Network Technology — Unit 1: Introduction to Networks

5 Marks Question

Explain Types of Networks: Peer-to-Peer and Client/Server

Computer Network Architecture defines how computers are organized and how tasks and resources are allocated among them. There are two types of network architectures: Peer-to-Peer (P2P) and Client/Server.

1. Peer-to-Peer Network

A Peer-to-Peer network is a network in which all computers are connected with equal privileges and responsibilities for processing data. There is no dedicated server.

It is mainly suitable for small environments, usually up to 10 computers. Each computer manages and shares its own resources.

Advantages

Less Expensive

No dedicated server is required.

Reliable

If one computer fails, other computers can continue working.

Easy Setup

Easy to set up and maintain.

Disadvantages

No Centralized System

Taking a centralized backup is difficult.

Security Issues

Each device manages itself, which creates security issues.

Example: A small office where computers directly share files and printers with each other.

2. Client/Server Network

A Client/Server network consists of a central computer called the server and other computers called clients.

Clients access resources such as files, videos, directories and printers from the server. The server also performs important operations such as security and network management.

Advantages

Centralized Backup

Centralized system makes data backup easier.

Better Performance

Dedicated server improves overall performance.

Better Security

Resources are centrally managed.

Faster Sharing

Provides faster sharing of resources.

Disadvantages

More Expensive

A powerful dedicated server is required.

NOS Cost

Network Operating System (NOS) can be costly.

Administrator Required

Requires a dedicated network administrator.

Difference at a Glance

Peer-to-Peer	Client/Server
No dedicated server	Has a dedicated server
All computers have equal privileges	Server controls and manages clients
Suitable for small networks	Suitable for larger networks
Less expensive	More expensive
Less centralized security	Better centralized security

ConclusionA Peer-to-Peer network is simple and economical for small environments, while a Client/Server network provides centralized management, better security, and improved performance.

5 Marks Question

Explain Network Topologies

A Network Topology defines the structure of a network and describes how different nodes and components are interconnected.

There are two broad types of topology: Physical Topology and Logical Topology. The notes describe six physical network topologies: Bus, Ring, Star, Tree, Mesh, and Hybrid.

1. Bus Topology

All computers are connected to a single cable called the backbone cable. When a node sends data, the message is broadcast to all stations on the network.

2. Ring Topology

Each node is connected to another node, forming a continuous circular loop. Data normally flows in one direction, and token passing is used to transmit data.

3. Star Topology

Every node is individually connected to a central hub, switch, or computer. It is one of the most popular network topologies.

4. Tree Topology

Combines Bus and Star topology. Computers are arranged hierarchically, with the top-most node called the root node and other nodes acting as descendants.

5. Mesh Topology

Computers are interconnected through multiple redundant connections, providing multiple paths between computers. Full Mesh connects every computer to every other computer; Partial Mesh connects only selected computers directly.

6. Hybrid Topology

Formed by combining two or more different types of topologies, such as a Ring topology with a Bus topology.

Advantages and Disadvantages

Topology	Advantages	Disadvantages
Bus	Low installation cost; one node failure does not affect others.	Backbone failure disrupts communication; signal collision can occur.
Ring	Reliable; inexpensive twisted-pair cabling can be used.	One station failure can affect the network; more devices increase delay.
Star	Easy troubleshooting, expandable, individual cable failure is isolated.	Central hub/switch failure stops communication.
Tree	Easily expandable and manageable.	Can be costly; main bus failure can affect entire network.
Mesh	Highly reliable and fast communication.	Expensive and difficult to manage.
Hybrid	Reliable, scalable and flexible.	Complex design and high infrastructure cost.

In shortNetwork topology determines how devices are arranged and interconnected, and each topology has different advantages and disadvantages depending on the network requirements.

5 Marks Question

Explain Types of Networks: LAN, MAN and WAN

Computer networks can be categorized according to the geographical area or size they cover. The notes classify networks as LAN, PAN, MAN, and WAN; here, the question asks specifically for LAN, MAN, and WAN.

LAN — Local Area Network

A group of computers connected within a small geographical area, such as a building or office. It uses media such as twisted-pair or coaxial cable, is relatively low-cost, transfers data at very high speed, and provides higher security.

MAN — Metropolitan Area Network

Covers a larger geographical area than LAN by connecting multiple LANs together, such as different locations within a city. The notes list RS-232, Frame Relay, ATM, ISDN, OC-3 and ADSL.

WAN — Wide Area Network

Covers a very large geographical area, such as different states or countries. It can use telephone lines, fibre-optic cables, or satellite links. The Internet is one of the biggest WANs in the world.

Examples: LAN — college computer lab or office. MAN — banks within a city, airline reservation systems, a college across a city, military communication. WAN — 4G mobile broadband, telecom networks across cities, or a bank connecting multiple offices.

Difference Between LAN, MAN and WAN

Basis	LAN	MAN	WAN
Full Form	Local Area Network	Metropolitan Area Network	Wide Area Network
Coverage	Small area	Larger/city-level area	States or countries
Size	Smallest	Larger than LAN	Largest
Example	Office/building network	Banks across a city	Internet
Typical connection	Twisted pair/coaxial cable	Interconnected LANs	Telephone, fibre or satellite

In shortLAN covers a small local area, MAN connects networks over a larger metropolitan area, and WAN extends across very large geographical areas such as states and countries.

5 Marks Question

Explain Network Terminologies: Internet and Intranet

1. Internet

The Internet is a worldwide system of interconnected computer networks, also called a “network of networks.” It connects billions of computers around the world and allows users to communicate and access information.

The Internet uses the standard TCP/IP protocol suite for communication between computers. It is established using technologies such as optical-fibre cables, wireless communication, and other networking technologies.

Global / Public Network

Connects computers and networks worldwide.

TCP/IP

Uses TCP/IP for communication.

Information & Communication

Allows users to access information, communicate with other users, and access the World Wide Web (WWW).

Examples: Browsing websites, sending emails, online shopping, social media, etc.

2. Intranet

An Intranet is a private network within an organization or enterprise. It is used to securely share company information and computing resources among employees.

An intranet improves communication within an organization by allowing employees to access important information, links, applications, forms, and company databases. It can also be used for group work and teleconferencing.

Private Network

Mainly used within an organization.

Authorized Access

Only authorized users/employees can access it.

Secure Resource Sharing

Used for securely sharing company resources and information.

Access Control

Access rights can be maintained using a database containing employee usernames.

Difference Between Internet and Intranet

Internet	Intranet
Worldwide/global network	Private organizational network
Accessible publicly	Accessible to authorized users
Connects billions of computers	Connects users within an organization
Worldwide communication and information sharing	Internal communication and resource sharing
Example: WWW	Example: Company's internal employee portal

In shortThe Internet is a global network available worldwide, whereas an Intranet is a private network designed for secure communication and resource sharing within an organization.

5 Marks Question

Explain Network Terminologies: Unicast, Broadcast and Multicast

Casting in computer networks means transmitting data (a stream of packets) over a network. The three types of casting are Unicast, Broadcast, and Multicast.

Unicast — One-to-One

Data is transferred from a single sender to a single receiver. Network switches can use the MAC address to forward packets toward the required destination. It becomes less efficient when the same data must reach many receivers.

Broadcast — One-to-All

Data is sent from a single source to all other devices in the network. In a limited broadcast, data is transmitted to all other hosts residing in the same network.

Multicast — One-to-Many / Specific Group

Data is sent from a single source to a specific group of hosts interested in receiving it. Unlike broadcast, only the selected group receives the data.

Representations

Unicast:
Sender A ──────────> Receiver B

Broadcast:
             ┌──> B
Sender A ────┼──> C
             └──> D

Multicast:
             ┌──> B ✓
Sender A ────┼──> C ✓
             └──> D ✗

Multicast examples from the notes: Internet video/audio streaming, audio teleconferencing, and sending an email to a particular group of people.

Difference at a Glance

Type	Communication	Data Sent To
Unicast	One-to-One	One specific receiver
Broadcast	One-to-All	All hosts in the network
Multicast	One-to-Many	A specific group of hosts

In shortUnicast sends data to one receiver, Broadcast sends it to all hosts, while Multicast sends it only to a selected group of hosts.