Network
o The collection of interconnected
computers is called a
computer network.
o Two computers are said to be
interconnected if they are
capable of sharing and exchanging
information.
Need
o Resource Sharing
o Reliability
o Cost Factor
o Communication Medium
Resource Sharing means to make all programs, data
and peripherals available to anyone on the network
irrespective of the physical
location of the resources and the user.
Reliability means to keep the copy of a file
on two or more different machines, so if one of them is unavailable (due to
some hardware crash or any other) them its other copy can be used.
Cost factor means it greatly reduces the cost
since the resources can be shared
Communication
Medium means one can send messages and
whatever the changes at one end are done can be immediately noticed at another.
Evolution of
Networking
1. ARPANET:In 1969, The US govt. formed an agency
named ARPANET (Advanced Research Projects
Agency NETwork) to connect
computers at various universities and defense agencies. The main objective
of ARPANET was to develop a
network that could continue to function efficiently even in the event of a
nuclear attack.
2. Internet
(INTERconnection NETwork): The Internet is a worldwide network of computer networks.
It is not owned by anybody.
3. Interspace:InterSpace is a client/server
software program that allows multiple users to communicate
online with real – time audio,
video and text chat in dynamic 3D environments.
SWITCHING
TECHNIQUES
Switching techniques are used for
transmitting data across networks.
Different types are:
1. Circuit
Switching: In the
Circuit Switching technique, first, the complete end-to-end transmission path
between the source and the destination computers is established and then the
message is transmitted through the path. The main advantage of this technique
is guaranteed delivery of the message. Mostly used for voice communication.
2. Message
Switching: In the
Message switching technique, no physical path is established between sender and
receiver in advance. This technique follows the store and forward mechanism.
3. Packet
Switching: In this switching technique fixed size of packet can be transmitted across
the network
|
Comparison between the Various
Switching Techniques: Criteria
|
Circuit
Switching
|
Message
Switching
|
Packet
Switching
|
|
Path established in advance
|
Yes
|
No
|
No
|
|
Store and forward technique
|
No
|
Yes
|
Yes
|
|
Message follows multiple routes
|
No
|
Yes
|
Yes
|
DATA COMMUNICATION TERMINOLOGIES
Data channel: - The information / data carry
from one end to another in the network by channel.
Baud & bits per second (bps)
:- It’s used to measurement for the information carry of a communication
channel. Measurement
Units: - bit
1 Byte= 8 bits
1 KBPS ( Kilo Byte Per Second)=
1024 Bytes
1 Kbps (kilobits Per Second) =
1024 bits
1 Mbps ( Mega bits Per Second
)=1024 Kbps
Bandwidth: - It is amount of
information transmitted or receives per unit time.
Transmission media:
1. Twisted pair
cable: - It consists of two identical 1
mm thick copper wires
insulated and twisted together.
The twisted pair cables are twisted in order to
reduce crosstalk and
electromagnetic induction.
Advantages:
(i) It is easy to install and
maintain.
(ii) It is very inexpensive
Disadvantages:
(i) It is incapable to carry a
signal over long distances without the use of repeaters.
(ii) Due to low bandwidth, these
are unsuitable for broadband applications.
2. Co-axial Cables: It consists of a solid wire core
surrounded by
one or more foil or braided wire
shields, each separated from the
other by some kind of plastic
insulator. It is mostly used in the
cable wires.
Advantages:
(i) Data transmission rate is
better than twisted pair cables.
(ii) It provides a cheap means of
transporting multi-channel
television signals around
metropolitan areas.
Disadvantages:
(i) Expensive than twisted pair
cables.
(ii) Difficult to manage and
reconfigure.
3. Optical fiber: - An optical fiber consists of thin
glass fibers that can
carry information in the form of
visible light.
Advantages:
(i) Transmit data over long
distance with high security.
(ii) Data transmission speed
is high
(iii) Provide better noise
immunity
(iv) Bandwidth is up to 10 Gbps.
Disadvantages:
(i) Expensive as compared to
other guided media.
(ii) Need special care while
installation?
4. Infrared: - The infrared light transmits
data through the air and can
propagate throughout a room, but
will not penetrate walls. It is a secure medium of signal transmission.
The infrared transmission has
become common in TV remotes, automotive garage doors, wireless
speakers etc.
5. Radio Wave: - Radio Wave an electromagnetic
wave
with a wavelength between 0.5 cm
and 30,000m. The
transmission making use of radio
frequencies is termed as
radio-wave transmission
Advantages:
(i) Radio wave transmission
offers mobility.
(ii) It is cheaper than laying
cables and fibers.
(iii) It offers ease of
communication over difficult terrain.
Disadvantages:
(i) Radio wave communication is
insecure communication.
(ii) Radio wave propagation is
susceptible to weather effects like rains, thunder storms etc.
6. Microwave Wave: - The Microwave transmission is a
line of sight transmission. Microwave signals travel at a higher frequency than
radio waves and are popularly used for transmitting data over long distances.
Advantages:
(i) It is cheaper than laying
cable or fiber.
(ii) It has the ability to
communicate over oceans.
Disadvantages:
(i) Microwave communication is an
insecure communication.
(ii) Signals from antenna may
split up and transmitted in different way to different antenna which leads to
reduce to signal strength.
(iii) Microwave propagation is
susceptible to weather effects like rains, thunder storms etc.
(iv) Bandwidth allocation is
extremely limited in case of microwaves.
7. Satellite link: - The satellite transmission is
also a kind of line of sight transmission that is used to transmit signals
throughout the world.
Advantages:
(i) Area covered is quite large.
(ii) No line of sight
restrictions such as natural mountains, tall building, towers etc.
(iii) Earth station which
receives the signals can be fixed position or relatively mobile.
Disadvantages:-
(i) Very expensive as compared to
other transmission mediums.
(ii) Installation is extremely
complex.
(iii) Signals sent to the
stations can be tampered by external interference
Network devices:
Modem: A MODEM (MOdulator DEModulator)
is an electronic device that enables a computer to transmit data over telephone
lines. There are two types of modems, namely, internal modem and external
modem.
RJ45 connector: - The RJ-45(Registered Jack)
connectors are the plug-in devices used in the networking and
telecommunications applications. They are used primarily for connecting LANs,
particularly Ethernet.
Ethernet Card: - It is a hardware device that
helps in connection of nodes within a network.
Hub: A hub is a hardware device used
to connect several computers together. Hubs can be either active or passive.
Hubs usually can support 8, 12 or 24 RJ45 ports.
Switch: A switch (switching hub) is a
network device which is used to interconnect computers or devices on a network.
It filters and forwards data packets across a network. The main difference
between hub and switch is that hub replicates what it receives on one port onto
all the other ports while switch keeps a record of the MAC addresses of the
devices attached to it.
Gateway: A gateway is a device that
connects dissimilar networks.
Repeater: A repeater is a network device
that amplifies and restores signals for long distance transmission.
Network topologies
and types
Topology :
· Topology refers to the way in
which the workstations attached to the network are interconnected.
The BUS Topology: - The bus topology uses a common
single cable to connect all the workstations. Each computer performs its task
of sending messages without the help of the central server. However, only one
workstation can transmit a message at a particular time in the bus topology.
Advantages:
(i) Easy to connect and install.
(ii) Involves a low cost of
installation time.
(iii) Can be easily extended.
Disadvantages:-
(i) The entire network shuts down
if there is a failure in the central cable.
(ii) Only a single message can
travel at a particular time.
(iii) Difficult to troubleshoot
an error.
The STAR Topology: - A STAR topology is based on a
central node which acts as a hub. A STAR topology is common in homes networks
where all the computers connect to the single central computer using it as a
hub.
Advantages:
(i) Easy to troubleshoot
(ii) A single node failure does
not affect the entire network.
(iii) Fault detection and removal
of faulty parts is easier.
(iv) In case a workstation fails,
the network is not affected.
Disadvantages:-
(i) Difficult to expand.
(ii) Longer cable is required.
(iii) The cost of the hub and the
longer cables makes it expensive over others.
(iv) In case hub fails, the
entire network fails.
The TREE Topology:
- The tree topology combines the
characteristics of the linear bus and the star topologies. It consists of
groups of star – configured workstations connected to a bus backbone cable.
Advantages:
(i) Eliminates network
congestion.
(ii) The network can be easily
extended.
(iii) Faulty nodes can easily be
isolated from the rest of the network.
Disadvantages:
(i) Uses large cable length.
(ii) Requires a large amount of
hardware components and hence is expensive.
(iii) Installation and
reconfiguration is very difficult.
Types of Networks:
LAN (Local Area
Network): A Local Area Network (LAN) is a
network that is confined to a relatively small area. It is generally limited to
a geographic area such as writing lab, school or building. It is generally
privately owned networks over a distance not more than 5 Km.
MAN (Metropolitan
Area Network): MAN is
the networks cover a group of nearby corporate offices or a city and might be
either private or public.
WAN (Wide Area
Network): These
are the networks spread over large distances, say across countries or even
continents through cabling or satellite uplinks are called WAN.
PAN (Personal Area
Network): A
Personal Area Network is computer network organized around an individual
person. It generally covers a range of less than 10 meters. Personal Area
Networks can be constructed with cables or wirelessly.
Network protocol
· A protocol means the rules that
are applicable for a network.
· It defines the standardized
format for data packets, techniques for detecting and correcting errors and so
on.
· A protocol is a formal
description of message formats and the rules that two or more machines must
follow to exchange those messages.
· E.g. using library books.
Types of protocols
are:
1. HTTP
2. FTP
3. TCP/IP
4. SLIP/PPP
· Hypertext Transfer
Protocol (HTTP) is a communications protocol for the transfer of information on the
intranet and the World Wide Web. HTTP is a request/response standard between a
client and a server. A client is the end-user; the server is the web site.
· FTP (File Transfer
Protocol) is the
simplest and most secure way to exchange files over the Internet. The
objectives of FTP are:
· To promote sharing of files
(computer programs and/or data).
· To encourage indirect or implicit
use of remote computers.
· To shield a user from variations
in file storage systems among different hosts.
· To transfer data reliably, and
efficiently.
· TCP/IP
(Transmission Control Protocol / Internet Protocol)
TCP - is responsible for verifying the
correct delivery of data from client to server. Data can be lost in the
intermediate network. TCP adds support to detect errors or lost data and to
trigger retransmission until the data is correctly and completely received.
IP - is responsible for moving packet
of data from node to node. IP forwards each packet based on a four byte
destination address (the IP number). The Internet authorities assign ranges of
numbers to different organizations. The organizations assign groups of their
numbers to departments. IP operates on gateway machines that move data from
department to organization to region and then around the world.
Telnet-
It is an older internet utility
that lets us log on to remote computer system. It also facilitates for terminal
emulation purpose. Terminal emulation means using a pc like a mainframe
computer through networking.
Wireless/Mobile
Computing
Wireless communication is simply
data communication without the use of landlines. Mobile computing means that
the computing device is not continuously connected to the base or central
network.
1. GSM(Global
System for Mobile communication): it is leading digital cellular system. In covered areas, cell phone users
can buy one phone that will work any where the standard is supported. It uses
narrowband TDMA, which allows eight simultaneous calls on the same radio
frequency.
2. CDMA(Code
Division Multiple Access): it is a digital cellular technology that uses spreadspectrum techniques.
CDMA does not assign a specific frequency to each user. Instead ,every channel
uses the full available spectrum.
3. WLL(Wireless
in Local Loop) : WLL is
a system that connects subscribers to the public switched telephone network
using radio signals as a substitute for other connecting media.
4. Email(Electronic
Mail): Email
is sending and receiving messages by computer.
5. Chat: Online textual talk in real time
, is called Chatting.
6. Video
Conferencing: a two way videophone conversation among multiple participants is called
video conferencing.
7. SMS(Short
Message Service): SMS is
the transmission of short text messages to and from a mobile pone, fax machine
and or IP address.
8. 3G and EDGE: 3G is a specification for the
third generation of mobile communication of mobile communication technology. 3G
promises increased bandwidth, up to 384 Kbps when a device is stationary.
EDGE(Enhanced Data
rates for Global Evolution ) is a radio based high speed mobile data standard.
Network Security Concepts:
Viruses: Viruses are programs which
replicate and attach to other programs in order to corrupt the executable
codes. Virus enters the computer system through an external source and become
destructive.
Worms: Worms are also self- replicating
programs that do not create multiple copies of itself on one computer but
propagate through the computer network. Worms log on to computer systems using
the username and passwords and exploit the system.
Trojan horse: - Though it is a useful program,
however, a cracker can use it to intrude the computer system in order to
exploit the resources. Such a program can also enter into the computer through
an email or free programs downloaded through the Internet.
Spams: Unwanted e-mail (usually of a
commercial nature sent out in bulk)
Cookies: Cookies are the text messages
sent by a web server to the web browser primarily for identifying the user.
Firewall: A firewall is used to control the
traffic between computer networks. It intercepts the packets between the
computer networks and allows only authorized packets to pass.
Cyber Law: Cyber law refers to all the
legal and regulatory aspects of Internet and the World Wide Web.
Cyber Crimes: Cyber crime involves the usage
of the computer system and the computer network for criminal activity.
Hacking: Hacking is an unauthorized
access to computer in order to exploit the resources.
Web Services:
WWW: The World Wide Web or W3 or
simply the Web is a collection of linked documents or pages, stored on millions
of computers and distributed across the Internet.
HTML (Hyper Text
Markup Language):- HTML is a computer language that describes the structure and behavior of a
web page. This language is used to create web pages.
XML (eXtensible
Markup Language):- Extensible Markup Language (XML) is a meta language that helps to describe
the markup language.
HTTP (Hyper Text
Transfer Protocol):- A protocol to transfer hypertext requests and information between servers
and browsers.
Domain Names: A
domain name is a unique name that identifies a particular website and
represents the name of the server where the web pages reside.
URL:- The Uniform Resource Locator is a means to locate resources such as web
pages on the Internet. URL is also a method to address the web pages on the
Internet. There are two types of URL, namely, absolute URL and relative URL.
Website: A collection of related web pages stored on a web
server is known as a website.
Web browser: A software application that enables to browse, search
and collect information from the Web is known as Web browser.
Web Servers: The web pages on the Internet are stored on the
computers that are connected to the Internet. These computers are known as web
servers.
Web Hosting: - Web Hosting or website hosting is the service to
host, store and maintain the websites on the World Wide Web.
Web Scripting: - The process of creating and embedding scripts in a
web page is known as Web Scripting. Types of Scripts:-
(i) Client
Side Scripts: - Client side
scripts supports interaction within a webpage. E.g. VB Script, Java Script, PHP
(PHP‟S Hypertext Preprocessor).
(ii) Server
Side Scripts: - Server side
scripting supports execution at server – end. E.g. ASP, JSP, PHP
OPEN SOURCE TERMINOLOGIES
n Free Software: The S/W’s is freely accessible and can be freely used
changed improved copied and distributed by all and payments are needed to make
for free S/W.
n Open Source Software: S/w whose source code
is available to the customer and it can be modified and redistributed without
any limitation .OSS may come free of cost but nominal charges has to pay
nominal charges (Support of S/W and development of S/W).
n FLOSS (Free Libre and Open Source Software) : S/w which is free as
well as open source S/W. ( Free S/W + Open Source S/W).
n GNU (GNU’s Not Unix) : GNU project emphasize on the freedom and its objective
is to create a system compatible to UNIX but not identical with it.
n FSF (Free Software Foundation) : FSF is a non –profit
organization created for the purpose of the free s/w movement. Organization
funded many s/w developers to write free software.
n OSI (Open Source Initiative) : Open source software organization dedicated to cause of
promoting open source software it specified the criteria of OSS and its source
code is not freely available.
n W3C(World Wide Web Consortium) : W3C is responsible
for producing the software standards for World Wide Web.
n Proprietary Software: Proprietary Software is the s/w
that is neither open nor freely available, normally the source code of the
Proprietary Software is not available but further distribution and modification
is possible by special permission by the supplier.
n Freeware: Freeware are the software freely available , which
permit redistribution but not modification (and their source code is not
available). Freeware is distributed in Binary Form (ready to run)
without any licensing fees.
n Shareware: Software for which license fee is payable after some
time limit, its source code is not available and modification to the software
are not allowed.
n Localization: localization refers to the adaptation of language,
content and design to reflect local cultural sensitivities .e.g. Software
Localization: where messages that a program presents to the user need to be
translated into various languages.
n Internationalization: Opposite of localization.
OPEN SOURCE / FREE SOFTWARE
n Linux : Linux is a famous
computer operating system . popular Linux server set of program – LAMP(Linux,
Apache, MySQL, PHP)
n Mozilla : Mozilla is a free
internet software that includes
· a web browser
· an email client
· an HTML editor
· IRC client
n Apache server: Apache web server is
an open source web server available for many platforms such as BSD, Linux, and
Microsoft Windows etc.
· Apache Web server is
maintained by open community of developers of Apache software foundation.
n MYSQL : MYSQL is one of the
most popular open source database system. Features of MYSQl :
· Multithreading
· Multi –User
· SQl Relational
Database Server
· Works in many
different platform
n PostgreSQL : Postgres SQL is a
free software object relational database server . PostgresSQL can be downloaded
from www.postgressql.org.
n Pango : Pango project is to
provide an open source framework for the layout and rendering of
internationalized text into GTK + GNOME environment.Pango using Unicode for all
of its encoding ,and will eventually support output in all the worlds major
languages.
n OpenOffice : OpenOffice is an
office applications suite. It is intended to compatible and directly complete
with Microsoft office.
OOo Version 1.1
includes:
· Writer (word processor)
· Calc(spreadsheet)
· Draw(graphics
program)etc
n Tomcat : Tomcat functions as a
servlet container. Tomcat implements the servlet and the JavaServer Pages
.Tomcat comes with the jasper compiler that complies JSPs into servlets.
n PHP(Hypertext Preprocessor)
: PHP is a widely used
open source programming language for server side application and developing web
content.
n Python: Python is an interactive
programming language originally as scripting language for Amoeba OS capable of
making system calls.
n Cloud computing is
the delivery of computing as a service rather than a product, whereby shared
resources, software, and information are provided to computers and other
devices as a utility (like the electricity grid) over a network (typically the
Internet). Clouds can be classified as public, private or hybrid.
Tips to solve Questions based on Networking
1. Where Server
should be placed: Server should be placed in the building where the number of computers is maximum.
2. Suggest a
suitable cable layout of connection: A suitable cable layout can be suggested in the
following two ways:-
(i) On the Basis of
Server: First the location of the Server
is found out. Server is placed in that building where the number of computers
are maximum (According to 80 – 20 rule). After finding the server position,
each building distance is compared with the Server building directly or
indirectly (taking other building in between). The shortest distance is counted
whether it is through directly or indirectly.
(ii) On the Basis
of Distance from each building: The distance between the each building is compared to all other buildings
either directly or indirectly. The shortest distance is counted whether it is
directly or through some other building.
3. Where the
following devices be placed:
(i) MODEM:-
(ii) HUB / SWITCH:- In all the wings
(iii) BRIDGE:
(iv) REPEATER: It is used if the distances
higher than 70 m. It regenerates data and voice signals.
(v) ROUTER: When one LAN will be connected
to the other LAN.
1 and 2 Marks Questions
1.
What do you mean by a computer network?
Ans:- Computer network is an interconnection of
autonomous computers connected together using
transmission media.
2.
What is the need for networking the computers?
Ans:- 1. Sharing of
Information, 2. Reliability, 3. Reduces cost 4. Time saving
3.
What is the full form of ARPANET?
Ans:- Advanced Research Projects
Agency Network
4.
What are various data transmission modes?
Ans:- There are three modes of
data transmission
·
Simplex
·
Half-duplex
·
Full-duplex
5.
What is the difference between Simplex and half duplex transmission?
Ans:- In simples transmission mode, the data can be
transferred in only one direction where as in half duplex transmission mode,
the data can be transmitted in both directions but one at a time.
6.
What do you mean by MODEM?
Ans:- MODEM stands for MODulatorDEModuator. It is a
device that can convert an analog signal into
digital signal and vice versa.
7.
Define the terms Bandwidth.
Ans:- Bandwidth is the range of frequencies that is
available for the transmission of data. Wider the bandwidth of a communication
channel, the more data it can transmit in a given period of time.
8.
What are various types of
transmission media?
Ans:- There are two broad
categories of transmission media
· Guided media
· Unguided Media
9.
Explain in brief the advantages and
disadvantages of Twisted pair Cable.
Ans:- Advantages
·
Inexpensive
·
Often available in existing phone system
·
Well tested and east to get
Disadvantages
·
Susceptible to noise (sound, energy etc.)
·
Not as durable as coaxial cable
·
Does not support high speed
10.
What do you mean by communication
protocol?
Ans:- A protocol is a set of rules to enable computers
to connect with one another and to exchange information with minimum possible
error.
11.
List various functions of Communication
protocol.
Ans:- Data sequencing, Data Formatting, Flow control,
Error Control,Connection Establishment and termination,Data Security
12.
List commonly used protocols.
Ans:- HTTP, TCT/IP, FTP, SLIP,
PPP, SMTP, POP, ICMP
13.
What are the main functions of TCP
Ans:- The TCP does the following
activities
·
It breaks the data into packets that the network
·
Verifies that all the packets arrived at the destination
·
Reassembles the data
14.
What do you mean by network
topology?
Ans:- Topology is how the
nodes/computers are interconnected together.
15.
List various types of Networks.
Ans:- LAN, MAN, WAN
16.
Give names of various networking
topologies in LAN.
Ans:- 1.Star Topology, 2.Ring
topology, 3.Bus topology 4.Mesh Topology
17.
Write two advantages and two
disadvantages of STAR topology.
Ans:- Advantages of STAR topology
·
It is easy to modify and add new computers to a star network without
disturbing the rest of the network.
·
Troubleshooting a star topology network is easy
Disadvantages
·
All the nodes are dependent on the central system. Hub. Failure of hub
result in shutting down of whole of the system
·
Long cable length is required
18.
What is NFS?
Ans:- NFS stands for Network File
System. NFS is a protocol that allows a set of computers to access each others
files.
19. What are the characteristics of
cloud computing?
Ans. Cloud computing exhibits the following key
characteristics:
(1)
Agility- improves with users' ability to re-provision technological
infrastructure resources.
(2)
Application programming interface (API) accessibility to software that
enables machines to interact with cloud software in the same way that a
traditional user interface (e.g., a computer desktop) facilitates interaction
between humans and computers. Cloud computing systems typically use
Representational State Transfer (REST)-based APIs.
(3)
Cost: cloud providers claim that computing costs reduce. A public-cloud
delivery model converts capital expenditure to operational expenditure. This
purportedly lowers barriers to entry, as infrastructure is typically provided
by a third party and does not need to be purchased for one-time or infrequent
intensive computing tasks.
(4)
Device and location independence enable users to access systems using a web
browser regardless of their location or what device they use (e.g., PC, mobile
phone). As infrastructure is off-site (typically provided by a third-party) and
accessed via the Internet, users can connect from anywhere.
(5)
Maintenance of cloud computing applications is easier, because they do not
need to be installed on each user's computer and can be accessed from different
places.
4 Marks Questions : Communication and Network Concepts
1. Knowledge
Supplement Organization has set up its new centre at Manglore for its office
and web based activities. It has four buildings as shown in the diagram below:
 |
|||||
Center
to center distance between various buildings Number
of Computers
|
Alpha to Beta
|
50m
|
|
Alpha
|
25
|
|
Beta to Gamma
|
150m
|
|
Beta
|
50
|
|
Gamma to Lambda
|
25m
|
|
Gamma
|
125
|
|
Alpha to Lambda
|
170m
|
|
Lambda
|
10
|
|
Beta to Lambda
|
125m
|
|
|
|
|
Alpha to Gamma
|
90m
|
|
|
|
i)
Suggest a cable layout of connections between the buildings
ii)
Suggest the most suitable place(i.e building) to house the server
of this organization with a suitable reason.
iii)
Suggest the placement of the following devices with justification:
i. Repeater
ii. Hub/Switch
iv)
The organization is planning to link its front office situated in
the city in a hilly region where cable connection is not feasible, suggest an
economic way to connect it with reasonably high speed?
2. BHARATH ELECTRONICS
COMPANY in Coimbatore is setting up the network
between its different departments located in different blocks. There are 4
blocks named as Meera (M), Tagore (T), Kalidas (K) and Bharathi (B).
Distances between
various blocks are given below:
|
Block B to Block K
|
100 m
|
|
Block B to Block M
|
200 m
|
|
Block B to Block T
|
400 m
|
|
Block K to Block M
|
300 m
|
|
Block M to Block P
|
100m
|
|
Block R to Block P
|
450 m
|
- Number
of Computers:
|
Block M
|
15
|
|
Block R
|
100
|
|
Block A
|
50
|
|
Block P
|
150
|
- Suggest
a suitable Topology for networking the computers of all Blocks.
- Name
the Block where the Server is to be installed. Justify your answer.
- Suggest
the placement of Hub/Switch in the network.
- Mention
an economic technology to provide Internet accessibility to allBlocks.
3. if “Kanganalay
Cosmetics” is planning to start their offices in four major cities in Uttar
Pradesh to provide cosmetic product support in its retail fields. The company
has planned to set up their offices in Lucknow at three different locations and
have named them as “Head office”, “Sales
office”, & “Prod office”. The company’s regional offices are located
at Varanasi, Kanpur & Saharanpur. A
rough layout of the same is as follows :
An
approximate distance between these offices as per network survey team is as
follows:
|
Place from
|
Place
to
|
Distance
|
|
Head office
|
Sales office
|
15 KM
|
|
Head office
|
Prod office
|
8 KM
|
|
Head office
|
Varanasi Office
|
295 KM
|
|
Head office
|
Kanpur Office
|
195 KM
|
|
Head office
|
Saharanpur office
|
408 KM
|
Number
of computers :
|
Head office
|
156
|
|
Sales
office
|
25
|
|
Prod office
|
56
|
|
Varanasi
Office
|
85
|
|
Kanpur
Office
|
107
|
|
Saharanpur
office
|
105
|
i)
Suggest
the placement of the repeater with justification. Name
the branch where the server should be installed. Justify your answer.
ii)
Suggest
the device
to be procured by the company for connecting all the computers within
each of its offices out of the following devices:
·
Modem
·
Telephone
·
Switch/Hub
iv) The company is planning to link
its head office situated in Lucknow with the office at Saharanpur. Suggest an
economic way to connect it; the company is ready to compromise on the speed of
connectivity. Justify your answer.
4. Dr. Rizvi Education Society of India
is starting its new CBSE School in Mumbai (Maharashtra). The society is already
running a School in Jaunpur (UP) named Dr. Rizvi Learners’ Academy, having 3
major buildings in 2 km area campus. As a network expert you need to suggest
the network plan as per E1 to E4:
Wire Distance Between Various
Buildings:
|
Library building to Admin building
|
90m
|
|
Library building to Academic building
|
80m
|
|
Academic building to Admin building
|
15m
|
|
Jaunpur School to Mumbai School
|
1350km
|
Expected number of Computers to be
installed in various buildings:
|
Library Building
|
20
|
|
Academic building
|
150
|
|
Admin building
|
35
|
|
Mumbai School
|
5
|
E1. Suggest
the cable layout among various buildings inside school campus for connecting
the buildings.
E2. Suggest the most suitable place to house
the server of the school with a suitable reason.
E3. Suggest
an efficient device from the following to be installed in each of the building
to connect all the computers:
(i)
Bridge (ii) Repeater (iii) Switch
E4. Suggest
the most suitable service (very high speed) to provide data connectivity
between Rizvi Learners’ in Jaunpur and Mumbai CBSE School from the options
HIGHER ORDER THINKING QUESTIONS
Q.1 What is protocol? How many
types of protocols are there?
Ans. When computers communicate
each other, there needs to be a common set of rules and instructions that each
computer follows. A specific set of communication rules is called a protocol.
Some protocol: PPP, HTTP, SLIP, FTP, TCP/IP
Q.2 What is the difference
between Networking and Remote Networking?
Ans. The main difference between
Networking and Remote Networking, is the network which we use in offices or
other places locally such LAN or INTERNET and remote networking is one which we
use TERMINAL Services to communicate with the remote users such WAN.
Q.3 What is point-to-point
protocol?
Ans. A communication protocol
used to connect computer to remote networking services include Internet Service
Providers. In networking, the Point-to-Point protocol is commonly used to
establish a direct connection between two nodes. Its primary use has been to
connect computers using a phone line.
Q.4 How gateway is different from
router?
Ans. A gateway operates at the
upper levels of the OSI model and translates information between two completely
different network architectures. Routers allow different networks to
communicate with each other. They forward packets from one network to another
based on network layer information. A gateway can interpret and translate the
different protocols that are used on two distinct networks. Unlike routers that
successfully connect networks with protocols that are similar, a gateway
perform an application layer conversion of information from one protocol stack
to another.
Q.5 What is the role of network
administrator?
Ans. Basic tasks for which a
network administrator may be responsible:
· Setting up and configuring
network hardware and software.
· Installing and configuring
network media and connections.
· Connecting user nodes and
peripherals of all kinds to the network.
· Adding users to and removing
users from the network.
· Managing user account.
· Ensuring the security of the
network.
· Provide training to the users to
utilize the network’s resources.
Q.6 What is the difference
between baseband and broadband transmission?
Ans. Baseband is a bi-directional
transmission while broadband is a unidirectional transmission.
No Frequency division
multiplexing possible in base band but possible in broadband.
|
SNo
|
Baseband
|
Broadband
|
|
1
|
Entire bandwidth of the cable
is consumed
by a signal
|
Broadband transmission, signals
are sent on multiple frequencies, allowing multiple signals to be sent
simultaneously.
|
|
2
|
Digital signals
|
Analog signals
|
|
3
|
bi-directional transmission
|
unidirectional transmission
|
|
4
|
No Frequency division multiplexing
possible
|
Frequency division multiplexing
possible
|
|
5
|
Uses for short distance
|
Uses for long distance
|
Q.7 What are the difference
between domain and workgroup?
Ans.
|
SNo
|
Domain
|
Workgroup
|
|
1
|
One or more computers are
servers
|
All Computers are peers.
|
|
2
|
If you have a user account on
the domain, you can logon to any computer on the domain.
|
Each computer has a set of
accounts.
|
|
3
|
There can be 100+ computers
|
Typically not more then 20-30
computers
|
|
4
|
The computers can be on
different local
network
|
All computers must be on the
same local network.
|
Q.8 what is the differences
between POP3 and IMAP Mail Server?
Ans. IMAP is a standard protocol
for accessing e-mail from a local server. A simpler e-mail protocol is Post
Office Protocol 3 (POP3), which download mail to the computer and does not
maintain the mail on the server. IMAP, e-mails are stored on the server, while
in POP3, the messages are transferred to the client’s computer when they are
read.
Q.9 Name different layer of the
ISO OSI Model.
Ans. International Standard
Orrganisation – Open Systems Interconnection has seven layers; Physical
Layer,Data Link Layer,Network Layer,Transport Layer,Session Layer,Presentation
Layer Application Layer
Q.10 What is client server
architecture?
Ans. To designated a particular
node which is well known and fixed address, to provide a service to the network
as a whole. The node providing the service is known as the server and the nodes
that use that services are called clients of that server. This type of network
is called Client-Server Architecture.
Q.11 What is FDM? Give example.
Ans. FDM-Frequency Division
Multiplexing is used in analog transmission. It is often used in short
distance. It is code transparent and any terminal of the same speed can use the
same sub-channel after the sub-channel is established. The best example if FDM
is the way we receive various stations in a radio.
Q.12 Describe the following in
brief:
i) MOSAIC ii) USENET iii) WAIS
Ans. i) MOSAIC: is the program
for cruising the internet. The National centre wrote this program for Super
Computer application at the university of Illinois. It has a simple window
interface, which creates useful hypertext links that automatically perform some
of the menu bar and button functions.
ii) USENET: is the way to meet
people and share information. Usenet newsgroup is a special group set up by
people who want to share common interests ranging from current topic to
cultural heritages.
iii) WAIS: is a WIDE AREA
INFORMATION SERVER.
