Computer Networks

Through Internet we can establish contact with anyone in the world.

The main function of TCP is to divide the message or data into packets of a definite size on the source computer.

Wi-Fi refers to wireless fidelity which enables us to connect to the ISP without any cable.

Web Browser is a software that enables us to access the internet and explore websites.

Web page constitutes the Website.

Web Hosting enables our website to be accessible via internet.

A Chat is a real-time communication via keyboard between two or more users over the internet.

Electronic junk mail or junk newsgroup postings are known as SPAM.

A Cookie is a text file containing a string of information which stores browsing information on the hard disk of the computer.

The first network that planted the seed of internet was ARPANET.

The protocol used for internet is TCP/IP.

A device used to connect dissimilar networks is called Gateway.

IP is responsible for handling the address of the destination computer so that each packet is delivered to its proper destination.

Plug-ins can allow a Web browser to display additional content it was not originally designed to display.

A web page which displays same kind of information whenever a user visits it is known as a Static web Page.

In Star topology, each node is connected to a central device.

To connect computers located in a specific building or campus is known as LAN.

Wi-Fi, infrared and Bluetooth are examples of Communication Channel.

Interspace is a software that allows multiple users in a client-server environment to communicate with each other to send and receive data of various types such as data files, videos, audio and textual data.

A server that provides its services to other workstations on a network is a Dedicated server.

Node refers to computers that are attached to a network and are seeking to share resources.

MAC is the physical address of the computer while IP is the logical address of the computer that uniquely identifies a computer on a network.

bits/second is the measuring unit of speed at which the data transfer takes place.

All the computers are connected with each other in an unorganized manner in Mesh topology.

In Peer-to-Peer network, all Computers share equivalent responsibility for processing data.

Switch network device is known as an intelligent hub.

A set of rules that governs internet is called protocol.

Answer

True

Reason — Protocol means a set of rules and regulations that governs a network. It represents the communication methods which are to be followed by the sending and receiving devices.

A repeater handles different protocols.

Answer

False

Reason — A repeater is a network device that amplifies a signal transmitted across the network, ensuring that the signal is received in the same way as it is sent. It operates at the physical layer of the OSI model and does not handle different protocols. On the other hand, a router operates at the network layer and is capable of handling different protocols.

A hub is known as an intelligent device on the network.

Answer

False

Reason — A hub is known as an unintelligent device on the network that simply transfers data from one port of the network to another.

A location on a net server is called a website.

Answer

True

Reason — A website is a location on a web server where users can access and interact with digital assets (web pages, images, videos, audios etc) through a web browser.

A document that uses HTTP is called a web page.

Answer

True

Reason — A document that uses the HTTP (Hypertext Transfer Protocol) to be accessed and retrieved from a web server is called a web page.

A switch is a device used to segment networks into sub-networks or subnets.

Answer

False

Reason — A router is a device used to segment networks into sub-networks or subnets, while a switch is a network device used to interconnect computers or devices on a network.

Email helps us to send and receive messages through video conferencing.

Answer

False

Reason — Email helps us to send and receive messages through text using SMTP (Simple Mail Transfer Protocol) and POP3 (Post Office Protocol 3) protocols.

In star topology, each computer is connected with the other computer.

Answer

False

Reason — In star topology, each computer is connected to a central controller called hub or switch.

Applications such as WhatsApp, Slack, Skype, Yahoo Messenger, Google Talk, Facebook Messenger, Google Hangout, etc., are examples of web browser.

Answer

False

Reason — Applications such as WhatsApp, Slack, Skype, Yahoo Messenger, Google Talk, Facebook Messenger, Google Hangout, etc., are examples of instant messengers.

A router connects a local area network to the internet.

Answer

True

Reason — A router uses IP address to connect a local area network to the internet.

A computer network:

1. Is a collection of hardware components and computers
2. Is interconnected by communication channels
3. Allows sharing of resources and information
4. All of the above

Answer

All of the above

Reason — A computer network is a collection of interconnected computers and other hardware devices using communication channels to share data and various resources, including hardware and software resources.

Which network device regenerates and retransmits a weak signal?

1. Router
2. Hub
3. Repeater
4. RJ-45

Answer

Repeater

Reason — A repeater is a network device that regenerates and retransmits weak or corrupted signals so that the signal is received in the same way as it was sent.

What is the use of Bridge in the network?

1. To connect LANs
2. To separate LANs
3. To control network speed
4. All of these

Answer

To connect LANs

Reason — Bridges are devices that connect one LAN to another LAN that uses the same protocol.

Each IP packet must contain:

1. Only Source address
2. Only Destination address
3. Source and Destination address
4. Source or Destination address

Answer

Source and Destination address

Reason — Each IP packet in a computer network must contain both the source address (the address of the sender or originator) and the destination address (the address of the intended recipient). This ensures that the packet is routed correctly through the network to reach its destination.

Which of these is not a communication channel?

1. Satellite
2. Microwave
3. Radio wave
4. Wi-Fi

Answer

Wi-Fi

Reason — Wi-Fi is not a communication channel but a technology that uses communication channels like radio waves to transmit data wirelessly over short distances. In contrast, satellite, microwave, and radio waves are specific types of communication channels used for transferring information over various distances.

MAN stands for ............... .

1. Metropolitan Area Network
2. Main Area Network
3. Metropolitan Access Network
4. Metro Access Network

Answer

Metropolitan Area Network

Reason — MAN stands for Metropolitan Area Network.

............... topology is a combination of star and bus topologies.

1. Bus
2. Tree
3. Star
4. Ring

Answer

Tree

Reason — The shape of tree topology network is that of an inverted tree with the central root branching and sub-branching to the extremities of the network.

In which topology are all the nodes connected through a single Coaxial cable?

1. Star
2. Tree
3. Bus
4. Ring

Answer

Bus

Reason — Bus topology is a multi-point configuration, i.e., several devices are connected to a main long cable (usually co-axial cable) which acts as a backbone.

Which of the following is the smallest network?

1. WAN
2. MAN
3. LAN
4. Wi-Fi

Answer

LAN

Reason — LAN is the smallest network among the options provided. It covers a small geographical area like a home, office, or school. It typically covers an area of up to 10 kilometers.

Which protocol is used for the transfer of hypertext content over the web?

1. HTML
2. HTTP
3. TCP/IP
4. FTP

Answer

HTTP

Reason — Hyper Text Transfer Protocol (HTTP) is the set of rules for transferring hypertext content on World Wide Web.

Which of the following network topologies is shown in the figure:

1. Bus
2. Star
3. Tree
4. Ring

Answer

Star

Reason — The figure shows a Star network topology where devices like computers and printers are connected directly to a central hub.

Which network device connects dissimilar networks?

1. Router
2. Gateway
3. Bridge
4. Repeater

Answer

Gateway

Reason — A gateway is a network device that connects dissimilar networks, establishes an intelligent connection between a local network and external networks with completely different structures.

Which amongst the following is not an example of browser?

1. Chrome
2. Firefox
3. Avast
4. Edge

Answer

Avast

Reason — Avast is not a web browser, it is an antivirus software. Chrome, Firefox, and Edge are examples of browsers.

For web pages where information is changed frequently, e.g., stock prices, weather information, which out of the following options would you opt for?

1. Static web page
2. Dynamic web page
3. Animated web page
4. None of these

Answer

Dynamic web page

Reason — A dynamic web page uses scripting languages to display changing content on the web page, such as stock prices and weather information.

............... is a communication methodology designed to deliver both voice and multimedia communications over Internet Protocol.

1. VoIP
2. SMTP
3. PPP
4. HTTP

Answer

VoIP

Reason — VoIP (Voice over Internet Protocol) is a communication methodology designed to deliver both voice and multimedia communications over Internet protocol.

Television cable network is an example of:

1. LAN
2. WAN
3. MAN
4. Internet

Answer

MAN

Reason — A television cable network is an example of a MAN (Metropolitan Area Network) because it covers a city or large area, typically up to 30-40 km.

Assertion (A): ARPANET was the first computer network created in the year 1969 by Advanced Research Projects Agency (ARPA) of the Pentagon, USA.

Reasoning (R): The objective of creating ARPANET was to develop a reliable communication network for the US military defence services for sending and receiving instant messages.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.

Answer

Both A and R are true and R is the correct explanation of A.

Explanation
ARPANET, jointly designed and named by the Advanced Research Projects Agency (ARPA) and the US Department of Defense (DoD), was the first computer network and came into existence in 1969. The objective of creating ARPANET was to develop a reliable communication network for the US military defense services, enabling them to send and receive instant messages and share data.

Assertion (A): Internet cookies are text files that contain small pieces of data, like a username, password and user's preferences while surfing the internet.

Reasoning (R): To make browsing the internet faster and easier, it is required to store certain information on the server's computer.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.

Answer

A is true but R is false.

Explanation
Internet cookies are small text files that contain small pieces of data such as usernames, passwords, and user preferences while surfing the internet. They are messages transmitted by a web server to a web browser, allowing the server to keep track of the user's activity on a specific website.

Assertion (A): A router is more reliable and intelligent device than a Hub or Switch.

Reasoning (R): Router has advanced capabilities as it can analyze data and decide how it is packaged and sent to other networks.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.

Answer

Both A and R are true and R is the correct explanation of A.

Explanation
A router is considered as a more reliable and intelligent device than a hub or switch because it has advanced capabilities to analyze the data being sent over a network, decide or alter how it is packaged, and send it to different computer networks.

Assertion (A): A PAN (Personal Area Network) is established within the vicinity of a room (20 to 30 sq. ft.) for sharing information among computers.

Reasoning (R): A WAN (Wide Area Network) spans thousands of kilometres and is used to establish connectivity across several countries and continents.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.

Answer

Both A and R are true but R is not the correct explanation of A.

Explanation
PANs (Personal Area Networks) are small networks used to establish communication between a computer and other devices in proximity, typically up to 10 meters (20 to 30 sq.ft.). On the other hand, a WAN (Wide Area Network) spans a large geographical area across countries and continents. A WAN can cover an area with a radius spanning hundreds of kilometers.

Assertion (A): A Repeater is a device that amplifies the network over geographical distance.

Reasoning (R): A Hub is a device which is used to connect more than one device in the network.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.

Answer

Both A and R are true but R is not the correct explanation of A.

Explanation
A repeater is a device that amplifies a signal transmitted across the network so that the signal is received in the same way it is sent. A hub is a hardware device used to connect several computers together using different ports.

Assertion (A): VoIP stands for Voice over Internet Protocol.

Reasoning (R): VoIP is a technology that allows you to make voice calls using a broadband connection instead of a regular phone line.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.

Answer

Both A and R are true and R is the correct explanation of A.

Explanation
VoIP stands for Voice over Internet Protocol, and it is a technology that allows us to make voice calls using a broadband connection instead of a regular phone line. The voice calls are first digitized, compressed, and then fragmented into small packets, which are then relayed by Internet Protocol (IP) across the network.

Assertion (A): A protocol defines the set of rules that are applicable for data sharing and communication over a network.

Reasoning (R): Local Area Network (LAN) is an example of protocol.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.

Answer

A is true but R is false.

Explanation
A protocol defines the set of rules and regulations applicable for data sharing and communication over a network. It is a formal description of message formats and the rules that devices must follow to exchange those messages. However, Local Area Network (LAN) is not an example of a protocol, rather, it is a type of computer network.

Assertion (A): A gateway is a network device that connects dissimilar networks.

Reasoning (R): A gateway establishes a connection between local network and external network.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.

Answer

Both A and R are true and R is the correct explanation of A.

Explanation
A Gateway is a network device that connects dissimilar networks. Gateway provides the necessary translation of data received from network into a format or protocol recognized by devices within the internal network establishing an intelligent connection between the two.

Rovenza Communication International (RCI) is an online corporate training provider for IT-related courses. The company is setting up their new campus in Kolkata. You, as a network expert, have to study the physical locations of various blocks and the number of computers to be installed. In the planning phase, provide the best possible answers for the queries (a) to (d) raised by them.

Block-to-Block distance (in metres):

Expected Computers to be installed in each block:

(a) Suggest the most appropriate block where RCI should plan to install the server.

(b) Suggest the most appropriate block-to-block cable layout to connect all three blocks for efficient communication.

(c) Which type of network out of the following is formed by connecting the computers of these three blocks?

1. LAN
2. MAN
3. WAN

(d) Which wireless channel out of the following should be opted by RCI to connect to students from all over the world?

1. Infrared
2. Microwave
3. Satellite

Answer

(a) The most appropriate block where RCI should plan to install the server is faculty recording block as maximum number of computers are placed there.

(b) The most appropriate block-to-block cable layout to connect all three blocks for efficient communication is shown below:

(c) LAN

Reason — The network is a Local Area Network (LAN) because it connects computers within a single campus in Kolkata, covering short distances (60m, 70m, 120m) between blocks.

(d) Satellite

Reason — RCI should use Satellite communication for global connectivity. Satellite provides worldwide coverage, enabling students from anywhere to access online corporate training and ensuring consistent, reliable communication over long distances.

University of Correspondence in Allahabad is setting up a network between its different wings. There are 4 wings named Science (S), Journalism (J), Arts (A) and Home Science (H).

Distance between various wings:

Number of Computers:

(a) Suggest the most suitable topology for networking the computers of all wings.

(b) Name the wing where the Server is to be installed. Justify your answer.

(c) Suggest the placement of Hub/Switch in the network.

(d) Mention how economic technology will provide Internet accessibility to all wings.

Answer

(a) The most suitable topology is star topology to connect the computers of all wings.

(b) The server should be installed in Wing A because Wing A has the highest number of computers (150), and this will help reduce network traffic.

(c) The Hub/Switch or should be placed in all the wings.

(d) The economic way to provide internet accessibility to all the wings is to use the proxy server at Wing A and connect to the internet through a dial-up network.

Perfect Edu. Services Ltd. is an educational organization. It is planning to set up its India campus at Chennai with its head office at Delhi. The Chennai campus has four main buildings—ADMIN, ENGINEERING, BUSINESS and MEDIA.

You, as a network expert, have to suggest the best network-related solutions for their problems raised in (a) to (d), keeping in mind the distances between the buildings and other given parameters.

Shortest distance between various buildings:

Number of Computers installed at various buildings:

(a) Suggest the most appropriate location for the server inside the Chennai campus (out of the 4 buildings) to get the best connectivity for maximum number of computers. Justify your answer.

(b) Suggest and draw the cable layout to efficiently connect various buildings within the Chennai campus for connecting the computers.

(c) Which hardware device will you suggest to be procured by the company to be installed to protect and control the internet use within the campus?

(d) Which of the following will you suggest to establish online face-to-face communication between the people in the Admin Office of the Chennai campus and Delhi Head Office?

(i) Cable TV

(ii) Email

(iii) Video conferencing

(iv) Text Chat

Answer

(a) The most suitable location for the server is the Admin Building because it has the highest number of computers (110). Placing the server here ensures maximum connectivity and data access for the maximum number of users.

(b) A star topology can be used to connect the Admin building directly to other buildings. This layout optimizes connectivity and data transfer efficiency within the Chennai campus. The cable layout is shown below:

(c) A Firewall/Router is recommended for network security and controlling internet usage within the campus. It filters network traffic based on security rules, protecting against unauthorized access and threats.

(d) Video conferencing

Reason — Video conferencing is the best option for online face-to-face communication. It provides real-time audio and video capabilities, facilitating effective collaboration between Chennai and Delhi offices.

Great Studies University is setting up its academic schools at Sunder Nagar and planning to set up a network. The university has 3 academic schools and one administration centre as shown in the diagram below:

Centre-to-centre distance between various buildings:

Number of computers in each of the Schools/Centre:

(a) Suggest the most suitable place (i.e., schools/centre) to install the server of this university with a suitable reason.

(b) Suggest an ideal topology for connecting these schools/centre.

(c) Which device will you suggest to be placed/installed in each of these schools/centre to efficiently connect all the computers within these schools/centre?

(d) The university is planning to connect its admission office in the closest big city, which is more than 350 km from the university. Which type of network out of LAN, MAN or WAN will be formed? Justify your answer.

Answer

(a) The most suitable place to install server of the university is Admin center because it has the maximum number of computers. This will help to keep maximum percentage of the network traffic local.

(b) A star topology is ideal for connecting the schools and centre.

(c) A Switch should be installed in each school/centre to efficiently connect all computers. Switches provide high-speed connections and efficient data transmission within local networks.

(d) A Wide Area Network (WAN) will be formed to connect the university's admission office in the closest big city, which is over 350 km away. WANs cover large geographic areas, such as different cities or countries.

Tech Up Corporation (TUC) is a professional consultancy company. The company is planning to set up new offices in India with its hub at Hyderabad. As a network adviser, you have to understand their requirements and suggest to them the best available solutions.

Block-to-block distance:

Expected number of computers to be installed in each block:

(a) What will be the most appropriate block where TUC should plan to install their server?

(b) Draw a block-to-block cable layout to connect all the buildings in the most appropriate manner for efficient communication.

(c) What will be the best possible connectivity out of the following to connect the new office in Bengaluru with its London office?

(i) Infrared

(ii) Satellite Link

(iii) Ethernet Cable

(d) Which of the following devices will you suggest to connect each computer in each of the above buildings?

(i) Gateway

(ii) Switch

(iii) Modem

(e) Write names of any two popular Open Source Software which are used as Operating Systems.

Answer

(a) Human Resource will be the most appropriate block where TUC should plan to install the server due to maximum number of computers (125).

(b) Block-to-block cable layout to connect all the buildings is shown below:

(c) Satellite Link

Reason — A Satellite Link would be the best option to connect the new office in Bengaluru with its London office. Satellite links offer reliable and high-speed communication over long distances, making them ideal for connecting offices in different locations.

(d) Switch

Reason — A Switch is recommended to connect each computer in each building. Switches allow multiple devices to connect and communicate within a local network.

(e) Two popular Open Source Software Operating Systems are Linux and Open Solaris.

Sony has set up its branch at Srinagar for its office and web-based activities. It has four Zones of buildings as shown in the diagram:

Branch-to-branch distance is:

Number of Computers:

(a) Suggest the most suitable cable layout or network topology of connections between the zones.

(b) Suggest the most suitable place (i.e., Zone) to house the ERP and BI Server of this organization with a suitable reason, with justification.

(c) Suggest the placement of the following devices with justification:

1. Repeater
2. Hub/Switch

(d) Which is the most economic type of cable for the selected topology ?

Answer

(a) The most suitable cable layout or network topology for connecting the zones is a bus topology.

(b) The most suitable place (i.e., Zone) to house the ERP and BI Server is Zone Z as it has the maximum number of computers which will reduce cabling cost.

(c)

(i) As per the suggested layout, separate repeaters need not to be installed as distance among zones is not exceeding 70m.

(ii) Hub/Switch should be placed in each zone.

(d) An economic type of cable is Ethernet or Coaxial cable as it can connect two computers at an economic rate though it provides lesser speed than other expensive methods.

Bhartiya Connectivity Association is planning to set up its offices in four major cities in India to provide regional IT infrastructure support in the field of Education & Culture. The company plans to set up their head office in New Delhi at three locations, naming them as "Front Office", "Back Office" and "Work Office". The company has planned three more regional offices—"South Office", "East Office" and "West Office" —in other major cities of India.

A rough layout of the same is as follows:

Approximate distance 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:

(a) Suggest network type (out of LAN, MAN, WAN) for connecting each of the following sets of their offices:

(i) Back Office and Work Office

(ii) Back Office and South Office

(b) Which device out of the following will you suggest to be procured by the company for connecting all the computers within each of their offices?

(i) Switch/Hub

(ii) Modem

(iii) Telephone

(c) Which of the following communication mediums will you suggest to be procured by the company for connecting their local office units in New Delhi for very effective and fast communication?

(i) Telephone Cable

(ii) Optical Fibre

(iii) Ethernet Cable

(d) Suggest a cable/wiring layout for connecting the company's local office located in New Delhi. Also, suggest an effective method/technology for connecting the company's regional office— "East Office", "West Office" and "South Office" —with offices located in New Delhi.

Answer

(a)

(i) For connecting the Back Office and Work Office, a LAN (Local Area Network) would be suitable as they are 70m apart.

(ii) For connecting the Back Office and South Office, a WAN (Wide Area Network) is required due to the long distance (1952 km).

(b) Switch/Hub

Reason — A switch or hub is essential for connecting all computers within each office as they facilitate communication between devices on the same network. They manage network traffic efficiently, ensuring smooth data transfer and communication.

(c) Optical fiber

Reason — Optical fibre is recommended for very effective and fast communication in New Delhi's local office units. It offers high-speed data transmission, reliability, making it ideal for modern network infrastructures.

(d) The cable/wiring layout is shown in the diagram below:

An effective method for connecting the company's regional office is Satellite.

Quick Learn University is setting up its academic blocks at Prayag Nagar and planning a network. The university has 3 academic blocks and one human resource centre as shown in the diagram given below:

Centre-to-centre distance between various blocks is as follows:

Number of computers in each of the buildings is as follows:

(a) Suggest a cable layout of connection between the blocks.

(b) Suggest the most suitable place to house the server of the organization with suitable reason.

(c) Which device should be placed/installed in each of these blocks to efficiently connect all the computers within these blocks?

(d) The university is planning to link its sales counters situated in various parts of the same city. Which type of network out of LAN, MAN or WAN will be formed?

Answer

(a) Cable layout of connection between the blocks is shown below:

(b) The most suitable place to house the server would be the HR Centre because it has the highest number of computers (115).

(c) A Switch/Hub should be placed in each block to efficiently connect all computers.

(d) A MAN (Metropolitan Area Network) will be formed to link the sales counters situated in various parts of the same city.

Prime Computer Services Ltd. is an international educational organization. It is planning to set up its India campus at Mumbai with its head office in Delhi. The Mumbai office campus has four main buildings — ADMIN, ACCOUNTS, EXAMINATION and RESULT.

You as a network expert have to suggest the best network-related solutions for their problems raised in (i) to (v), keeping in mind the distances between the buildings and other given parameters.

Shortest distances between various buildings:

Number of computers installed at various buildings:

(a) Suggest the most appropriate location of the server inside the Mumbai campus (out of the four buildings) to get the best connectivity for maximum number of computers. Justify your answer.

(b) Suggest and draw cable layout to efficiently connect various buildings within the Mumbai campus for a wired connectivity.

(c) Which networking device will you suggest to be procured by the company to interconnect all the computers of various buildings of the Mumbai campus?

(d) The company is planning to get its website designed which will allow students to see their results after registering themselves on its server. Out of the static or dynamic, which type of website will you suggest?

(e) Which of the following will you suggest for online face-to-face communication between the people in the ADMIN office of Mumbai campus and Delhi Head Office?

(i) Cable TV

(ii) Email

(iii) Video conferencing

(iv) Text chat

Answer

(a) The most appropriate location for the server would be the ADMIN building because it has the highest number of computers (110).

(b) A star topology can be used to efficiently connect various buildings within the Mumbai campus. Cable layout is shown in the diagram below:

(c) A Switch/Hub is recommended to interconnect all the computers of various buildings within the Mumbai campus.

(d) A dynamic website will be more suitable for the company's purpose. Dynamic websites can be updated regularly and interact with databases, allowing students to access personalized information such as their results after registering.

(e) Video conferencing

Reason — Video conferencing would be the most suitable option for online face-to-face communication between the ADMIN office of the Mumbai campus and Delhi Head Office. It offers real-time audio and video capabilities, enhancing collaboration and communication effectiveness.

What is internet?

Answer

The Internet is a world-wide network of computer networks. It connects many smaller networks together and allows all the computers to exchange information with each other.

What is network?

Answer

A network is a collection of interconnected computers and other devices to share data and other resources (hardware and software resources).

What are the various types of topologies?

Answer

The various types of topologies are as follows:

1. Bus or Linear topology
2. Ring or Circular topology
3. Star topology
4. Tree topology
5. Mesh topology

Describe bus topology and star topology.

Answer

1. Bus Topology — Bus topology is a multi-point configuration, i.e., several devices are connected to a main long cable (usually co-axial cable) which acts as a backbone. Nodes are connected by drop lines and taps. A drop line is a connection between long cable and devices and taps are the connectors that are punctured inside the main cable. The data flows from one end of the cable to the other. The cable has terminators at both ends which absorb signals when the signal reaches the end, preventing signal bounce. However, as the signal travels a long distance, it becomes weaker and weaker. It works well for small networks.

2. Star Topology — In star topology, each communicating device is connected to a central controller called a hub or switch. The devices in star topology send and receive data indirectly, the data passes to and from the hub. The central node can be either a broadcasting device (hub) or a unicast device (switch).

Define the following terms:

(a) Baud

(b) Communication channel

(c) Hubs

(d) Repeaters

Answer

(a) Baud — Baud refers to the number of discrete signal elements transmitted per second. It is the measuring unit of the data transfer rate.

(b) Communication channel — Communication channel is also known as transmission media through which data or signal is transferred between two communicating devices, i.e., from one system to another system, through wires or without wires.

(c) Hub — A hub is a networking device having multiple ports that are used for connecting multiple computers or segments of a LAN together.

(d) Repeater — A repeater is a device that amplifies a signal transmitted across the network so that the signal is received in the same way it is sent.

What is modem? Define the functioning of internal modem and external modem.

Answer

A MODEM (Modulator Demodulator) is an electronic device that enables a computer to transmit data over telephone lines. It is a device used to convert digital signals into analog signals and vice versa.

The functioning of internal modem and external modem is as follows:

1. Internal modem — These are attached to the internal slot of the motherboard. They modulate digital data into analog signals for transmission and demodulate incoming analog signals into digital data.

2. External modem — It is a small box connected to the communication port of the computer. It works similarly to the internal modem. The only difference is that it is placed outside the CPU box.

Expand and explain the following terms:

(a) PPP

(b) POP3

(c) VoIP

(d) IRC

Answer

(a) PPP — Point-to-Point Protocol (PPP) is one of the most commonly used data link protocols. It is utilized to establish a direct connection between two nodes and can provide various functionalities such as connection authentication, transmission, encryption, and compression. Communication occurs through a high-speed modem, and PPP is used to connect telephone dial-up lines to the internet.

(b) POP3 — Post Office Protocol version 3 (POP3) is a simple and standard method for accessing mailboxes and downloading messages to local computers. Users can receive messages using the POP3 protocol. An advantage of POP3 is that once messages are downloaded, an internet connection is no longer necessary to read the mail, as they are saved on the computer's hard disk.

(c) VoIP — Voice over Internet Protocol (VoIP) is utilized for transmitting voice communications. Voice calls undergo digitization, compression, and fragmentation into small packets, which are then transmitted across Internet Protocol (IP) networks. VoIP implementation allows users to carry voice traffic efficiently over an IP network.

(d) IRC — Internet Relay Chat (IRC) is an application layer protocol that enables users to share text messages. The sender sends a request to an IRC server, which then forwards the request to another client, facilitating communication between users.

Describe the following networking devices:

(a) Hubs

(b) Repeaters

(c) Routers

(d) Bridges

(e) Gateways

Answer

(a) Hubs — Hub is a multi-port and unintelligent network device which simply transfers data from one port of the network to another. It is used to connect several computers together with different ports. When the data packet reaches one port, it is copied to all other ports of the hub without changing the destination address. They can both send as well as receive information but only one task at a time. Hubs can be either active or passive.

(b) Repeaters — A repeater is a device that amplifies a signal transmitted across the network so that the signal is received in the same way as it is sent. It operates only at the physical layer of the OSI model. A repeater is a two-port network device that strengthens the signal intensity and connects two identical networks. A repeater does not change the functionality of the network; instead, it strengthens the signal before it degrades.

(c) Routers — A router is a networking device that forwards data packets from the source machine to the destination machine over a network using the shortest path available. It can handle different protocols. Routers utilize IP addresses to connect local area networks to the Internet. In contrast to a hub or a switch, a router possesses advanced capabilities as it can analyze the data being transmitted over a network, make decisions on how it is packaged, and route it to different computer networks.

(d) Bridges — A bridge is a device that operates at both the physical layer and the data link layer of the OSI model. It connects multiple network segments (LANs) at the data link layer (Layer 2) of the OSI model. It is a smarter hub as it can filter network traffic on the basis of the MAC addresses.

(e) Gateways — A gateway is a network device that connects dissimilar networks. It provides the necessary translation of data received from one network into a format or protocol recognized by devices within another network. A gateway establishes an intelligent connection between a local area network and external networks with completely different structures.

Name the device for the following:

(a) It stands for Modulator Demodulator.

(b) It regenerates the signals.

Answer

(a) Modem

(b) Repeater

Differentiate between MAN and WAN.

Answer

Differentiate between Website and Web page.

Answer

Differentiate between Router and Gateway.

Answer

Differentiate between Bus and Star topology.

Answer

Differentiate between Static and Dynamic web pages.

Answer

Identify the type of topology from the following:

(a) Each node is connected with the help of a single cable.

(b) Each node is connected with central switching through independent cables.

Answer

(a) Bus Topology

(b) Star Topology

Ravi, a Class X student, has just started understanding the basics of internet and web technologies. He is a bit confused between the terms 'World Wide Web' and 'Internet'. Help him understand both the terms giving suitable examples of each.

Answer

The World Wide Web (WWW) is a set of protocols that allows us to access any document on the Net through a naming system based on URLs. The WWW also specifies a way, known as the Hypertext Transfer Protocol (HTTP), to request and send hypermedia documents over the Internet.

The Internet is a worldwide network of computer networks that allows all computers to exchange information with each other. They follow protocols like TCP/IP (Transmission Control Protocol/Internet Protocol) for communication.

The WWW is a small part of the Internet. We can say that the Internet is a highway that offers many services and features, and the WWW is a vehicle (like a truck) that uses this highway to transport information.

Mani wants to send a report on his trip to the North-East to his mentor. The report contains images and videos. How can he accomplish his task through the internet?

Answer

Mani can send his trip report with images and videos to his mentor through email by attaching files or using chat platforms like WhatsApp or Facebook Messenger, as these platforms support the sharing of image and video files.

Ram is planning to open a company that deals with rural handicrafts. He wants to advertise about handicrafts on a social platform. Which internet service should he use and why?

Answer

Ram should use social networking platforms like Instagram and Facebook to advertise his handicrafts because they offer targeted advertising options that can reach a broad and diverse audience. Facebook provides a marketplace where he can sell his products directly and its cost effective.

What are Wi-Fi cards? Explain.

Answer

A WiFi card is either an internal or external Local Area Network adapter with a built-in wireless radio and antenna. It is used in a desktop computer to enable a user to establish an Internet connection. WiFi cards are known as wireless fidelity cards because they allow users to set up connections without any wires.

What is https? How does it work?

Answer

HTTPS stands for Hypertext Transfer Protocol Secure. It's a protocol that secures communication between two systems, like a browser and a web server, by encrypting data during transmission. When a user accesses a website using HTTPS, a secure connection is established, verifying the server's identity with digital certificates. This encryption and authentication ensure data privacy and integrity, crucial for protecting sensitive information such as passwords and financial data from interception or tampering by malicious entities on the Internet.

What are hubs? How are active hubs different from passive hubs?

Answer

A hub is a multi-port and unintelligent network device that simply transfers data from one port of the network to another. It is a hardware device used to connect several computers together using different ports.

Active hubs electrically amplify the signal as it passes from one connected device to another. They are often used like repeaters to extend the length of a network. In contrast, passive hubs allow the signal to pass from one computer to another without any alteration or amplification.

What are the facilities provided by the Server in a network environment?

Answer

Some services provided by a server on a network are:

1. Equipment/Resource Sharing — High quality printers and photocopiers are often designed to connect directly to a network and all authorised users can share the equipment. A server is responsible for such a resource sharing request.
2. Centralised File Saving for Data Sharing — Servers help the user save files to their home directories on the file server, workers can load their documents on any networked computer.
3. Centralised Virus Scanning — Most file servers run virus scanners constantly to detect and take care of viruses introduced by any user on any computer.
4. Centralised Backups — High-capacity tape devices in the file server back up all users' work, usually every night. In case of system failure (or worker failure), lost work can be recovered quickly and easily.

Which network is easy to expand?

Answer

Mesh network topology is easy to expand.

Which device filters the data and which device can handle different protocols?

Answer

Switch filters the data and router handles different protocol.

What is a network? What are its goals and applications?

Answer

A network is an interconnected collection of autonomous computers that can share and exchange information and resources.

Major goals and applications of networks are :

1. Resource Sharing — Through a network, data, software and hardware resources can be shared irrespective of the physical location of the resources and the user.
2. Reliability — A file can have its copies on two or more computers of the network, so if one of them is unavailable, the other copies could be used. That makes a network more reliable.
3. Reduced Costs — Since resources can be shared, it greatly reduces the costs.
4. Fast communication — With networks, it is possible to exchange information at very fast speeds.

What is the role of a switch in a network?

Answer

A switch is a device that is used to segment networks into different sub-networks, called subnets or LAN segments to prevent traffic overloading.

A switch is responsible for filtering i.e., transforming data in a specific way and for forwarding packets between LAN segments. To insulate the transmission from the other ports, the switch establishes a temporary connection between source and destination and then terminates the connection once the conversation is done.

Briefly discuss the role of a repeater in networking.

Answer

A repeater is a network device that amplifies and restores signals for long-distance transmission. It is used in long network lines, which exceed the maximum rated distance for a single run. Over distance, the cables connecting a network lose the signal transmitted. Repeaters are installed along the way in the network to ensure that data packets reach their destination without any degradation of the message.

Briefly discuss the role of a router in networking.

Answer

A router is a network device that forwards data from one network to another. A router works like a bridge but can handle different protocols. Based on a network road map called a routing table, routers can help ensure that packets are travelling the most efficient paths to their destinations. If a link between two routers fails, the sending router can determine an alternate route to keep traffic moving.

Briefly discuss the role of a bridge in networking.

Answer

A bridge is a device that links two networks together. Bridges are smart enough to know which computers are on which side of the bridge, so they only allow those messages that need to get to the other side to cross the bridge. Bridges can handle networks that follow same protocols.

Briefly discuss the role of gateway in networking.

Answer

A gateway is a network device that connects dissimilar networks. It establishes an intelligent connection between a local network and external networks with completely different structures.

In enterprises, the gateway is the computer that routes the traffic from a workstation to the outside network that is serving the Web pages. In homes, the gateway is the ISP that connects the user to the Internet.

When Rinku typed a URL in the address bar of her browser, Error 404 was displayed. Why did this happen? What can she do to avoid it?

Answer

Error 404 was displayed because the URL Rinku typed in the address bar of her browser is not valid or the webpage she is trying to access does not exist on the server. This can happen if the URL is misspelled, the webpage has been removed or renamed, or the server is down. To avoid this, Rinku can double-check the URL for any typos, try searching for the webpage using a search engine, or contact the website administrator to see if the webpage has been moved or removed.

When would you prefer hubs over repeaters.

Answer

Hubs are preferred over repeaters when the distance between the terminals of the network is less and signals are not lost during transmission.

When would you prefer bridges over hubs.

Answer

Bridges are preferred over hubs when we need to connect multiple networks.

When would you prefer switches over other networking devices.

Answer

We prefer switch over other network devices when we need to establish two-lane communication, facilitating send and receives at the same time. A switch provides full bandwidth to each connection and sends traffic only to appropriate connections, thus preventing traffic overload.

Shubham wants to play a video in his browser but is not able to do so. A message on the screen instructs him to install Adobe Flash Player plugin. Help him to add it in his browser.

Answer

Shubham can add the Adobe Flash Player plug-in to his browser by going to the Adobe Flash Player download page, clicking on the "Download Now" button, selecting the correct operating system and browser type, running the downloaded installer file, following the installation prompts, and restarting his browser after the installation is complete, which should then allow him to play the video in his browser.

Write the steps to install add-ons in google chrome web browser.

Answer

The steps to install add-ons in google chrome web browser are as follows:

1. Open Google Chrome.
2. Go to the Chrome Web Store.
3. Search for the add-on.
4. Click "Add to Chrome."
5. Confirm the installation.
6. Access and manage the add-on from the toolbar or extensions menu.

What are cookies? Why are cookies created?

Answer

Cookies are small text files stored on user's computer and created and used by websites.

Cookies are created by websites to remember basic information of the user and to record the user's browsing activity which helps in enhancing the user experience and making browsing time more productive.

What are the different components of email address?

Answer

Email address has two main parts — a username and domain name. The username comes before '@' and domain name comes after it.

For example, in abc@gmail.com, abc is the username and gmail.com is the domain name.

Identify the URL and domain name in the following:

www.cbse.nic.in/question_paper.html

Answer

The domain name is www.cbse.nic.in indicating the network domain hosting the website, while the URL is www.cbse.nic.in/question_paper.html, specifying the specific page or resource within that domain.