A brief description about internet communication

1. INTERCONNECTED
NETWORK
PRESENTED BY:
ASST. PROF. GAGANA P

2. INTERNET:
The Giant Wide Area
Network
Accessing the Internet
Internet Organization
Cyber Ethics

3. 1.1 INTERNET: THE GIANT WIDE AREA
NETWORK
• The first sets of computers developed during the Second
World War were innately expensive and isolated. Eventually,
with their gradual decrease in price, researchers began to
implement experiments to connect these computers.

4. 1.1 INTERNET: THE GIANT WIDE AREA
NETWORK
• As a meta-network, or network of networks, the Internet
(acronym for INTERconnected NETwork)emerged to be a
promising technology for providing ubiquitous access.
• In 1969, ARPANET started as a federally funded research
project, which was initiated by the Advanced Research Project
Agency (ARPA) and the US Department of Defense (DoD).

5. 1.1 INTERNET: THE GIANT WIDE AREA
NETWORK
• The network was designed to operate without centralized
control.
• If a portion of the network failed, the remaining working
portions would still route packets from senders to
receivers over alternative paths.
• ARPANET used the Transmission Control Protocol
(TCP) for communication. TCP ensured that messages
were properly routed from sender to receiver.

6. WIRED NETWORK
LAN
MAN
WAN

7. LOCAL AREA NETWORK (LAN)
• A Local Area Network (LAN) is a network that is used for
communicating among computer devices, usually within
an office building or home.
• Though it is limited in size, typically spanning a few hundred
meters and no more than a mile, it is fast, with speeds from 10
Mbps to 10 Gbps with minimal infrastructure requirements,
low cost, and high security.
• LANs can be either wired or wireless.

8. METROPOLITAN AREA NETWORK (MAN)
• A Metropolitan Area Network (MAN) is optimized for a larger
geographical area than a LAN, ranging from several blocks
of buildings to entire cities typically covering an area ranging
from 5 to 50 km diametrically.

9. WIDE AREA NETWORK (WAN)
• A Wide Area Network (WAN) covers a large geographic area
such as country, continent or even whole world. It is two
or multiple LANs connected using devices such as bridges,
routers, or gateways, which enable them to share
resources.

10. WIRELESS NETWORK
•Wi-Fi is a wireless networking technology that allows devices
such as computers (laptops and desktops), mobile devices
(smart phones and wearables), and other equipment (printers
and video cameras) to interface with the Internet. It allows
these devices--and many more--to exchange information with
one another, creating a network.

11. WIRELESS NETWORK
•BLUETOOTH is a wireless networking technology that
allows device to communicate with each other over short
distance.
• It Is commonly used in smartphone, laptops and other portable
devices

12. WIRELESS NETWORK
• CELLULAR NETWORK use wireless technology to provide
mobile communication services

13. WHAT IS THE PURPOSE OF A WAN
CONNECTION?
• Wide-area networks (WANs) are the backbone of enterprise today.
With the digitization of resources, companies use WANs to do the
following:
• Communicate using voice and video.
• Share resources between employees and customers.
• Access data storage and remotely back up data.
• Connect to applications running in the cloud.
• Run and host internal applications.

14. • Another classification of networks focuses on the roles of the
networked computers.
• The millions of connected computing devices (also called hosts
or end-systems) that constitute the Internet, can be divided
into two basic types relying on their role classifications for
networks: the Peer-to-Peer networks (also known as a
workgroup) and Server-based networks (also known as a
Client/Server network).
• The difference between the two revolves around which
computer is in charge of the network.

15. CLIENT/SERVER NETWORK
• In the client/server model, all end
systems are divided into clients and
servers, each designed for specific
purposes.
• Clients have an active role and initiate a
communication session by sending
requests to servers.

16. PEER-TO-PEER NETWORK (P2P)
• In the P2P network architecture, all end systems have
equivalent capabilities and responsibilities and either party can
initiate a communication session.
• There is no central location for authenticating users, storing
files, or accessing resources.
• The P2P model does not have the notion of clients or servers
but only equal peers (a.k.a. servents, servent = SERVer
+ cliENT) that simultaneously function as both clients and

17. PEER-TO-PEER NETWORK (P2P)
• Pure P2P network: A P2P system that has no central service of
any kind.
• Hybrid P2P network: Pure P2P systems work well only in a
small-scale
• environment

18. Local Area
Networks
Distance
(meters)
10-3
100
103
106
Number of devices interconnected
1 10 100 1,000 10,000 >100,000
System/Stora
ge Area
Networks
Wide Area
Networks
Metropolitan
Area Networks
INTERCONNECTION NETWORK
DOMAINS

19. INTERCONNECTION NETWORK
DOMAINS
Local Area
Networks
10-3
100
103
106
Number of devices interconnected
1 10 100 1,000 10,000 >100,000
System/Stora
ge Area
Networks
Wide Area
Networks
Metropolitan
Area Networks
On-Chip
Interconnection
Networks/Networks-
on-Chip

20. Getting
Confused

21. MULTI-ACCESS NETWORK
• Multi-Access Network is also known as multi-point or
broadcast network , allow multiple devices to connect to
communicate over same network.
• This type of network can have different topologies like ring, star,
bus

22. Communicating over the Internet

23. TWO POPULAR MODELS
OPEN SYSTEMS
INTERCONNECTI
ON
TCP/IP MODEL

24. AS PER THE REPORTS HOW MANY NUMBER
OF STUDENTS USE THE INTERNET?
Statistical bar chart for available Internet users.

25. OSI REFERENCE MODEL

26. OSI VERSUS TCP/IP MODEL.

27. PROTOCOL LAYERING
• To communicate using the Internet system, a host must
implement the layered set of protocols comprising the Internet
protocol suite

29. INTERNET ADDRESSING
An IP address is a unique global address for a network interface. It is
32-bit logical address, composed of four 8-bit fields, called octets.
The address is represented in “dotted decimal notation” by grouping
the four octets. Each octet represents a decimal number in the range
0–255 (since 255 is the maximum 8-bit binary number), i.e., the
format of IP address is xxx.xxx.xxx.xxx, where each xxx is a number
from 0 to 255. These are unique numbers and controlled by address
registry. For example, 17.112.152.32 is the IP address for
www.apple.com, for www.amazon.com it is 54.239.26.128 and that for
www.dtu.ac.in is 122.160.182.54.

30. IP address is divided into two parts: a prefix which identifies the
physical network to which the host is attached and a suffix which
identifies a specific computer (host/node) on the network. Each
network on the Internet is assigned a unique network number
and each computer on a given network is assigned a unique
suffix

32. • Protocol: It specifies the transfer protocol that will be
used for retrieval of desired resource. Examples include
Hypertext Transfer Protocol (http), HTTP Secure
Protocol (https), and File Transfer Protocol (ftp).
Domain name: The Domain name is also known as
website name or host name. It is often divided into
three parts: www (optional), second level name (e.g.,
dtu.ac in www.dtu.ac.in), and top level name
(Organizational: 3-character code indicates the function
of the organization

33. Path: It is the directory or the folder on the server. It is
the path used to specify and perhaps find the resource
requested, i.e., a path to a file located on the web
server.
File name: The file name element of a URL is the file
name within that directory with an extension such as
htm, html, php, and so on.

34. DNS HIERARCHY
• The DNS is implemented as a distributed system and has a
hierarchical structure, that is, the name hierarchy can be
represented as a tree. Each node in the DNS tree represents a
DNS name. Each branch below a node is a DNS domain. DNS
domain can contain hosts or other domains (sub-domains). The
top-level domains are at the root of the tree followed by the
top-down sub-domains.

36. URL: Contains information about how to fetch a
resource from its location.
URLs always start with a protocol (http) and usually
contain information such as the network host name
(dtu.ac.in) and often a document path
(/Academics/syllabus.php).
For example:
http://dtu.ac.in/Web/Academics/syllabus.php
ftp://example.com/download.zip URN: Identifies a
resource by a unique and persistent name. It usually
starts
URI: The URI encompasses URLs, URNs, and other ways

37. ACCESSING THE INTERNET
• The Internet consists of millions of connected computing
devices, known as hosts or end systems, which are connected
together by communication links.
• The hosts are not usually directly attached to each other via a
single communication link. Instead, they are indirectly
connected to each other through intermediate switching
devices called routers.

38. Dial-up access: Dial-Up Connection works over an ordinary
phone line, using analog modems establishing the Point-to-
Point Protocol (PPP). As the personal computers are mostly
equipped with analog modems, there is usually no additional
money needed for hardware
High-speed access: A high-speed connection also known as the
broadband connection comprises of divergent options such as
Digital Subscriber Line (DSL), Integrated Services Digital Network
(ISDN) Lines, leased line, and cable Internet connections. DSL is a
family of all-digital, high-speed lines that use normal phone
wires with special modems.

39. • Wireless access: Another way to connect to the Internet is via a
Wireless access using Wi-Fi technology. A Wi-Fi enabled device,
such as a PC, game console, cell phone, MP3 player, or
personal data assistant (PDA), can connect to the Internet when
its within range of a wireless network connected to the Internet.

40. WEB BROWSER
• A web browser is a software program that retrieves, presents,
and traverses information resources on the Web. The primary
function of a browser is to identify the URL and bring the
information resource to user. To identify a web pages’ exact
location, a web browser relies on a URL. A URL, as described
previously, is a four-part addressing scheme that tells the web
browser:

41. • The transfer protocol to use for transporting the file
• The domain name of the computer on which the file resides
• The pathname of the folder or directory on the computer on
which the file resides
• The name of the file

42. CYBER ETHICS
• Cyber Ethics refers to the code of responsible behavior on the
Internet. It entails basic Internet etiquettes, also known as
Netiquettes, which are the set of rules or guidelines for
cyberspace behavior. The expected conduct must be ethical,
and users must act within the laws of society and cyberspace.

43. • Communicating, sharing, and contributing to e-society in a positive
manner
• To be respectful and courteous in communication (do not use rude or
offensive language)
• Avoid harming others (do not spread pictures, viruses, gossip,
information
about others, do not use others’ usernames and passwords, i.e., do
not
impersonate others and do not trespass in other’s files)
• Sharing network resources, being honest and trustworthy

44. THANK YOU……