Computer Network Tutorial

History of Computer Networks

1836 - 1840: These are the initial years of communication where people start thinking that there could be a method for communicating with each other. But at that time telegraph is the only communication medium.

1858 - 1866: Communication through Cables was started in these years. Cables are established between towns and cities for communication. But communication through cables is used in limited places.

1875 - 1880: In these years, Alexander Graham Bell developed a telephone device. And these were considered the initial steps for computer networks.

1957: Russia launched the satellite named SPUTNIK. America started ADVANCED RESEARCH PROJECT AGENCY (ARPA), and the first satellite of this was launched within 18 months of its establishment.

1961: During this period, Leonard Kleinrock invented the earliest computer network, which was the idea of ARPANET.

1962: In this year ARPA start collaborating with universities and Foundations for developing the sector, which later became ARPANET

1962 - 1968: Donald Davies coined the term packet. During this period packet switching was developed. The data transmitted over the network is divided into packets and then sent.

1969 - 1974: Ray Tomlinson developed Electronic Mail(E-mail) for transmitting data over the ARPANET. And at this time first international connection was successfully established between the University of Landon and the Royal Radar Establishment. TCP and TELNET protocol was also developed in these years.

1977 - 1983: In these years, the TCP/IP protocol suite is established for ARPANET. During this period, Communication through Email also becomes popular.

1983 - 1989: Tim Berners Lee developed World Wide Web, and today WWW is the backbone of the internet. And in this period, Users of the network and hosts increased drastically.

1990 - 1993: Search Engine concepts were taken into the picture in these years. The first browser was also introduced, and By Jean Armour Polly, the term surfing the internet was also coined in these years.

1994 - 1997: The number of websites and hosts increased drastically in these years, and World Wide Web Consortium (W3C) was also founded in these years.

1998: In this year, a company with an enormous amount of data and information was founded named, GOOGLE. Firewalls and Information Security were also taken into the picture in these years.

1999 - 2003: In these years, many popular protocols of networking were introduced, such as WiFi. Wireless technology was also starting to expand in these years, and devices start connecting wirelessly.

Why Learn Computer Networking?

Learning computer networking offers several benefits. Here are some reasons why it is valuable to learn computer networking:

• Understanding the Internet: Computer networking forms the foundation of the Internet. By learning computer networking, you gain a comprehensive understanding of how the Internet works, including the protocols, devices, and technologies involved. This knowledge allows you to navigate the digital world more effectively.

• Career Opportunities: Computer networking skills are highly sought after in the job market. Organizations of all sizes and across various industries rely on computer networks to facilitate communication, data sharing, and resource management. By acquiring networking knowledge, you enhance your employability and open up a wide range of career opportunities in fields like network administration, network engineering, cybersecurity, and cloud computing.

• Efficient Network Management: Learning computer networking enables you to effectively manage and troubleshoot networks. You can set up, configure, and maintain networks, ensuring optimal performance, security, and reliability. This knowledge is particularly valuable for businesses, as it helps them avoid network outages, bottlenecks, and security vulnerabilities.

• Enhanced Problem-Solving Skills: Networking involves complex problem-solving. As you learn about network design, protocols, and troubleshooting techniques, you develop analytical and critical thinking skills. These skills can be applied not only to networking challenges but also to other domains, making you a more versatile problem solver.

• Collaboration and Communication: Networking involves working with others to establish connections and enable communication between devices and users. By learning computer networking, you develop skills in collaboration, teamwork, and effective communication, which are essential in today's interconnected world.

How do Computer Networks Work?

Communication links and nodes are the basic building block of any computer network. A network node may consist of Data Communication Equipment ( DCE) and Data Terminal Equipment ( DTE). DCE consists of devices like modem, hub, or switch. DTE consist of devices like printer and computers. A Link is a transmission media that connects two or more devices. The link may be wireless or may be physical.

• Message is data that is to be communicated between sender and receiver. The message may be plain text, number, image, etc.
• Sender is the device which wants to send the message.
• Receiver is the device which wants to receive the message sent by the sender.
• Transmission media is the path through which the message travel from sender to receiver.
• Protocols are the set of rules and regulations that govern communication. Protocols define how the data will be transmitted between sender and receiver.

Types of Computer Networks

Based on the size of the network computer network is classified into four types:

• LAN(Local Area Network)
• PAN(Personal Area Network)
• MAN(Metropolitan Area Network)
• WAN(Wide Area Network)

LAN(Local Area Network)

A local Area Network is a network of connected devices in a small area such as offices or buildings connected.LAN is also used for the connection of two or more personal computers using communication media such as coaxial cable and twisted pair cable.

PAN(Personal Area Network)

Personal Area Network is used for connection of personal use devices of a person which ranges within 10 meters.

MAN(Metropolitan Area Network)

A metropolitan area network connects different LANs to build a large network, and it covers a geographical area over a city, town, etc. MAN is used by government agencies to connect private industries and citizens. MAN is smaller than WAN, but it is larger than LAN.

WAN(Wide Area Network)

A Wide Area Network covers a large geographic area such as a state or country. WAN is not just limited to a single location, but it extends over a large geographic area, and it is quite larger than LAN.

Characteristics of a Computer Network

• Computer Network allows data and resource sharing among connected devices.
• Create and store files on a computer and allow other devices of the computer to access those files.
• Connect a printer, fax machine, or a scanner to connect to one computer of a network and allow other devices of the network to access those machines.
• Computer networks provide us with a quick and efficient way for data communication.
• It provides security by preventing unauthorized access to data.
• Computer Network provides scalability means it can grow based on the requirements and provide good performance after the growth.

Examples of Computer Networks

Now let us understand computer networks with examples:

• The devices connected in an office are an example of a computer network.
• The biggest example of a computer network is the Internet which connects millions of users globally.
• Personal computer connected to other personal computers or other devices in a home or a building is also an example of computer networks.
• Computers connected in a lab of a college is an example of a computer network.
• A network of the branches of the company that are at geographical locations.

Advantages of Computer Networks

• File sharing: A computer network allows connected devices to share data and information.
• Resource sharing: Different connected devices in a network can share resources such as printers, and scanners between them
• Communication: The network allows the user to transmit messages and data in real-time.
• Cost: Hardware Cost is reduced as the computer network allows resource sharing among the devices of the network.
• Security: It provides security by allowing the limited interaction of the user with the entire system. For example, a bank only allows the user to access their account through ATM without allowing access to the entire database of the banking system.

Disadvantages of Computer Networks

• Lack of robustness: If a central connecting server of a network fails, then the entire network will not work

• Lack of independence: In a computer network, every work is done by utilizing the networking device, so a person is more dependent on more amount of device work rather than applying their efforts to get their job done.

• Virus and Malware: If by chance one device of the network gets contaminated by any virus, then there is a possible infection can spread to other devices.

• Expensive: The cost of creating and maintaining the computer network

Audience

The audience for computer networks can vary depending on the specific context and level of expertise being addressed. Here are some key audiences for computer networks:

• Students: Computer networks are commonly taught in academic settings, ranging from high school to university level.

• IT Professionals: Professionals working in the field of information technology, particularly those involved in network administration, network engineering, system administration, cybersecurity, or cloud computing, are a significant audience.

• Network Administrators and Engineers: Network administrators and engineers responsible for managing and maintaining computer networks within organizations form a specific audience.

• Network Architects: Network architects are responsible for designing and planning complex computer networks.

• System Administrators: System administrators need to understand networking principles to configure network interfaces, set up network services, manage IP addressing, and troubleshoot network-related issues.

What are the Pre-requisites for Computer Network?

To start learning computer networking, having a basic understanding of certain foundational concepts and technologies can be helpful. Here are some common prerequisites for studying computer networks:

• Computer Literacy: It is essential to have basic computer literacy, including knowledge of operating systems (such as Windows, macOS, or Linux), file management, using web browsers, and general familiarity with computer hardware.

• Networking Basics: Familiarity with basic networking concepts is beneficial. This includes understanding IP addresses, subnetting, network protocols (such as TCP/IP), and the concept of local area networks (LANs) and wide area networks (WANs).

• Internet Knowledge: Having a general understanding of how the Internet works is valuable. Knowledge of concepts like DNS (Domain Name System), HTTP (Hypertext Transfer Protocol), and how data is transmitted over the Internet will provide a good foundation.

• Operating Systems: Basic knowledge of operating systems is helpful, particularly in terms of configuring network settings, managing network interfaces, and understanding how networking is integrated into the operating system.

• Protocols and Standards: While not strictly a prerequisite, having some awareness of network protocols and standards like TCP/IP, Ethernet, Wi-Fi, and DNS can be advantageous. It helps you understand how different devices communicate and exchange data within a network.

Career Opportunity of Learning Computer Network

A career in Computer networks can be found in every large and small business. Below are given some of the career opportunities roles of learning computer network

• Network Administrators
• Network Technician
• Network Engineer
• Network Analyst
• Information Systems Administrator
• Computer Network Support Specialist
• Information Systems Manager
• Network Technician
• Computer Networking Instructor
• Network Programmer