powers & software sophistication.
f. The Digital Advantage: The Internet is a digital medium based on data made up of
discrete 1’s and 0’s. So there is no drift that can introduce error.
Internet Access :Internet Access is the process that enables individuals and organizations
to connect to the Internet using computer terminals, computers, mobile devices, sometimes via
computer networks. Once the internet connection is established user can access various
services of the Internet.
Types of Internet connection :
Gateway Access :
Gateway access is known as Level-one connection. It is the access to the Internet from a
network, which is not on the network. The gateway allows the two different types of networks
to ‘talk ‘ to each other. It reformats information from one network so that it’s compatible with
the other network. It connects a LAN to other LAN and to WAN also. A gateway device allows
users to protect, share, store and access data over any available network.
a) Though Dial-up Connection :
Dial-up connection is known as level two connection. A dial up service connects to the internet
through a phone line. You connect to internet by using phone line to dial into an ISP’s line. This
connection allows only one computer at a time per line to be connected. When the line is
connected to the internet, voice communication would not be available over it. In this
connection modems are used to translate digital into analogue signals and communicating with
Internet and its Application
The Internet is a network of computers that links many different types of computers all over the
world. It is the network of networks sharing a common mechanism for addressing (identifying)
computers, and a common set of communication protocols.
OR
A global collection of individual networks, connected to each other by different networking
devices and function as a single large network is called an internetwork of computers or
Internet. It is a window to global information super highway. It is a world wide network of
networks.
History of Internet
It was first proposed by J C R Linklider of MIT ( Massachusetts Institute of Technology) in 1962.
His intention was to share military information and scientific information between different
organization situated at different places in united States.
During that period Leonard Kleinrock of University of California developed the theory of packet
switching which is backbone of today’s internet data transmission.
In year 1968 National research Laboratory of England was installed the first ever network of
computers.
In 1969 ARPA ( Advanced Research Project Agency ) at Pentagon was established a more
advanced network connecting four high speed computers. This network is called as ARPAnet. By
1972, ARPAnet had 23 nodes.
In 1972 Raymond Samuel Tomlison of United States incorporated @ ( email symbol) to link the
user name and the address.
The First ever international node of ARPAnet was set up in 1973 in England and Norway.
In 1974 Bob Khan and Vint Cerf put the foundation of Network Transfer protocol and later it
was standardized as TCP/IP for ARPAnet in 1983.
In 1984 a new technique called as Domain Name System was introduced using IP( Internet
Protocol ) address .
1990 ARPAnet was ceased and WAIS( Wide area Information Server), and Gopher were released
for paying the way for modern Internet System.
In 1992 Tim Berners Lee released WWW by CERN ( European Organisation for Nuclear
Research). Now a days WWW is the gateway to any internet transmission. He first wrote the
WWW client and WWW server and define the Internet browser as Mosaic latter it was moved to
Netscape Communication and names as Netscape Navigator. This browser dominated internet
browsing until Microsoft Inc introduced its “ Internet Explorer”.
Internet Backbone and its features :
, A Backbone is a larger communication line that carries data gathered from smaller lines that
interconnected with it.
- At local level a backbone is set of LANs connect to WAN.
- On the Internet or WANs a backbone is a set of path that local and regional network connect
together for long distance interconnection and each connection points are network nodes or
DSEs. ( Data switching exchanges)
An Internet backbone refers to one of the principal data routes between large, strategically
interconnected networks and core routers on the Internet. It is a very high speed data transmission
line that provides networking facilities to Internet service Providers all around the world. Internet
backbones are the largest data connections lines on the Internet.
The first Internet backbone was named NSFNET ( National Service Foundation Network) founded by
U.S government in 1987. It was a T1 line with 170 smaller networks operated at 1.544 Mbps. It was
a combination of fiber-optic trunk line.
Each country has at least one backbone network that operates at very high speed and carries bulk of
traffic. Backbone networks are primarily owned by commercial, educational, government and
military entities because they provide a consistent way for ISPs to keep and maintain online
information in a secure manner.
Some large companies providing backbone connectivity – BSNL, Airtel, VSNL International, British
Telecom, France Telecom, Ortel communication, Tata Tele services.
These backbones are constructed of fiber optic cable called OC( Optical carrier). Oc connection use
SONET( Synchronous Optical Network) technology .
Features of an Internet backbone
a) ISPs are either connected directly to their contingency backbones or to some larger ISPs.
b) The smaller networks are interlinked to support the backup in case of failure of Internet. This is
done through transit agreement and peering process.
c) The transit agreement is a monetary contract between several larger and smaller ISPs.
Different Network technologies
Token Ring : Token Ring network is a local area network in which all computers are connected in a ring
or star topology. Here a bit or token-passing scheme is used in order to prevent the collision of data
between two computers that want to send messages at the same time. This token ring protocol is
second widely used protocol after Ethernet.
Ethernet : Ethernet is the most widely installed local area network technology with specified standard
IEEE 802.3. Ethernet was originally developed by XEROX , earlier specified as Alohanet and further
developed by XEROX, DEC and Intel. Ethernet LAN uses coaxial cable or special grades of twisted pair. It
is also used in wireless LAN. Ethernet system is known as 10BASE-T providing transmission speed up to
10Mbps.Ethernet system uses CSMA/CD protocol
, Fiber Distribution Data Interface : FDDI provides standard data transmission of LAN in range up to 200
km. FDDI protocol is a token ring network. FDDI uses IEEE 802.4 token bus ( timed token protocol).Users
of MAN also uses FDDI as it contains two token ring , one is primary and other one for back up incase
failure of primary ring. When a network has no requirement, both ring can carry data extending capacity
to 200 Mbps
Features of Internet :
a. Geographic Distribution: The geographic distribution of the Internet continues to
spread, around the world & even beyond. The geographically distributed groups of
people in Internet are news groups, mailing lists, IRC, E-Mail groups etc. Thus Internet is
a true multi-way electronic global village.
b. Robust Architecture: The Internet is the most robust communications network even
designed. It has no irreplaceable central control, administration or authority.
c. Near Light Speed: Digital Information such as Internet packets travel at 2/3 rd of the
speed of light on copper wire & on fiber optic cables.
d. Universal Access: the Internet is based on a common standard, the TCP/IP protocol
which provides the universal access.
e. Internet Growth Rates: The growth rate of the Internet exceeds that of any previous
technology. It is growing exponentially in three different directions i.e. size, processing
powers & software sophistication.
f. The Digital Advantage: The Internet is a digital medium based on data made up of
discrete 1’s and 0’s. So there is no drift that can introduce error.
Internet Access :Internet Access is the process that enables individuals and organizations
to connect to the Internet using computer terminals, computers, mobile devices, sometimes via
computer networks. Once the internet connection is established user can access various
services of the Internet.
Types of Internet connection :
Gateway Access :
Gateway access is known as Level-one connection. It is the access to the Internet from a
network, which is not on the network. The gateway allows the two different types of networks
to ‘talk ‘ to each other. It reformats information from one network so that it’s compatible with
the other network. It connects a LAN to other LAN and to WAN also. A gateway device allows
users to protect, share, store and access data over any available network.
a) Though Dial-up Connection :
Dial-up connection is known as level two connection. A dial up service connects to the internet
through a phone line. You connect to internet by using phone line to dial into an ISP’s line. This
connection allows only one computer at a time per line to be connected. When the line is
connected to the internet, voice communication would not be available over it. In this
connection modems are used to translate digital into analogue signals and communicating with
