Informatics Practices Class 12 Important Questions Chapter 1 Computer Networking

 

Informatics Practices Class 12 Important Questions Chapter 1 Computer Networking

1 Mark Questions

Question 1.
Why is a switch called an intelligent hub? (All India 2014, Delhi 2012C)
Answer:
A switch is called an intelligent hub because before simply forwarding a packet it checks for the intended destination for the packet and forwards it to that destination only, this is called packet filtering. While a hub forwards a packet to all the workstations in a network but only destination computer keeps it, rest all the computers drops that packet.

Question 2.
What is the use of Repeater in a network? (All India 2014)
Answer:
In a network, repeater receives a weak signal coming from a source an amplifies it to its original strength and then again forwards it to the destination. Basically, repeater is used in a network so that a signal can travel longer distances.

Question 3.
State two advantages of networking computers instead of having standalone computers. (Delhi 2014)
Answer:
The two advantages of networking computers instead of standalone computers are:

• Communicating with each other becomes easier.
• Shared resources.

Question 4.
What is the purpose of switch in a network? (Delhi 2014)
Answer:
A switch is a networking device which is used to connect different LAN segments of a network. A switch also supports packet filtering and forwarding between LAN segments.

Question 5.
Expand
(i) 0DF
(ii) HTTP (All India 2014C)
Answer:
(i) Open Distributed Processing
(ii) HyperText Transfer Protocol

Question 6.
How is a Trojan Horse harmful to a network? (All India 2014C)
Answer:
Trojan horse like a virus or worm. At the backend, these perform some malicious activities like upload (send) some security files and information from the computer and at the same time download some unwanted files onto the computer.

Question 7.
Write one advantage each of star and bus topology used in networking. (All India 2014C)
Answer:
Advantage of star topology is that it is most reliable as there is a direct connection of every node with the central node or server.
Advantage of bus topology is that all nodes are connected through a single length of a cable so very short cable langth is used.

Question 8.
Write the name of the most suitable wireless communication channels for each of the following situations.
(i) Communication between two offices in two different countries.
(ii) To transfer the data from one mobile phone to another. (Delhi 2013)
Answer:
(i) Satellite Communication
(ii) Bluetooth or infrared whichever is supported by the phone.

Question 9.
Mr. Chandervardhan is not able to identify the Domain Name in the given URL. Identify and write it for him.
http.//www.cbsenic.in/aboutus.htm (HOTS, Delhi 2013)
Answer:
Domain in http://www.cbsenic.in/aboutus.htm is “www.cbsenic.in”.

Question 10.
Gyan Deep International School is planning to connect all computers, each spread over a distance within 40 m. Suggest an economical cable type having high-speed data transfer, which can be used to connect these computers. (Delhi 2012)
Answer:
The economical cable with high-speed data transfer can be co-axial cable.

Question 11.
Name any two most popularly used search engines. (Delhi 2012; All India 2012)
Answer:
Two most popular search engines are google and grotel.

(url:http://www.google.com and http://grotel.com)

Question 12.
Raj Kamal International School is planning to connect all computers, each spread over distance within 45 m. Suggest an economical cable type having high speed data transfer, which can be used to connect these computers. (All India 2012)
Answer:
The economical cable with high speed data transfer can be co-axial cable.

Question 13.
Which communication channel is suitable when very fast communication between two offices in two different countries is required? (Delhi 2012c)
Answer:
For very fast communication between two countries, satellite communication is suitable.

Question 14.
Given below two addresses
(i) 59.177.134.72
(ii) http://www.ccc.nic.in/welcome.htm
Identify which one of the above is an IP address and which one is a URL? (Delhi 2012c,• HOTS)
Answer:
(i) IP Address 59.177.134.72
(ii) URL http://www.ccc.nic.in/welcome.htm

Question 15.
Mr. Taufiq Ahmad wants to prevent unauthorised access to/from his company’s local area network. Write the name of system (software/hardware), which he should install.
(Delhi 2011)
Answer:
He should install firewall system to prevent unauthorised access.

Question 16.
Beauty Lines Fashion Inc. is a fashion company with design unit and market unit 135 m away from each other. The company recently connected their LANs using Ethernet cable to share the stock related information. But after joining their LANs, they are not able to share the information due to loss of signal in between. Which device out of the following should you suggest to be installed for a smooth communication?
(i) UPS
(ii)Modem
(iii) Repeater (Delhi 2011)
Answer:
(iii) Repeater.

Question 17.
Which of the following is not a feature of networking?
(i) Resource sharing
(ii) Uninterrupted Power Supply (UPS)
(iii) Reduced cost
(iv) Reliability (Delhi 2011; All India 2011; HOTS)
Answer:
(ii) Uninterrupted Power Supply (UPS).

Question 18.
Mr. Kant Sen Gupta wants to prevent unauthorised access to/from his company’s local area network. Write the name of a system (software/hardware), which he should install to do the same. (All India 2011)
Answer:
Mr. Kant should install firewall system to prevent unauthorised access.

Question 19.
Seven Brothers Fashion Inc. is a fashion company with design and market unit 130 m away from each other. The company recently connected their LANs using Ethernet cable to share stock related information. But after joining the LAN, they are not able to share the information due to loss of signal in between. Which device out of the following should you suggest to be installed for smooth communication?
(i) Modem
(ii) Repeater
(iii) UPS (All India 2011)
Answer:
(ii) Repeater

Question 20.
What is the difference between star topology and bus topology of network? (Delhi 2009; HOTS)
Answer:
In star topology, all nodes are directly connected with the central node or server, whereas in bus topology, there is a single length of transmission medium (usually co-axial cable), on which various nodes are attached and the server can be any where in this transmission cable. Both ends of the cable are closed by a terminator.

Question 21.
What is a protocol? Which protocol is used to search information from Internet using an Internet browser? (Delhi2009)
OR
What is a protocol? Which protocol is used to copy a file from/to a remotely located server? (All India 2009)
Answer:
Protocol refers to the rules which are applicable for a network. These protocols define the standardised format for data packets to be transmitted over the network, techniques for detecting errors and correcting them etc.
The protocol used to search the information from Internet using browser is HyperText Transfer Protocol (HTTP).

Question 22.
What is the difference between LAN and WAN? (All India 2009)
Answer:
A Local Area Network (LAN) is a network which is spread over a small area such as a school, office or factory. Whereas a Wide Area Network (WAN) is a network which is spread over entire world. A Wide Area Network can include a group of . LANs connected together.

Question 23.
Expand the following abbreviations
(i) HTTP
(ii) ARPANET (All India 2009)
Answer:
(i) HyperText Transfer Protocol.
(ii) Advanced Research Project Agency Network.

Question 24.
How are co-axial cable different from optical fiber? (Delhi 2008; HOTS)
Answer:
A coaxial cable consists of a solid core wire surrounded by foil or wire shield each separated by some plastic insulator. The inner core wire carries the signals and the outer wire shield provides the ground.

Whereas an optical fiber consists of a thin glass or plastic strands, which are capable of carrying light signals from a source at one end to another end.

Question 25.
What is a modem? (All India 2008)
Answer:
Modem stands for Modulator/Demodulator which converts analog signals into digital signals and vice-versa. It is used to connect the computers and transmit data using telephone lines.

Question 26.
How is a hacker different from a cracker? (All India 2008)
Answer:
A hacker is a person who is interested in gaining knowledge about the computer system and gaining unauthorised access to computer systems for playful pranks. Whereas crackers are the programmers with malicious mentality who break into secured system for the purpose of stealing and corrupting data.

Question 27.
What is the significance of cyberlaw?
Answer:
Cyber law is related to all legal and regulatory aspects of Internet and the world wide web. Anything concerned with or emanating from any legal aspects among the users of Internet and other people in cyberspace comes within the ambit of cyber law. Cyber law works as a regulatory mechanism for the electronic commerce.

Question 28.
Write one advantage of star topology as compared to bus topology.
Answer:
In star topology, there is direct connection of each node with the server, so whenever there is a communication problem with one node, other nodes are not affected.

Whereas in bus topology, all nodes are connected through a single length of line so whenever there is communication problem any where in the network entire network stops functioning.

Question 29.
Name two transmission media for networking.
Answer:
Two transmission media of networking are as follows:
(i) Co-axial cable
(ii) Optical fibre.

Question 30.
Differentiate between hacker and cracker.
Answer:
A hacker is a person who is interested in gaining knowledge about the computer system and gaining unauthorised access to computer systems for playful pranks. Whereas crackers are the programmers with malicious mentality who break into secured system for the purpose of stealing and corrupting data.

Question 31.
Compare optical fiber and co-axial transmission media.
Answer:
A coaxial cable consists of a solid core wire surrounded by foil or wire shield each separated by some plastic insulator. The inner core wire carries the signals and the outer wire shield provides the ground.

Whereas an optical fibre consists of a thin glass or plastic strands, which are capable of carrying light signals from a source at one end to another end.

Question 32.
Expand the following terminologies
(i) HTML
(ii) GSM
Answer:
(i) HyperText Markup Language.
(ii) Global System for Mobile Communication.

Question 33.
What do you understand by the terms cookies and firewall?
Answer:
The firewall is a system designed to prevent the unauthorised access to or from a private network. The firewall can be implemented in the form of software or hardware or a combination of both.

Cookies also known as browser cookies or tracking cookies, cookies are small often encrypted text files, located in browser directories. Cookies are created when a user’s browser loads a particular website. The website sends information to the browser which then creates a text file.

Question 34.
Write two advantages and two disadvantages of star topology.
Answer:
Advantages of star topology
(i) The star topology is the most reliable as there is a direct connection of every node in the network with the central node of the server.
(ii) In case, there is any problem in connection with any node, other nodes in the network are not affected.
Disadvantages of star topology
(i) Since, every node is directly connected with the central node or server, so a large quantity of cable is required.
(ii) There is dependency on the central node. If there are some problems with the central node, entire network stops functioning.

Question 35.
Write one difference between co-axial cable and optical fiber cable.
Answer:
A coaxial cable consists of a solid core wire surrounded by foil or wire shield each separated by some plastic insulator. The inner core wire carries the signals and the outer wire shield provides the ground.

Whereas an optical fiber consists of a thin glass or plastic strands, which are capable of carrying light signals from a source at one end to another end.

Question 36.
What do you understand by the term E-mail and SMS?
Answer:
E-Mail
E-mail stands for Electronic Mail. It is a text message that may contain files, images or other attachment sent through a network to a specified individual or group of individuals. Some early e-mail systems required that the sender and the recipient both be online at the same time, in common with instant messaging. Today’s e-mail systems are based on a store and forward model. E-mail servers accept, forward, deliver and store messages.

Neither the user nor their computers are required to be online simultaneously; they need to connect an e-mail server, for as long as it takes to send or receive messages. Interaction between e-mail server and clients are governed by e-mail protocol. The two most common e-mail protocols are POP3 and SMTP.

SMS
SMS stands for Short Message Service. Short text messages are transmitted to and from a mobile phone, fax machine, etc. Message must not be longer than 160 alpha-numeric characters and may also contain images or graphics. Once a message is sent, it is received by a Short Message Service Centre (SMSC), which must get to the appropriate mobile device. To do this, the SMSC sends a SMS request to Home Location Register (HLR) to find the roaming customer. Once the HLR receives the request, it will respond to the SMSC with the subscriber’s status

• Inactive or active.
• Where subscriber is in roaming.

If the response is ‘inactive’, then the SMSC will hold on to the message for a period of time. When the subscriber access his device, the HLR sends a SMS notification to the SMSC and the SMSC will attempt delivery.

The system pages the device and if it responds, the message gets delivered. The SMSC receives a verification, that the message was received by the end user, then it is categorised as, send message and will not attempt to send again.

2 Marks Questions

Question 37.
Identify the following devices:
(i) Devices that are used to connect different types of networks. It performs the necessary translation so that the connected networks can communicate properly.
(ii) A device that converts data from digital bit stream into an analog signal and vice-versa. (All India 2014)
Answer:
(i) Router
(ii) Modem

Question 38.
Write one advantage and one disadvantage of using optical fiber cable. (All India 2014)
Answer:
Advantage of using optical fiber cable It is immune to electrical and magnetic interference i.e. noise in any form because the information travels on a modulated light beam. Disadvantage of using optical fiber cable Connecting either two fibers together or a light source to a fiber is a difficult process.

Question 39.
Identify the following devices:
(i) An intelligent device that connects several nodes to form a network and redirects the received information only to intended node(s).
(ii) A device that regenerates (amplifies) the received signal and re-transmits it to its destination. (Delhi 2014)
Answer:
(i) Switch
(ii) Repeater

Question 40.
What is the name of the network topology in which each node is connected independently using a switch? (Delhi 2014)
Answer:
Star topology

Question 41.
What is meant by “Denial of Service” with reference to Internet service? (Delhi 2014)
Answer:
Denial of Service It is a type of attack in which a machine or network resource is made unavailable to the intended users. DOS attacks generally do not allow the attacker to access or modify information on the computer system or in the physical world.
The different forms of Denial of Service attacks are as follows:

• Denial of Access to Information
• Deinal of Access to Communications
• Deinal of Access to Systems
• Deinal of Access to Applications

Question 42.
List two measures to secure a computer network? (All India 2014C)
Answer:
1. Denial of Service (DOS)
A denial of service attack refers to an attempt to make computer resources unavailable to the intended users. Generally, it consists of the effort of a person or a group of persons to prevent an Internet site or service from functioning efficiently or completely. It may be temporarily or infinitely.

One of the common methods of denial of service attack is to saturate the target machine with external communication requests, in such a way that either the machine can not respond properly or respond slowly that is would not send services effectively.

2. Intrusion Problem
The intrusion problem refers to the malicious activities or policy violation performed on a computer system. The main motive of intrusion is to tress vital information and essential data. Such type of activities are performed by the people having malicious mentality.

• Intrusion Detection System It is a device or software application that monitors the network for malicious activities. The intrusion detection and prevention system is primarily focused on identifying possible incidents, logging information and reporting attempts.
• Snooping It refers to unauthorised opening of files or accessing data, e-mail, etc. Snooping may include monitoring and tracing of keystrokes pressed, capturing the passwords and login information, etc.
• Eavesdropping It is identical to snooping. When there is intentional interception of other data such as e-mail, login-id, credit card information, password, etc., then it is said to be eavesdropping. In other words, when someone listens or intercepts others data secretly, then it is said to be eavesdropping.

Question 43.
What do you understand by Network Security? Name two common threats to it. (Delhi 2013)
Answer:
Network security is needed to protect data during its transmission and to guarantee that data transmission is authentic.
Two common threats are:

• Intrusion Problem.
• Denial of Service Attacks.

Question 44.
Write one advantage of star topology over bus topology and one advantage of bus topology over star topology. (Delhi 2013)
Answer:
Advantage of star topology over bus topology The star topology is the most reliable as there is a direct connection of every node in the network with the central node, so any problem in any node will affect the particular node only.

Advantage of bus topology over star topology Extension of network is very easy in bus topology, we can connect new node along its length.

Question 45.
What is MAC address? What is the difference between MAC address and an IP address? (Delhi 2013)
Answer:
MAC Address A MAC address is an essentially unique number associated with a network card in a machine. It serves as a convenient way to distinguish between two different computers. A MAC address consists of 48 bits, usually represented as a string of 12 hexadecimal digits (0 to 9, a to f or A to F); these are often grouped into pairs separated by colons or dashes, e.g. the Mac address 001B638445E6 may be given as 00:1 b:63:84:45:e6 or as 00-1B-63-84-45-E6.

IP Address Computers on the Internet need to find one another in order to communicate. Each computer, therefore, has a unique identifying number known as an IP address. Examples of IP address are 22.231.113.64 or 194.66.82.11. An IP address always has four numbers separated by dots. Each number has a value of 0 to 255.

Question 46.
Identify domain name and URL from the following: (Delhi 2012)

http://www.he1 pingeachother.1n/home/aboutus.htm

Answer:
Domain Name

www.helpingeachother. in

URL Name.

http://www.helpingeachother.in/home/ aboutus.htm

Question 47.
Give a suitable example of URL and domain name. (All India 2012)
Answer:
Domain Name

www.cbse.nic.in

URL Name

http://www.cbse.nic.in/welcome.htm

Question 48.
Give one advantage and one disadvantage of using star topology over bus topology. (Delhi 2012)
Answer:
One advantage of star topology over bus topology is that in star topology there is separate connection between the server and individual devices. That’s why failure of one node does not affect the rest of network, whereas in bus topology all the nodes are connected over a single line. Due to this, if there is a problem in communication anywhere in the network with any node, the entire network will stop functioning.

Question 49.
Give an advantage of using star topology over bus topology. Show a network layout of star topology to connect 5 computers. (All India 2012)
Answer:
Advantage of star topology over bus topology The star topology is the most reliable as there is a direct connection of every node in the network with the central node, so any problem in any node will affect the particular node only.

Advantage of bus topology over star topology Extension of network is very easy in bus topology, we can connect new node along its length.

The network layout to show a connection of five computers using star topology is as follows:

Question 50.
Mr. Kavye Shastri, General Manager of Unit Nations corporate recently discovered that the communication between his company’s accounts office and HR office is extremely slow and signals drop quite frequently. These offices are 120 m away from each other and connected by an Ethernet cable.
(i) Suggest him a device which can be installed in between the offices for smooth communication.
(ii) What type of network is formed by having this kind of connectivity out of LAN, MAN and WAN? (Delhi 2012)
Answer:
(i) The device that can be installed between the office for smooth communication is repeater.
(ii) The type of network is Local Area Network (LAN).

Question 51.
Ms. Rani sen, General Manager of Global Nations corporate recently discovered that the communication between her company’s accounts office and HR office is extremely slow and signal drop quite frequently. These offices are 125 m away from each other and connected by Ethernet cable.
(i) Suggest her a device, which can be installed in between the offices for smooth communication.
(ii) What type of network is formed by having this kind of connectivity out of LAN, MAN and WAN? (All India 2012)
Answer:
(i) The device that can be installed between the office for smooth communication is repeater.
(ii) The type of network is Local Area Network (LAN).

Question 52.
Expand the following abbreviations
(i) GSM
(ii) CDMA (Delhi 2009)
Answer:
(i) Global System for Mobile Communication
(ii) Code Division Multiple Access

Question 53.
Expand the following terms with respect to networking
(i) MODEM
(ii) WLL
(iii) FTP
(iv) TCP/IP (Delhi 2008)
Answer:
(i) Modulator-Demodulator
(ii) Wireless in Local Loop
(iii) File Transfer Protocol
(iv) Transmission Control Protocol/Internet Protocol.

Question 54.
Expand the following terms with respect to networking
(i) PPP
(ii) GSM
(iii) XML
(iv) HTTP
Answer:
(i) Point-to-Point Protocol
(ii) Global System for Mobile Communication
(iii) extensible Markup Language
(iv) HyperText Transfer Protocol.

Question 55.
Expand the following terms with respect to networking
(i) CDMA
(ii) FTP
(iii) WLL
(iv) HTML
Answer:
(i) Code Division Multiple Access
(ii) File Transfer Protocol
(iii) Wireless in Local Loop
(iv) HyperText Markup Language.

Question 56.
Expand the following terms with respect to networking
(i) XML
(ii)WWW
(iii) WLL
(iv) TCP/IP
Answer:
(i) extensible Markup Language
(ii) World Wide Web
(iii) Wireless in Local Loop
(iv) Transmission Control Protocol/Internet Protocol.

Question 57.
Expand the following terms
(i) CDMA
(ii) URL
(iii) HTTP
(iv) WAN
Answer:
(i) Code Division Multiple Access
(ii) Uniform Resource Locator
(iii) HyperText Transfer Protocol
(iv) Wide Area Network.

Question 58.
Expand the following terms
(i) XML
(ii) GSM
(iii) SMS
(iv) MAN
Answer:
(i) extensible Markup Language
(ii) Global System for Mobile Communication
(iii) Short Message Service
(iv) Metropolitan Area Network.

Question 59.
Expand the following terminologies
(i) TCP/IP
(ii) XML
(iii) CDMA
(iv) WLL
Answer:
(i) Transmission Control Protocol/Internet Protocol
(ii) extensible Markup Language
(iii) Code Division Multiple Access
(iv) Wireless in Local Loop.

4 Marks Questions

Question 60.
Freshminds University of India is starting its first campus Anna Nagar of South India with its centre admission office in Kolkata. The university has three major blocks comprising of Office Block, Science Block and Commerce Block in the 5 km area campus.

As a network expert, you need to suggest the network plan as per (i) to (iv) to the authorities keeping in mind the distance and other given parameters.

Expected wire distances between various locations:

Expected number of computers to installed at various locations in the university are as follows:

(i) Suggest the authorities, the cable layout amongst various blocks inside university campus for connecting the blocks.
(ii) Suggest the most suitable place (i.e. block) to house the server of this university with a suitable reason.
(iii) Suggest an efficient device from the following to be installed in each of the blocks to connect all the computers.
(a) Switch
(b) Modem
(c) Gateway
(iv) Suggest the most suitable (very high speed) service to provide data connectivity between Admission Office located in Anna Nagar from the following options:
(a) Telephone lines
(b) Fixed line dial-up connection
(c) Co-axial cable network
(d) GSM
(e) Leased lines
(f) Satellite connection (Delhi 2009)
Answer:
(i) The suggested cable layout amongst various blocks inside university campus for connecting the blocks will be as follow:
Using Star Network:

Using Bus Network:

(ii) The most suitable place (i.e. block) to house the server of this university is Science Block, because in this block there are maximum number of computer and according to 80-20 rule 80% of traffic should be local.
(iii) The efficient device to be installed in each of the blocks to connect all the computers is switch.
(iv) For very high-speed connectivity between Admission office located in Kolkata and the campus office in Anna Nagar is satellite connection.

Question 61.
Eduminds University of India is starting its first campus in a small town Parampur of central India with its centre admission office in Delhi. The university has three major buildings comprising of Admin Building, Academic Building and Research Building in the 5 km area campus. As a network expert, you need to suggest the network plan as per (i) to (iv) to the authorities keeping in mind the distances and other given parameters.

Expected wire distances between various locations:

Expected number of computers to be installed at various locations in the university are as follows:

(i) Suggest the authorities, the cable layout amongst various buildings inside the university campus for connecting the building.
(ii) Suggest the most suitable place (i.e. building) to house the server of this organisation, with a suitable reason.
(iii) Suggest an efficient device from the following to be installed in each of the buildings to connect all computers.
(a) Gateway
(b) Modem
(c) Switch
(iv) Suggest the most suitable (very high speed) service to provide data connectivity between Admission Building located in Delhi and the campus located in Parampur from the following options:
(a) Telephone line
(b) Fixed line dial-up connection
(c) Co-axial cable network
(d) GSM
(e) Leased line
(f) Satellite connection. (All India 2009; HOTS)
Answer:
(i) The suggested cable layout is as follows: Using Bus/Star Network

(ii) The most suitable place (i.e. block) to house the server of this university is Academic Block, because there are maximum number of computers in this block and according to 80-20 rule 80% of traffic in a network should be local.
(iii) The efficient device to be installed in each of the blocks to connect all the computers is switch.
(iv) For very high-speed connectivity between Admission Building located in Delhi and campus located in Parampur is satellite connection.

Question 62.
Bias Methodologies is planning to expand their network in India starting with three cities in India to build infrastructure for research and development of their chemical products. The company has planned to setup their main office in Pondicherry at three different locations and have named their offices as Back Office, Research Lab and Development Unit. The company has one more research office namely Corporate Unit in Mumbai. A rough layout of the same is as follows:

Approximate distance between these offices is as follows:

In continuation of the above, the company experts have planned to install the following number of computers in each of these offices.

(i) Suggest the kind of network required (out of LAN, MAN, WAN) for connection each of the following office unit
(a) Research Lab and Back Office
(b) Research Lab and Development Unit
(ii) Which of the following devices will you suggest for connecting all the computers with each of their office units?
(a) Switch/Hub
(b) Modem
(c) Telephone
(iii) Which of the following communication media, will you suggest to be procured by the company for connecting their local office units in Pondicherry for very effective (high speed) communications?
(a) Telephone cable
(b) Optical fiber
(c) Ethernet cable
(iv) Suggest a cable/wiring layout for connecting the company’s local office units located in Pondicherry. Also, suggest an effective method/technology for connecting the company’s office located in Mumbai. (Delhi 2008)
Answer:
(i) The type of network between the Research Lab and the Back Office is LAN (Local Area Network). The type of network between Research Lab and Development Unit is MAN (Metropolitan Area Network).
(ii) The suitable device for connecting all the computers within each of their office units is switch/hub.
(iii) For connecting the local office units in Pondicherry for very effective (high speed) communication is optical fiber.
(iv) The cable/wiring layout for connection is as follows:

Question 63.
China Middleton Fashion is planning to expand their network in India, starting with two cities to provide infrastructure for distribution of their products. The company has planned to setup their main office in Chennai at three different locations and have named their offices as Production Unit, Finance Unit and Media Unit. The company has its Corporate Unit in Delhi.
A rough layout of the same is as follows:

Approximate distance follows: between these units is as follows:

In continuation of the above, the company experts have planned to install the following number of computers in each of their offices

(i) Suggest the kind of network required (out of LAN, MAN, WAN) for each of the following units:
(a) Production Unit and Media Unit
(b) Production Unit and Finance Unit
(ii) Which of the following devices will you suggest for connecting all computers with each of their office units?
(a) Switch/Hub
(b) Modem
(c) Telephone
(iii) Which of the following communication media, will you suggest to be procured by the company for connecting their local office units in Chennai for very effective (high speed) communication?
(a) Telephone cable
(b) Optical fiber
(c) Ethernet cable
(iv) Suggest a cable/wiring layout for connecting the company’s local office units located in Chennai.
Also, suggest an effective method/technology for connecting the company’s office unit located in Delhi. (All India 2008)
Answer:
(i) The type of network between the Production Unit and Media Unit is MAN (Metropolitan Area Network). The type of network between Production Unit and Finance Unit is LAN (Local Area Network).
(ii) The suitable device for connecting all the computers within each of their office units is switch/hub.
(iii) For connecting the local office units in Chennai for very effective (high speed) communication is optical fiber.
(iv) The cable/wiring layout for connection is as follows:

Question 64.
Bhartiya Connectivity Association is planning to spread their offices in four major cities of India to provide regional IT infrastructure support in the field of education and culture. The company has planned to setup their head office in New Delhi in three locations and have named their New Delhi offices as Front Office, Back Office and Work Office. The company has three more regional offices as three major cities of India. A rough layout of the same is as follows:

Approximate distances between these offices as per network survey team is as follows:

In continuation of the above, the company experts have planned to install the following number of computers in each of their offices:

(i) Suggest the network type (out of LAN, MAN, WAN) for connecting each of the following set of the their offices:
(a) Back Office and Work Office
(b) Back Office and South Office
(ii) Which device will you suggest to be procured by the company for connecting all the computers with each of their offices out of the following devices?
(a) Switch/Flub
(b) Modem
(c) Telephone South Office, East Office and West Office located in other
(iii) Which of the following communication medium will you suggest to be procured by the company for connecting their local offices in New Delhi for very effective and fast communication?
(a) Telephone cable
(b) Optical fiber
(c) Ethernet cable
(iv) Suggest the cable/wiring layout for connecting the company’s local offices located in New Delhi. Also, suggest an effective method for connecting the company’s regional offices East Office, West Office and South Office with offices located in New Delhi.
Answer:
(i) The type of network between the Back Office and the Work Office is LAN (Local Area Network). The type of network between the Back Office and the South Office is WAN (Wide Area Network).
(ii) The suitable device for connecting all the computers in each of their offices is switch/hub.
(iii) For connecting local offices in New Delhi for very effective and fast communication is optical fiber.
(iv) The suggested layout for connection is as follows:

For connecting the regional offices satellite communication is effective technology.

Question 65.
Hindustan Connecting World Association is planning to start their offices in four major cities in India to provide regional IT infrastructure support in the field of education and culture. The company has planned to setup their head office in New Delhi in three different locations and have named their New Delhi offices as Sales Office, Head Office and Tech Office. The company’s regional offices are located at Coimbatore, Kolkata and Ahmedabad.
A rough layout of the same is as follow:

Approximate distances between these offices as per network survey team is as follows:

In continuation of the above, the company experts have planned to install the following number of computers in each of their offices.

(i) Suggest the network type (out of LAN, MAN, WAN) for connecting each of the following set of their offices.
(a) Head Office and Tech Office
(b) Head Office and Coimbatore Office
(ii) Which device will you suggest to be procured by the company for connecting all computers within each of their offices out of the following devices?
(a) Modem
(b) Telephone
(c) Switch/Hub
(iii) Which of the following communication media will you suggest to be procured by the company for connecting their local offices in New Delhi for very effective and fast communication?
(a) Ethernet cable
(b) Optical fiber
(c) Telephone cable
(iv) Suggest the cable/wiring layout for connecting the company’s local offices located in New Delhi. Also, suggest an effective method/technology for connecting the company’s regional offices at Kolkata, Coimbatore and Ahmedabad.
Answer:
(i) The type of network between the Head Office and Tech Office is LAN (Local Area Network).
The type of network between the Head Office and Coimbatore Office is WAN (Wide Area Network).
(ii) The suitable device for connecting all the computers in each of their offices is switch/hub.
(iii) For connecting local offices in New Delhi for very effective and fast communication is optical fiber.
(iv) The suggested layout for connection is as follows:

For connecting the regional offices satellite communication is an efficient technology.

Question 66.
University of correspondence in Allahabad is setting up the network between its different wings. There are four wings named as Science (S), Journalism (J), Arts (A) and Home science(H). Distance between various wings are given below.

Number of computers:

(i) Suggest a suitable topology for networking the computers of all wings.
(ii) Name the wing, where the server to be installed, justify your answer.
(iii) Suggest the placement of hub/switch in the network.
(iv) Mention an economic technology to provide Internet accessibility to all wings.
Answer:
(i) For connecting all the computers of all wings star topology can be used, because it is most reliable. We can also set a bus network, if economy is main factor, because it is most economical.
(ii) The server should be installed in Wing A, because there are maximum number of computers. According to 80-20 rule 80% of the traffic should be local. By installing server in Wing A, network traffic could be reduced.
(iii) The hub/switch must be placed in all the wings to connect all the computers of the network.
(iv) To provide Internet accessibility to all wings economically, we can use a proxy server in Wing A and we should connect the Internet through a dial-up network.

Question 67.
Indian Public School in Darjeeling is setting up the network between its different wings. There are four wings named as:
Senior (S), Junior (J), Admin (A) and Hostel (H) Distance between various wings are given below:

Number of computers:

(i) Suggest a suitable topology for establishing the networking of the computers of all wings.
(ii) Name the wing, where the server is to be installed. Justify your answer.
(iii) Suggest the placement of hub/switch in the network.
(iv) Mention an economic technology to provide Internet accessibility to all wings.
Answer:
(i) When reliability is the main factor star topology should be use. But when the economy is the most considerable factor. The bus topology should be used as in this topology, the requirement of cable is the least.
(ii) The server should be installed in Wing S, because in this wing there are maximum number of computers. According to 80-20 rule, ideally 80% of traffic in a network should be local. By installing server in Wing, network traffic could be reduced.
(iii) The hub/switch should be installed in all the wings to connect are the computers in the network.
(iv) To provide accessibility to Internet to all Wing S, we can use a proxy server in Wing S and then connect the Internet through a dial-up network.

Question 68.
The Great Brain Organisation has set up its new branch at Sri Nagar for its office and web-based activities. It has four wings of buildings as shown in the diagram.

Centre to centre distances between various blocks:

Number of computers:

(i) Suggest the most suitable cable layout of connections between the wings and topology.
(ii) Suggest the most suitable place (i.e. wing) to house the server of this organisation with a suitable reason, with justification.
(iii) Suggest the placement of the following devices with justification
(a) Repeater
(b) Hub/Switch
(iv) The organisation is planning to link its head office situated in New Delhi with the offices at Sri Nagar. Suggest an economic way to connect it, the company is ready to compromise on the speed of connectivity. Justify your answer.
Answer:
(i) The most suitable layout between the wings is as follows and the topology is bus topology. Because it is most economical.

(ii) The most suitable place for installing server is Wing Y. Because there are a maximum number of computers. According to 80-20 rule ideally, 80% of traffic should be local. By installing server in Wing A network traffic could be reduced.
(iii) (a) According to suggested layout of the
Network repeaters are not needed to be installed because the hub/switch installed in each wing will act as a repeater.
(b) Hub/switch is required one in each wing.
(iv) The economical way to connect head office in Delhi with offices at Sri Nagar is dial-up or broadband. Though the speed will be lesser than other methods, which are expensive.

Question 69.
The Cyber Mind Organisation has setup its new branch at Mizoram for its office and web based activites. It has four wings of buildings as shown in the diagram.

Centre to centre distances between various blocks:

Number of computers:

(i) Suggest the most suitable cable layout of connections between the wings and topology.
(ii) Suggest the most suitable place (i.e. wing) to house the server of this organisation with a suitable reason, with justification,
(iii) Suggest the placement of the following devices with justification:
(a) Repeater
(b) Hub/Switch
(iv) The organisation is planning to link its head office situated in New Delhi with the offices at Mizoram. Suggest an economic way to connect it, the company is ready to compromise on the speed of connectivity. Justify your answer.
Answer:
(i) The suitable layout for connecting the wings is as follows:

The topology used is bus topology because it is most economical.
(ii) The most suitable place to keep the server is Wing Z, because there are maximum number of computers in it. As per 80-20 rule 80% of network traffic should be local keeping server in Wing Z will reduce the network traffic.
(iii) (a) In the suggested layout, there is not
any need of repeater and the installed hub/switch with every wing will act as a repeater.
(b) The hub/switch is required to be installed with every wing.
(iv) The economical way of connecting the Head office situated in Delhi with the office at Mizoram is dial-up or broadband. But its speed of data transfer is slower than other expensive means.

Question 70.
Mention any two security issues over a network. Define domain name.
Answer:
The security issues over a network are:

1. Computer worms and viruses remain the most common security threat, which could damage the data or corrupt the files in the computer.
2. Information theft is a big concern, i.e. the theft of many delicate personal file or official files.

Question 71.
Define domain name.
Answer:
Domain Name
Domain name is a unique name or identification that helps to create the path to open a particular website. All the domain names have IP addresses. IP address can be remembered by the computer, but it is difficult to remember for a human being. If you know that URL (Uniform Resource Locator) of a website, you can access it. The URL is actually the domain name of website, so the domain name is unique name of a website. Every time we enter a domain name it will be converted into an IP address and the website will be opened,

E.g., www.Mybook.com

A domain name contains three parts:

• Hostname as, www
• Name describing the website purpose as, Mybook
• Top level domain as .com, .net, .edu, etc.

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