Unit 2: Networking And Internet

Understand Computer Networking

Introduction – Networking

Computer networks have extended the power of a computer beyond the expanse of a room. It has transformed the world into a global village.

A networking is a collection of computers (or computer like devices) that are able to communicate with each other through some medium or device, using hardware and software. Two or more computers are said to be connected, if they are able to exchange information or communicate.

The computers in a network can communicate with each other as well as work independently. Each computer in a network is called a Node or Workstation The computers in a network can be linked through cables, telephone lines, radio waves, or infrared light beams.

Every network includes elements to enable data transfer or sharing are given below.

At least two computers or similar devices.

• Network interfaces
• A connection medium
• Operating system, strategies and algorithms

Advantages of Networking

Networking in computers brings efficiency, economy, and effectiveness in any organisation. Some of the advantages of networking are listed below:

• Resource Sharing: In a computer network, all the hardware and software resources are shared among the users of the network. The additional peripheral devices, such as printer, scanner, modems, fax machines, etc., can be connected to one central computer and shared among the others. Also, it becomes very easy and convenient to share the data and files among the users of a computer network. It saves the time that is spent in transferring a file from one machine to another using a storage device.
• Reduction in Cost: The cost of hardware is considerably less in a computer network as all the computers share the hardware resources. The software cost can also be saved by purchasing the software and licences for the server, and distributing them to the clients.
• Increased Storage Capacity: As in a network, the users can store their files on remote computers, so they get more space to store their data.
• Fast Data Transfer: Networking provides a facility to transfer the soft copies from one computer to the other at a high speed.
• Easy to Take Backup: It is difficult to maintain regular backups on a number of stand-alone computers. You can set the server in a network to take regular backup of data automatically.
• Reduces Data Inconsistency: When multiple mismatching copies of a file are stored at different computers, it is called data inconsistency. In a network, the deletion, modification, or updation of the files can be done at a single point only. This reduces data inconsistency and brings in more efficiency.
• Reduces Data Redundancy: Data redundancy means duplication of data at multiple places. A computer network helps in reducing the data redundancy by providing a central server to store the data. The client computers can access the data whenever required by sending a request to the server.
• Increases Security: In a computer network, the users are assigned ids’ and passwords for authentication to access the data and files. Only the authorised users are allowed to access the hardware and software resources. It is the duty of the network administrators to adopt preventive measures to protect the networks from potential security threats.

Disadvantages of Networking

There are few disadvantages of computer networks. Some of them are as follows:

• Additional Cost of Networking Equipment: A network’s cost might get reduced by sharing the hardware resources. However, additional cost of establishing the network gets incurred.
• Management of Large Network: Managing a large computer network can be a challenging task. It requires expertise and special training.
• Server Breakdown: If the server breaks down in a network, then all the computers become isolated.
• Security Issues: A computer network is always at the risk of getting attacked by external threats, such as unauthorised use of resources, virus attacks, and alike. If the network is not secured, then the data of the organisation may be at a high risk.

Need and Benefits of Networking

Components of a network: sender, receive, message, channel, Transmission Medium (wired and
wireless)

Telephone Network standard (technology used in each generation)

Working Devices / Networking Components

RJ45 connector

Modem

Repeater

Hub

Switch

Bridge

Gateway

Routers

Network Topology (Bus, Star, Ring, Tree, Mesh)

Types of Networking

The types of networks based on their coverage areas are as given below

Personal Area Network (PAN)

PAN is a computer network that is mainly created for an individual person. It is also known as Home Area Network (HAN). It is used for communication among devices, such as laptops, mobile phones, Personal Digital Assistants (PDAs), or smartphones. Personal area networks can either be wired or wireless. It generally covers a range of less than 10 metres (about 30 feet).

You can use these networks to transfer the files including mails, calendar appointments, digital photos, and music.

Local Area Network (LAN)

LAN is privately owned network within a single building or campus. It is also known as Campus Area Network (CAN). In Local Area Networks, two or more computers and peripheral devices are connected within a small area, such as a room, an office building, or campus.. Since it is operated in a small area, it can be controlled and administered by a single person or an organisation. The data transmission speed in LAN is very fast.

Metropolitan Area Network (MAN)

MAN is larger network than LAN and spread across a city. Since it covers an entire city, it is called metropolitan. The most common example of the MAN is the city cable network or branches of a local bank in a city.

Wide Area Network (WAN)

This kind of network connects two or more computers located at distant places. They are linked by communication facilities, like telecommunication or satellite signals. The main characteristic of WAN is that it requires a public telecommunication media to transfer data. The common examples of WAN is internet. It is also known as Network of Networks (i.e. internet)

Value-Added Network (VAN)

To understand Internet and its terminology

Introduction and use of Internet

Digital Literacy

Terminology (Channels, Bandwidth (HERTZ, KHZ), ISP)

Internet Devices: Repeater, Hub, Switch, Gateway, Bridge, Router

Data Transfer Rate (bps, Kbps, KBps, Mbps, MBPS, Gbps, GBPS)

Protocols (TCP/IP, FTP, HTTP, SMTP, POP3, PPP, UDP)

Understand cybercrime and the need of Cyber Security

Network safety concerns: (Digital Footprints, Threats, Virus, Worm, Trojan Horse, Spam, Malware, DoS Attacks, Eavesdropping, Adware, Spyware, Snooping)

Networking Security Measures (Antivirus, Firewall, Login ids and Password)

Cyber Crime (Phishing, Pharming, Spoofing, Cyber Bullying, Hacking, Cracking, Identity Theft, Cyber Stalking, Cyber Trolling,

Cyber Safety (Netiquettes, IT Act, Cyber Laws)