Internetworking Basics

What is a Network?

A network is a group of two or more devices connected by some transmission media, i.e., cables.

The purpose of designing a network is to enable the sharing of files and information between multiple devices.

Types of Network

There are following types of Network –

  • Local Area Network (LAN)
  • Metropolitan Area Network (MAN)
  • Wide Area Network (WAN)
  • Storage Area Network (SAN)
  • Campus Area Network (CAN)
  • Personal Area Network (PAN)

Local Area Network (LAN)

It is a computer network that interconnects computers within a limited area such as a residence, school, or office building.

It can achieve a high data transfer rate at a low cost.

Metropolitan Area Network (MAN)

It is a computer network that interconnects computers within a city or limited geographical area.

MAN is larger than a LAN but smaller than a WAN.

Wide Area Network (WAN)

It is a computer network that covers a city, country, or even the entire world. The Internet is an example of a WAN.

Storage Area Network (SAN)

SAN is a high-speed network of storage elements. It establishes direct and indirect connections between multiple servers and storage devices.

Gmail and Yahoo are an example of a SAN.

Campus Area Network (CAN)

It is a computer network that interconnects a few local area networks within a university campus or corporate campus.

Personal Area Network (PAN)

It is a wireless telecommunications network for device-to-device connection within a short range.

Bluetooth, USB is an example of a PAN.

What is an Internetworking?

An internetworking is a collection of individual networks, connected by intermediate networking devices that function as a single large network.

Internetworking uses Internet Protocol.

The standard reference model for internetworking is Open Standard Interconnection (OSI)


It is a set of rules and conventions for communication between network devices.


Hyper Text Transfer Protocol (HTTP)

File Transfer Protocol (FTP)

Address Resolution Protocol (ARP)

Types of Internetworking

There are three types of internetworking –

  • Internet
  • Intranet
  • Extranet


The internet is an extensive network of computers across the world.

  • It is an example of a Wide Area Network (WAN).
  • It uses telephone lines and satellite lines to communicate.
  • It allows activities such as messaging, shopping, and teaching takes place online.
  • It allows data and resources to be shared.


Intranet provides similar services to the internet –

  • It is a private network.
  • It is generally limited to one organization, such as a company or school.
  • It is used to share company information and computing resources among employees.


The extranet is a part of an intranet that can access by authorized people using the internet.

  • It is a network that uses the internet to link the company's intranet to enhance the business-to-business relationship.
  • It allows clients, partners, and vendors to access a variety of information.
  • It is a combination of both the internet and intranet.

Difference between the Internet, Intranet, and extranet

   Parameter      Internet      Intranet       Extranet
   Access       Public     Private By agreement only
    Users       Public Organization       members Business partners
   Accessibility       Anyone Authorized people Authorized People
   Availability Publicly worldwide Only in one location Multiple locations
   Information        sharing Across the world Within an organization Only between business partners

Why do we need internetworking?

We need internetworking for following primary reasons–

  1. Data Sharing

It allows users to:

  • Exchange information from one PC to another
  • Use E-mail, Facebook, and other related platforms to communicate
  • Route data from a user to another user
  • Exchange folders
  1. Resource Sharing

It allows users to share peripheral devices such as –

  • Printer
  • Scanners
  • Fax
  • Hard Disks
  1. Connection Sharing

It enables users to share a connection, such as:

  • Bluetooth
  • Hotspot
  • Wi-Fi
  1. Access to a remote database

It is easy for a person to access any remote database. For example, a database of trains, online universities, hotels can be accessed as per the requirements.

The remote-control program can be used to troubleshoot problems or guide new users on how to perform a task.

Internetworking Challenges

  • Implementing an internetwork is a difficult task; many challenges must be faced, especially in the areas of connectivity, reliability, and flexibility.
  • File security has to be taken care of, especially if connected to WANs.
  • Loss of packets.
  • Different addressing schemes.
  • It is difficult to troubleshoot a large network.