3. Introduction
• What is a computer network?
• A computer network, or data network, is a digital telecommunications network which
allows nodes to share resources. In computer networks, computing devices exchange
data with each other using connections (data links) between nodes.
• Why is a network needed?
• Network is nothing but a medium to transfer message or simply say data, let us clear
this with a real life example, suppose you are travelling by your car fromWardha to
Nagpur, in that scenario the road is a network and your car is the packet travelling
through this network and you of course are the data enclosed in the packet.
• What are the different types of network?
• We will discuss it in the next section.
4. Types of network
• Broadly network can be classified into four types depending on the
scalability of the network viz,
• PAN
• LAN
• MAN
• WAN
• These types will be discussed in the next section
5. PAN
• PAN stand for Personal Area Network.
• A personal area network (PAN) refers to the interconnection of information
technology devices or gadgets within the environment of an individual user.
• Typically the range lies within 10 meters or 33 feet .
• These interconnected devices might include laptop computers, PDAs,
cellphones, printers, PCs or other wearable computer devices.
6. PAN
• Also known as a wireless personal network (WPAN).
• Typically uses Bluetooth for connecting devices.
• NFC is a newly emerged type of PAN technology.
• PANs can be wired, such as USB or FireWire, or they can be wireless, such as
infrared,ZigBee, Bluetooth and ultrawideband
8. What can personal are networks do?
• Wireless connections between PCs and peripherals can free up floor space,
remove unwanted cables and liberate floor plans.
• Connected Bluetooth devices can automatically synchronise data downloads
and uploads, and exchange information.
• Mobile employees can use Bluetooth-equipped devices to access office-
based peripherals such as printers, if these support Bluetooth technology.
9. Advantages and disadvantages
• PANs are efficient, cost-effective and convenient.
• Some PANs can interact badly with other wireless networking technologies
using the same radio bands.
• Bluetooth networks are relatively secure, but have slow data rates.
• Bluetooth is a short-range solution – up to ten meters - and is not suitable for
wireless connection over larger distances.
10. LAN
• LAN stands for Local Area Network
• It covers, as the name suggests, a local area.
• This usually includes a local office and they're also pretty common in homes
now, thanks to the spread of Wi-Fi.
• Whether wired or wireless, nearly all modern LANs are based on Ethernet.
11. LAN
• A local area network (LAN) is a group of computers and associated devices
that share a common communications line or wireless link to a server.
• Computers and other mobile devices use a LAN connection to share
resources such as a printer or network storage.
• A local area network may serve as few as two or three users (for example, in
a small-office network) or several hundred users in a larger office.
13. Advantages of LAN
• The basic LAN implementation does not cost too much.
• It is easy to control and manage the entire LAN as it is available in one small
region.
• The LAN configuration is very easy due to availability of required protocols in
the Operating System (OS) itself.
• It is easy to share common resources such as printers and internet line
among multiple LAN users.
14. Disadvantages of LAN
• LAN covers small geographical area.
• Security issues are big concern as it is easy to have access to programs and
data of peers. Special security measures are needed to stop unauthorized
access.
• It is difficult to setup and maintain LAN and requires skilled technicians and
network administrators.
• In the server based LAN architecture, if server develops some fault, all the
users are affected.
15. MAN
• MAN stands for Metropolitan Area Network.
• A metropolitan area network (MAN) is a computer network that
interconnects users with computer resources in a geographic area or region
larger than that covered by even a large local area network (LAN) but smaller
than the area covered by a wide area network (WAN).
• The term MAN is applied to the interconnection of networks in a city into a
single larger network which may then also offer efficient connection to a
wide area network
16. MAN
• It is also used to mean the interconnection of several local area networks in
a metropolitan area through the use of point-to-point connections between
them.
• It interconnects number of LANs using high capacity backbone technology.
• MANs are used to build networks with high data connection speeds for
cities and towns.
18. Advantages of MAN
• It utilizes drawbacks of both LAN and WAN to provide larger and controllable
computer network.
• MAN requires fewer resources compare to WAN. This saves the
implementation cost.
• It helps people interface fast LANs together. This is due to easy
implementation of links.
• It provides higher security compare to WAN.
19. Disadvantages of MAN
• It is difficult to manage the network once it becomes large.
• It is difficult to make the system secure from hackers and industrial
espionage.
• Network installation requires skilled technicians and network administrators.
This increases overall installation and management costs.
• It requires more cables for connection from one place to the other compare
to LAN.
20. WAN
• WAN stands for Wide Area Network
• A wide area network (WAN) is a telecommunications network or computer
network that extends over a large geographical distance/place.
• Wide area networks are often established with leased telecommunication
circuits.
21. WAN
• Business, education and government entities use wide area networks to relay
data to staff, students, clients, buyers, and suppliers from various locations
across the world
• The Internet may be considered a WAN.
• The WAN is a network which is a collection of LANs and other network types
connected using router. It covers large geographical distance compare to LAN
and MAN types.
23. Advantages of WAN
• WAN covers larger geographical area. Hence business offices situated at
longer distances can easily communicate.
• Like LAN, it allows sharing of resources and application softwares among
distributed workstations or users.
• The software files are shared among all the users. Hence all will have access
to latest files. This avoids use of previous versions by them.
• Organizations can form their global integrated network through WAN.
Moreover it supports global markets and global businesses.
24. Disadvantages of WAN
• Initial investment costs are higher.
• It is difficult to maintain the network. It requires skilled technicians and
network administrators.
• There are more errors and issues due to wide coverage and use of different
technologies. Often it requires more time to resolve issues due to
involvement of multiple wired and wireless technologies.
• It has lower security compare to LAN and MAN due to wider coverage and
use of more technologies.
