Networks can be classified in two main ways - by geography and by component roles. By geography, networks include personal area networks (PANs), local area networks (LANs), metropolitan area networks (MANs), and wide area networks (WANs). By component roles, they include peer-to-peer networks, server-based networks, and client-server networks. The document provides details on each type of network classification.

1. Chapter 1
Basic Network Concepts

2. Overview
• Introduction to networks.
• Need for networks.
• Application of Computer Network
• Classification of networks.
– By Their Geography
– By Their Component Role

3. Introduction to Networks
• A network consists of two or
more entities or objects
sharing resources and information.
• Human Network:-
– Network of Human being eg:- social structure
– Nodes:- individuals , Links:-cellphone ,Email ,emotioal,
cultural etc
– Types:
A. Family Network: within family ,Mother-father-children
B. Peer Network: community & family eg:- school –family-work
C. Restaurant network : waiter –customer
D. Contact Network:- Job search

4. Computer Network
• A computer network consists of two
or more computing devices
connected to each other to share
resources and information.
•Communication & sharing of resources with other computers
takes place on the same network or entirely distinct networks.
•Computers on a network can act as a client or a server.
•A client is a computer that requests for resources.
•A server is a computer that controls and provides access to
resources.
•Network access to data must be evaluated carefully to avoid
security issues.

5. Need for Networks
• Enhance communication.
• Share resources.
• Facilitate centralized management.

6. Enhance Communication
• Computer networks facilitates interpersonal
communication via email, instant messaging,
chat room, telephone, video telephone &
video conferencing
• By using networks, information can be sent to
a larger audience in an extremely fast and
efficient manner.

7. Share Resources
• A copy of data or application stored at a single central
location is shared over a network. , thereby saving
storage space on individual computers
• Computer peripheral devices can be attached to a
computer and be shared in a network. Peripheral devices
include faxes, modems, scanners, plotters
• Equipments having common requirements can be shared
in order to reduce maintenance cost.
• Computer applications, which take up a considerable
amount of storage space, can be installed centrally on
the network, saving storage space

8. Facilitate Centralized Management
 Management of software : Software can be installed at a central
location using servers, where the installation files are made accessible
over the network .This reduces cost of buying expensive s/w
• Management of Network : Network administrator keeps track of
network speed, traffic , performance by using different tools.(eg:-
Network analyzer , Network management protocol)
• Keeping data backup :- data from computer system is copied from disk
to some other medium for keeping it safe. Backup policies:- full backup,
Replication , Incremental
• Centralized Network security:

9. Features of Network
• File Sharing
• Printer Sharing
• Application Services
• E-mail
• Remote Access
• Internet /Intranet
• Network Security

10. File Sharing
• Network file sharing is the process of copying files from one computer to
another using a live network connection.
• File Sharing With Microsoft Windows :Windows file folders can be shared
across a LAN. You can also set up security access restrictions that control
who can obtain the shared files.
• FTP File Transfers :FTP server holds all the files to be shared, while remote
computers running FTP client software can log in to the server to obtain
copies.
• P2P - Peer to Peer File Sharing:is a popular method for swapping large files
on the Internet, particularly music and videos. Unlike FTP, most P2P file
sharing systems do not use any central servers but instead allow all
computers on the network to function both as a client and a server.
eg:torrent

11. Printer Sharing
• By use of Operating System:All modern versions of
OS include a feature called File and Printer Sharing
that allows a printer connected to one PC to be
shared with other PCs on a local network.
• Printers Having Built-In Network Capability: network
printers, are specifically designed for connecting
directly to a computer network. It allow entering
configuration data through a small keypad and screen
on the front of the unit. The screen also displays error
messages
• print server : It is a networked computer with one or
more shared printers

12. Application Services
• Sharing application on network eg: MS-office.
When a client (don’t have MS-office)wants to
run the program then application loads from
server into clients own memory
• Shared installation:-share all setup file on
server

13. E-mail
• electronic mail, the transmission of messages
over networks.
• Today's email systems are based on a store-and-forward
model. Email servers accept, forward, deliver, and store
messages.
• Types:
– Webmail :This allows users to log into the email
account by using a web browser to send and receive
their email eg:gmail
– POP3 email services:email messages are downloaded
to the client device (i.e. a computer) and then they
are deleted from the mail server.

14. Remote access
• allows logging into a system as an authorized
user without being physically present at its
keyboard
• Remote Desktop :eg:remote desktopsupport
• Remote Access to Files : remote network access
allows files to be read from and written to the
target, even without remote desktop capability
in place.

15. Classification of Networks
• Classification by network geography.
• Classification by component roles.

16. Classification by Network
Geography
• Networks are frequently classified according
to the geographical boundaries spanned by
the network itself.
• eg: PAN,LAN, MAN ,WAN,CAN and MAN are
the basic types of classification, of which LAN
and WAN are frequently used.

17. Local area network (LAN):
– A LAN covers a relatively small area such as a classroom, school,
or a single building.
– LANs are inexpensive to install and also provide higher speeds.
– LANs are also typically owned, controlled, and managed by a
single person or organization.
– They also tend to use certain connectivity technologies,
primarily Ethernet and Token Ring.
– On a single LAN, computers and servers may be connected by
cables or wirelessly
– High rate of data transmission :Is very fast, with speeds from 10
Mbps to 10 Gbps
• LAN’s enable the sharing of resources such as files or hardware
devices that may be needed by multiple users

18. Local area network
Classification by Network
Geography

19. LAN basics
• LAN’s can either be wired or wireless. Eg: twisted pair in wired
• Nodes in a LAN are linked together with a certain topology. Eg:BUS
• A node is defined to be any device connected to the network. This
could be a computer, a printer etc.
• A Hub is a networking device that connects multiple segments of
the network together
• A Network Interface Card (NIC) is the circuit board that is used to
connect computers to the network. In most cases, this is an
Ethernet card plugged in a computer’s motherboard
• The Network Operating System (NOS) is the software that enables
users to share files and hardware and communicate with other
computers. Examples of NOS include: Windows XP, Windows NT,
Sun Solaris, Linux, etc..
• Resource sharing in a LAN is accomplished with different access
methods. These include: Token based access ,CSMA/CD

20. Metropolitan area network (MAN):
– A MAN spans the distance of a typical metropolitan
city.
– The cost of installation and operation is higher.
– MANs use high-speed connections such as fiber optics
to achieve higher speeds.
– Types:-
• single network such as cable tv
• Connecting multiple LANs into a larger network .
– It may wholly owned by a company or it may be
service provided by public company such as telephone
company(Switched Multi-megabit Data Service SMDS)

21. Metropolitan area network
MAN

22. Wide area network (WAN):
– WANs span a larger area than a single city.(country)
– These use long distance telecommunication networks for
connection, thereby increasing the cost.
– The Internet is a good example of a WAN.
– WAN utilized public, leased line, satellite channel ,private
communication equipment in combination
– WAN which is wholly Owned by Single company refereed
as Enterprise network
– Because of large distance in WAN , the propogation delay
& variable signal travel times are major problem
– Uses Mesh topology majorly

23. Wide area network
WAN

24. Personal Area Network(PAN)
• It is organized around individual person eg:
cellphone with earphone
• A network covering a very small area, usually a
small room(10m).
• The best known wireless PAN network technology
is Bluetooth,
• The most popular wired PAN is USB.
• PANs can be viewed as a special type (or subset)
of local area network (LAN) that supports one
person instead of a group.

26. Campus Area Network (CAN)
• CAN is a computer network made up of an
interconnection of local area networks (LANs) within a
limited geographical area
• The networking equipments (switches, routers) and
transmission media (optical fiber, copper plant, Cat5
cabling etc.) are almost entirely owned by
the campus tenant / owner: an enterprise, university,
government etc.
• all of the nodes in a campus network are interconnected
by means ofoptical fiber media, taking advantage
of Gigabit Ethernet or 10-Gigabit Ethernet technology. In
some cases, Wi-Fi hot spots or even a hot zone make up
the user end of the network,

27. CAN

28. Classification by Component Roles
• Networks can also be classified according to
the roles that the networked computers play
in the network’s operation.
• Peer-to-peer, server-based, and client-based
are the types of roles into which networks are
classified.

29. Classification by Component Roles
Peer-to-peer:
– In a peer-to-peer network, all computers are considered
equal.
– Each computer controls its own information and is capable
of functioning as either a client or a server depending
upon the requirement.
– Peer-to-peer networks are inexpensive and easy to install.
– They are popular as home networks and for use in small
companies.

30. Classification by Component Roles
Peer-to-peer (continued):
– Most operating systems come with built-in peer-
to-peer networking capability.
– The maximum number of peers that can operate
on a peer-to-peer network is ten.
– Each peer shares resources and allows others
open access to them.

31. Classification by Component Roles
Peer-to-peer (continued):
– Peer-to-peer networks become difficult to manage
when more security is added to resources, since
the users control their security by password-
protecting shares.
– Shares can be document folders, printers,
peripherals, and any other resource that they
control on their computers.

32. Classification by Component Roles
Peer-to-peer network

33. Classification by Component Roles
Server-based:
– A server-based network offers centralized control
and is designed for secure operations.
– In a server-based network, a dedicated server
controls the network.

34. Classification by Component Roles
Server-based (continued):
– A dedicated server is one that services the
network by storing data, applications, resources,
and also provides access to resources required by
the client.
– These servers can also control the network’s
security from one centralized location or share it
with other specially configured servers.

35. Classification by Component Roles
Server-based network

36. Classification by Component Roles
– Client Server based network servers process requests from
clients and return just the results.
– Very Reliable
– Better Performance: These networks take advantage of the
powerful processing capabilities of both the client and the
server.
– Application servers and communications servers are
examples of clientserver-based networks.
– Specialized network Operating System required
– If server fails entire system fails
– Centralized Backup Taking Backup is easier
– Require professional administrator
– More Network intensive & expensive

37. Classification by Component Roles
Client-based network

38. Summary
• A network consists of two or more entities sharing
resources and information.
• A computer network consists of two or more
computers that are connected and are able to
communicate.
• The basic purpose of networks is to enable
effective communication, share resources, and
facilitate centralized management of data.
• Networks can be classified according to their
geographical boundaries or their component roles.