COMPUTER NETWORK TYPES

A computer network is a group of computers and other devices connected to one another. It enables computers to communicate with each other and share:

• Resources
• Data
• Information
• Applications

Computer networks can be classified according to their geographical size and coverage area.

Major Types of Computer Networks

1. PAN – Personal Area Network
2. LAN – Local Area Network
3. MAN – Metropolitan Area Network
4. WAN – Wide Area Network

LAN (LOCAL AREA NETWORK)

A Local Area Network (LAN) is a group of computers and devices connected within a small geographical area.

Examples

Building, Office, School, Laboratory, Small campus

LAN is used to connect two or more computers through communication media such as:

• Twisted-pair cable
• Coaxial cable
• Ethernet cable

Features of LAN

• Covers a small geographical area.
• Generally connects computers within a building or office.
• Uses relatively inexpensive hardware such as:
  • Hubs
  • Network adapters
  • Ethernet cables
• Data is transferred at a very high speed.
• It is generally less expensive to set up and maintain than larger networks.

ETHERNET

Ethernet is a widely used technology and standard for connecting computers and other devices in a Local Area Network (LAN).

Features

• Usually uses cables for communication.
• Commonly uses twisted-pair cables.
• Devices are connected through network equipment such as switches and routers.
• Ethernet is widely used in homes, offices, schools, and institutions.

Important Standard

IEEE 802.3 is associated with Ethernet.

PAN (PERSONAL AREA NETWORK)

A Personal Area Network (PAN) is a network arranged around an individual person.

It generally operates within a short range, usually around 10 metres (approximately 30 feet).

PAN is used to connect personal electronic devices such as:

• Laptop
• Mobile Phone
• Media Player
• Personal Computer
• Gaming Devices

Thomas Zimmerman was one of the early researchers associated with the development of the concept of the Personal Area Network.

Types of PAN

A. Wireless Personal Area Network (WPAN)

A wireless PAN is created using wireless technologies such as:

• Wi-Fi
• Bluetooth

It is generally a short-range network.

B. Wired Personal Area Network

A wired PAN is created using wired connections such as:

• USB

MAN (METROPOLITAN AREA NETWORK)

A Metropolitan Area Network (MAN) covers a larger geographical area than a LAN.

It is created by connecting several LANs together to form a larger network.

LAN ────────┐

│

LAN ─────── MAN ─────── LAN

│

LAN ────────┘

Features and Uses

• Covers a city or metropolitan area.
• Connects multiple LANs.
• Larger than a LAN but generally smaller than a WAN.
• Government agencies may use MANs to connect with citizens and different offices.
• Private industries may also use MANs to connect their offices and facilities.

WAN (WIDE AREA NETWORK)

A Wide Area Network (WAN) is a network that covers a large geographical area.

It may extend across:

• States
• Countries
• Continents

A WAN is much larger than a LAN and is not limited to a single location.

Communication Media Used

WANs may use:

• Telephone lines
• Fibre-optic cables
• Satellite links
• Other long-distance communication technologies

Features and Uses

• Covers a very large geographical area.
• Connects networks located in different cities, states, or countries.
• Used extensively in:
  • Business
  • Government
  • Education
• The Internet is one of the largest WANs in the world.

CITY A             CITY B             CITY C

┌────────┐         ┌────────┐         ┌────────┐

│  LAN   │─────────│  LAN   │─────────│  LAN   │

└────────┘         └────────┘         └────────┘

\______________ WAN ______________/

Memory Trick

P – L – M – W

Personal → Local → Metropolitan → Wide

The coverage area generally increases in this order:

PAN  →  LAN  →  MAN  →  WAN

Smallest              Largest

INTERNETWORK

An internetwork is formed when two or more computer networks, such as LANs or WANs, or different network segments are connected using networking devices.

The process of connecting different networks is called Internetworking.

An internetwork may connect:

• Public networks
• Private networks
• Commercial networks
• Industrial networks
• Government networks

Internetworking generally uses the Internet Protocol (IP).

The Open Systems Interconnection (OSI) Model is a reference model used to understand network communication and internetworking.

TYPES OF INTERNETWORKS

1. INTRANET

An Intranet is a private network based on Internet protocols such as:

• Transmission Control Protocol (TCP)
• Internet Protocol (IP)

It is used within an organisation and is generally accessible only to authorised users.

ORGANISATION

│

┌─────────┴─────────┐

│                   │

OFFICE A             OFFICE B

│                   │

└────── PRIVATE ────┘

INTRANET

2. EXTRANET

An Extranet is a communication network based on Internet protocols such as:

• Transmission Control Protocol (TCP)
• Internet Protocol (IP)

It allows authorised external users, such as business partners, suppliers, or customers, to access selected information or services of an organisation.

Practice MCQ

1. Which of the following is related to a computer network that connects many computers?
    (A) LAN
    (B) Scan
    (C) Read
    (D) Write

HD(MPSC)

2. A computer network in which some of the links between the nodes are carried by open connections or virtual circuits in some larger network, such as an Internet instead of physical wires is a
 (A) virtual private network
 (B) virtual public network
 (C) virtual private net
 (D) virtual public net

Investigator DH (Jan-2024)