Class 10 [Computer] Lesson:1 Computer Network and Communication

Lesson 1 Computer Network and Communication: Glossary

·     3G (Third Generation): The third generation of mobile network technology that introduced faster internet browsing, multimedia messaging, and video calls.

·     4G LTE (Fourth Generation Long Term Evolution): A mobile network technology much faster and more reliable than 3G, offering high-quality video streaming and low latency.

·     5G (Fifth Generation): The latest mobile network technology, providing super-fast internet access, supporting the Internet of Things (IoT), and operating with almost no delay.

·     Bandwidth: The maximum amount of data a network can carry in a given time, measured in bits per second (bps).

·     Bluetooth: A wireless technology used for sharing data and connecting devices over short distances without cables.

·     Bridge: A networking device used to interconnect two computer networks that use similar protocols.

·     Broadband: A high-speed internet connection that allows for the quick transmission and receipt of large amounts of data.

·     CAT6 (Category 6): A common network cable used for fast Ethernet connections, capable of supporting speeds up to 10 Gbps over short distances.

·     Client-Server Network: A network model where powerful computers (servers) provide services to other computers (clients) that access them to perform tasks.

·     Computer Network: A group of two or more computers and devices connected to share data, resources, and messages.

·     Data Packet: A small part of a message broken down to travel across a network and be reassembled at its destination.

·     Extranet: A private network that allows an organization to share information securely with selected external users like suppliers or partners.

·     Fiber-optic Cable: A high-speed communication cable made of glass or plastic that transmits data using light pulses.

·     Frequency: The measurement of how often data signals are sent over a communication channel in one second, typically measured in kHz, MHz, or GHz.

·     Full Duplex Mode: A communication mode where data flows in both directions simultaneously.

·     Guided Media: Communication paths that use physical wires or cables, such as twisted pair or fiber optics, to transfer data.

·     Half-Duplex Mode: A communication mode where data flows in both directions, but only in one direction at a time.

·     Hub: A simple networking device with multiple ports used to connect computers in a star topology.

·     Internet: A global network of computers and devices that communicate using the TCP/IP protocol.

·     Intranet: A private network used within an organization for employee communication and resource sharing.

·     IP Address: A unique address assigned to each device on a network, responsible for routing data to the correct destination.

·     LAN (Local Area Network): A network limited to a small area like a room, building, or school.

·     MAN (Metropolitan Area Network): A network covering a larger area such as a city or a valley.

·     Network Protocol: A set of rules followed for interconnection and communication between computers in a network.

·     Network Topology: The interconnected physical or logical pattern of network components.

·     PAN (Personal Area Network): A small network used for connecting personal devices close to an individual, typically within 10 meters.

·     Peer-to-Peer (P2P) Network: A network where all nodes have equal relationships and can share resources without a central administrator.

·     Repeater: A device that accepts weak signals, regenerates them, and sends them on to allow for long-distance data transfer.

·     RFID (Radio Frequency Identification): A wireless technology using radio waves to transfer data between tags and readers for tracking and identification.

·     RJ-45 (Registered Jack 45): A standardized interface used for connecting Ethernet cables to network devices.

·     Router: An intelligent networking device that joins multiple networks together and determines the best path for data transmission using IP addresses.

·     Satellite Communication: A method of sending information wirelessly across the world using artificial satellites in space.

·     Simplex Mode: A unidirectional communication mode where data transmission takes place in only one direction.

·     Switch: A device that joins multiple computers to share information and coordinates between a file server and connected computers faster than a hub.

·     Telecommunication: The process of sending and receiving information over long distances using electronic devices.

·     Throughput: The actual amount of data successfully sent or received over a network in a specific period of time.

·     Unguided Media: Wireless communication that transfers data through the air using radio waves or signals instead of physical wires.

·     WAN (Wide Area Network): The largest type of computer network, extended over a large geographical area, often the entire world.

·     Wi-Fi (Wireless Fidelity): A wireless technology that uses radio signals on 2.4 GHz and 5 GHz frequency bands to connect devices to the internet.

1. Write the full form of the following abbreviations:

ADSL: Asymmetric Digital Subscriber Line (The sources define DSL as Digital Subscriber Line).

WI-FI: Wireless Fidelity

KBPS: Kilobits per second

MAC: Media Access Control (The sources mention macOS as an operating system but do not define the MAC abbreviation).

PPS: Packets Per Second.

IOT: Internet of Things

WCDMA: Wideband Code Division Multiple Access.

WiMAX: Worldwide Interoperability for Microwave Access.

MIMO: Multiple-Input Multiple-Output.

ITU: International Telecommunication Union.

MHz: Megahertz

CAT-6: Category 6

OFC: Optical Fiber Cable

GPS: Global Positioning System

PAN: Personal Area Network

WAN: Wide Area Network

NIC: Network Interface Card.

RJ-45: Registered Jack 45

Modem: Modulator-Demodulator
HTTPS: Hypertext Transfer Protocol Secure

SMTP: Simple Mail Transfer Protocol

POP3: Post Office Protocol version 3.

TCP/IP: Transmission Control Protocol/Internet Protocol

UDP: User Datagram Protocol.

DHCP: Dynamic Host Configuration Protocol

IPv4: Internet Protocol version 4

Short answer type questions.

1.    What is communication? Which was the first telecommunication service in Nepal?

Communication is the process of transferring data and information between computers and other electronic devices. Nepal Telecom was the first telecommunication service in Nepal.

2.    Define the term broadband with examples.

Broadband is a high-speed Internet connection that allows us to send and receive a large amount of data quickly. Examples include DSL (Digital Subscriber Line), Cable, Fiber-optic, Satellite, and Wireless (like 4G or Wi-Fi).

3.    Write any two differences between 4G and 5G wireless communication.

4G	5G
It was introduced in 2009	It was introduced in 2019.
It provides Ultra broadband service.	It provides wireless world wide web.
It is slower that 5G.	It is faster than 4G.
It has comparatively high latency (delay time).	It has lower latency.

 

4.    Write the common characteristics of CAT 6 Cable.

·     It supports speeds up to 1 Gbps over 100 meters and can reach 10 Gbps over shorter distances.

·     It is better insulation and tightly twisted wires to reduce signal interference.

5.    How do Media Connectors differ from Media Converters?

Media connector differ form media converter in the following ways:

Media connector	Media converter
A Media Connector is a hardware device (like an RJ-45) used to attach a cable to a network device such as a router or switch.	A Media Converter is a device that connects different types of media (like copper and fiber optic) by converting electrical impulses to light signals and vice versa.
: Provides a secure mechanical and electrical/optical connection between cables or between a cable and equipment.	Translates signals between different transmission media (e.g., copper ↔ fiber, single-mode ↔ multi-mode fiber).
Examples: RJ45 connectors (Ethernet), SC/ST/LC connectors (fiber optics), BNC connectors (coaxial).	Examples: ·     Fiber-to-Ethernet converters (convert optical signals to electrical signals). ·     Single-mode to multi-mode fiber converters.

 

6.    What is frequency? In which unit is it measured?

Frequency is how often data signals are sent over a communication channel in one second. It is measured in kHz (kilohertz), MHz (megahertz), and GHz (gigahertz).

7.    Write the features of Personal Area Network (PAN).

·     It works within a small range, typically up to 10 meters.

·     It connects personal devices like smartphones, tablets, laptops, and wearables.

·     It is easy to set up and requires only basic configurations.

8.    Define IP address with its parts.

An IP address is a unique address assigned to each device on a network to route data correctly. An IPv4 address consists of four numbers separated by periods (e.g., 192.168.1.1), while an IPv6 address consists of eight groups of four hexadecimal digits separated by colons.

9.    Write the function of tracert and NS-lookup commands.

tracert (traceroute): Traces the path data takes from the local computer to a destination, showing the number of "hops".

nslookup: Finds the IP address associated with a specific domain name.

10.How is broadband different from dial-up connections?

Broadband is much faster than the old dial-up Internet and allows for the quick transmission of large amounts of data, such as high-quality video.

11.Define bandwidth. How is it measured?

Bandwidth is the maximum amount of data a network can carry in a given time. It is measured in bps, kbps, Mbps, and Gbps.

12.What is a data packet in networking?

A data packet is a small part of a message that has been broken down to travel across a network; it is put back together once it reaches its destination.

13.What is frequency in telecommunications?

Frequency refers to how often data signals are sent over a communication channel in one second, which determines how fast and clearly signals travel.

14.What is the function of a repeater?

A repeater accepts weak signals, regenerates (boosts) them, and sends them on to allow for long-distance data transfer.

15.What is a computer network? How is it useful?

A computer network is a group of two or more connected computers and devices. It is useful for sharing resources (like printers and hard disks), files, and messages, as well as accessing services like the Internet and e-banking.

16.Why is wireless communication becoming more popular today?

Wireless communication becoming more popular because it allows users to connect to the Internet and share files easily without physical cables, supporting the mobility of modern devices.

17.Describe the RJ45 connector. Where is it commonly used?

The RJ45 is a standardized interface with eight pins in a modular jack format. It is commonly used for connecting Ethernet cables to devices in Local Area Networks (LANs).

18.What is a media converter? Mention its main function.

A media converter is a network device that links different cable types. Its main function is to convert electrical impulses from copper cables into light signals for fiber optic lines (and vice versa).

19.What is the difference between bandwidth and throughput?

Bandwidth is the maximum (theoretical) capacity of a network, while throughput is the actual amount of data successfully sent or received in a certain time.

20.How does Wi-Fi transmit data without cables?

It uses radio signals on the 2.4 GHz and 5 GHz frequency bands to send and receive data through access points like routers.

21.How does data travel from one computer to another in a network?

Data is broken into packets that travel through a communication medium (wired or wireless) and are directed to the correct destination using IP addresses and protocols.

22.How does data flow in a ring topology?

In a ring topology, data is transferred sequentially in a closed loop where each computer is connected to another, with the last one linked back to the first.

23.Mention one real-life use of satellite communication.

Real-life uses include TV broadcasting, weather forecasting, military communication, GPS navigation, and Internet services.

24.List two types of communication media and give one example of each.

·     Guided Media: Example: Optical fiber cable or CAT6 cable.

·     Unguided Media: Example: Wi-Fi or Bluetooth.

Write long answer to the following questions.

1. What is communication media?  Differentiate between guided and unguided communication media with examples.

Communication media, also known as transmission media, is the physical or wireless path used to send data and information between devices in a network. It serves as the channel that connects various devices to enable the sharing of messages and data.

Differences between Guided and Unguided Media:

Guided Media (Wired)	Unguided Media (Wireless)
This media uses physical wires or cables to transfer data.	This media transfers data through the air using radio waves or signals instead of physical wires.
It provides a fixed path or direction for the signals to follow.	There is no fixed path, meaning data travels freely through the atmosphere.
It is generally faster, safer, and more reliable than wireless options because it is not affected by weather conditions like rain or wind.	It is highly useful for mobile services but can be affected by weather conditions.
Examples include CAT6 (Category 6) cables, Coaxial cables, and Optical fiber.	Examples include Wi-Fi, Bluetooth, RFID, and Satellite communication.

 

2. Define the term computer network with diagram.  Write the advantages and disadvantages of computer network.

A computer network is a group of two or more computers and devices connected through wired or wireless media to exchange data, information, and share resources.

Advantages of Computer Networks are:

a) Resource Sharing: Connected computers can share hardware devices like scanners, printers, and hard disks, etc.

b) Information Sharing: It allows for global communication and data exchange through the Internet.

c) Centralized Administration: Networks support the management of all connected systems from a central point.

d) Data Backup: Networking provides facilities for centralized data and software backup.

Disadvantages of Computer Networks:

a) Security Risks: Networks, especially the Internet, are generally less secure and require precautions like firewalls to prevent unauthorized access.

b) Complexity and Cost: Setting up complex networks can be expensive and requires technical knowledge to maintain.

c) Technical Failures: If critical devices like a router or a central switch fail, it can interrupt service for the entire segment.

3. What is Network Topology? Sketch and explain about the star topology with its merits and demerits.

Network topology is the physical or logical interconnected pattern of network components.

Star Topology: In a Star Topology, every node is connected to a central device (such as a hub or switch) through a dedicated cable. This is the most common type of network topology.

Merits of Star Topology:

High Performance: It provides fast data transfer and keeps network traffic low.

Easy Maintenance: It is easy to set up, modify, and troubleshoot.

Reliability: The failure of one node does not affect the rest of the network, making it very stable.

Demerits of Star Topology:

Central Point of Failure: If the central hub or switch fails, the entire network stops working.

Cable Cost: It requires more cabling compared to a bus topology, as every computer needs its own line to the center.

4. What is network architecture? Compare between client server and peer to peer architecture.

Network architecture is the way how computers communicate and interact, combining physical topologies with specific data transmission modes.

Comparison between Client-Server Architecture and Peer-to-peer (P2P) Architecture.

Client-Server Architecture	Peer-to-Peer (P2P) Architecture
A central powerful computer (Server) provides services to others (Clients).	All nodes have equal relationships; there is no central controller.
Requires a dedicated system administrator for central management.	Each user controls their own shared resources; no admin needed.
Better security because resources are centrally administered.	Security is lower as it is managed individually by users.
Centralized backup is possible, making data recovery easier.	Users must back up their own data individually.
High; dedicated servers increase the speed of sharing as the network grows.	Suitable only for small areas like small offices or homes.

 

5. What is TCP/IP model? Describe different layers of TCP/IP model With diagram.

The TCP/IP (Transmission Control Protocol/Internet Protocol) is a set of rules followed for interconnection and communication between computers on the Internet. It is the global standard that allows people to share information and communicate across long distances.

6. What is IPV 4 address? Describe different classes of IPV 4 addressing?

IPv4 (Internet Protocol version 4) is the most widely used version of IP today. It uses 32-bit addresses, which allows for approximately 4.3 billion unique addresses. These addresses are written in dotted-decimal notation, consisting of four numbers separated by periods (e.g., 192.168.1.1

The different classes of IPV4 addressing are:

Class A IP addresses are used for very large networks, such as multinational corporations or ISPs. The first octet of a Class A IP address ranges from 1 to 126, with a default subnet mask of 255.0.0.0. This class supports 126 networks and approximately 16.7 million hosts per network.

Class B addresses are suitable for medium-sized networks, like universities or large businesses. They use the first two octets for the network portion, with values ranging from 128 to 191 in the first octet. The default subnet mask for Class B is 255.255.0.0, supporting 16,382 networks and 65,534 hosts per network.

Class C addresses are common for small local area networks (LANs). The first three octets are used for the network ID, with the first octet ranging from 192 to 223. The default subnet mask is 255.255.255.0, allowing for over 2 million networks with up to 254 hosts each.

Class D is reserved for multicast groups, which are not tied to a specific network and do not have a traditional network/host split. Multicast IP addresses range from 224.0.0.0 to 239.255.255.255 and are used for streaming media and other group-oriented services.

Class E is reserved for experimental purposes and is not used in standard networking. Its range is from 240.0.0.0 to 255.255.255.255.

7. What is IPV 6?  Differentiate between IPV 4 and IPV 6 addressing.

IPv6 (Internet Protocol version 6) was developed to solve the address exhaustion problem of IPv4. It uses 128-bit addresses, providing a vastly larger address space (3.4 × 10³⁸).

Differences between IPv4 and IPv6:

IPv4	IPv6
It is 32 bit addressing in decimal format.	It is 128 bit addressing in hexadecimal format.
It consists of 4 fields and 8 bits (octets) separate by dots(.). (e.g., 192.168.1.1).	It consists of 8 fields and 16 bits separated by colon (:).
It can generate approximately 4 billion unique addresses.	It can generate 3.4X1038 unique address.
Encryption/Authentication not built-in.	Includes built-in security features.

8. What is DHCP? Explain the application of DHCP.

DHCP (Dynamic Host Configuration Protocol) is a system that automatically assigns IP addresses to devices on a network.

Applications of DHCP:

·     It allows devices to connect to the Internet immediately without manual setup.

·     It manages a pool of IP addresses and assigns them as devices join or leave the network, preventing conflicts.

·     Network administrators do not have to manually configure each computer, which is essential in large networks.

9. Suppose you are network administrator of a company. Which network topology do you choose in the company? Why?

As a network administrator, the best choice for my company would likely be the Star Topology or a Hybrid Topology. This is because Star Topology is preferred for individual departments because it is easy to troubleshoot and a single cable failure will not bring down the entire office. Hybrid Topology is ideal for the whole company as it allows the administrator to connect multiple star networks with a high-speed backbone and offers scalability as the company grows.

 

10. Compare optical fiber cable with Cat 6 cable in terms of attenuation and data transmission rate. Why optical fiber cables are more beneficial then Cat 6 cable?

Comparison of optical fiber cable with Cat 6 in terms of attenuation and data transmission rate are:

·     Attenuation (Signal Loss): Optical fiber has minimal loss because it uses light pulses. CAT6 uses electrical signals through copper, which are more prone to interference and loss over distance.

·     Data Transmission Rate: Optical fiber is significantly faster, capable of carrying terabytes of data over long distances at near light speed. CAT6 supports up to 1 Gbps over 100 meters and up to 10 Gbps over very short distances.

Optical fiber cables are more beneficial than CAT 6 cable because It is more powerful, reliable, and efficient. It can be bent without breaking despite being made of glass and is thinner than a human hair, making it the top choice for ISPs and high-speed backbones.

11. Why do most of the financial institution like bank choose client server architecture rather than P2P? Give suitable reasons.

Financial institutions like banks choose Client-Server architecture for the following reasons:

·     Better Security: All shared resources are centrally administered, which is vital for protecting sensitive financial data.

·     Centralized Backup: Banks need to ensure data is never lost; this architecture allows for system-wide backups on the server.

·     High Performance: Dedicated servers increase the speed and reliability of resource sharing, which is necessary for processing high volumes of transactions.

12. Which communication channel (Optical fiber or Cat 6 ) Is best suited for a school networks? Describe with appropriate logic.

CAT 6 is best suited for a school networks because of the following reasons.

·     CAT6 provides up to 1 Gbps, which is more than enough for student research and classroom activities.

·     It is standard for Local Area Networks and is easier to install/terminate than fiber.

·     It features tightly twisted wires and better insulation to reduce interference in a busy school environment.

13. Differentiate between LAN and MAN.

13. Differentiate between LAN and MAN

Local Area Network (LAN)	Metropolitan Area Network (MAN)
It is suitable for small area (room, building, school).	It is suitable for larger area (city, valley, metropolitan).
It has higher speed data transfer.	It has slower than LAN but faster than WAN.
Usually owned by a single organization.	Can be owned by single or multiple organizations.
Low transmission error rate.	Transmission error is higher than LAN.
Example: School computer lab.	Example: Cable TV networks or city-wide DSL.

14. Suppose your school wants to set up a network in three separate buildings. What type of network should be used? Justify your answer by explaining how it would support communication, file sharing, and internet access.

A school with three separate buildings. It should use a MAN (Metropolitan Area Network). The justification that it would support communication, file sharing and internet access are:

·     Communication: It provides uplinks to connect different LANs within a campus or city area.

·     File Sharing: It facilitates the sharing of different resources across different locations.

·     Internet Access: A MAN can provide a central high-speed connection point that serves all three buildings simultaneously.

 

15. Create a network model for your home that includes three PCs, one printer, and one mobile device connected to the internet. Describe the devices, connection types (wired or wireless), and technologies (router, switch or Wi-Fi) you would use.

Hardware & Device Descriptions

• Modem/Router Combo: The central gateway connecting your home network to the Internet Service Provider (ISP). It assigns local IP addresses using DHCP and handles network traffic routing.
• 5-Port Gigabit Switch: A hardware device that expands the number of available wired ports. It forwards data only to the specific device it is addressed to, keeping network speeds fast.
• Three PCs: General-purpose computers used for heavy data tasks, gaming, or work, requiring stable network performance.
• One Printer: A shared network printer equipped with an Ethernet port for universal access.
• One Mobile Device: A smartphone or tablet requiring untethered internet access throughout the house.

 

 

16. Which network type would be more suitable for a small office: client server or peer-to-peer? Justify your answer by comparing features like cost, security, scalability, and management.

For a small office, a Peer-to-Peer (P2P) network is usually more suitable. This is because:

·     Cost: P2P is much lower cost because it doesn't require an expensive server or specialized server software.

·     Management: It does not require a dedicated administrator, as each user can manage their own resources.

·     Scalability: While limited, it is perfectly adequate for a small group of users in a single room or building.

·     Security: Although lower than client-server, it is sufficient for basic needs where users trust one another.

 

17. Design a simple layout for a school computer lab network using at least one switch, 10 computers, and internet access. Explain your design choices and how the devices would communicate with each other

 

Our layout Choice is Star Topology. The components used and how it communicate are given below:

·     Central Device: One Switch will be placed in the center of the lab.

·     Connections: All 10 computers will be connected directly to the switch using CAT6 Ethernet cables with RJ-45 connectors.

·     Internet Access: The switch will be connected to a Router or Modem, which links the lab to the ISP.

·     Communication Logic: When one computer sends data, the switch (an intelligent device) determines the correct path using IP addresses to ensure it reaches only the intended recipient, making communication fast and efficient.