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Computer Networking ESSENTIALS

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Jalaj Bhatt
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INTRODUCTION

Computer networking has become an essential aspect of modern life, allowing individuals and organizations to communicate and share resources effectively. In this article, we will delve into the world of computer networking, exploring its types, topologies, protocols, OSI model and some other essential topics. So let's get started.

WHAT IS COMPUTER NETWORKING?

Computer networking is the process of connecting multiple computing devices, such as computers, servers, and other network devices, to share information, resources, and services through a system of interconnected hardware and communication protocols.

In simple words, multiple computers or devices connected to exchange resources is computer networking.

WHAT IS INTERNET?

Internet is a collection of various networks, or it is the network of all networks.

HOW DID IT START(HISTORY)

Somewhere around 1957, USSR launched the first artificial Earth satellite "SPUTNIK I", in response to this "ARPA" (stands for Advanced Research Project Agency) was launched by the United States Department of Defense.ARPANET was the first packet-switching network and laid the foundation for the modern internet. In the 1970s and 1980s, networking technologies such as Ethernet, TCP/IP, and the World Wide Web were developed, enabling global communication and information sharing.

WWW (World Wide Web)

The World Wide Web is an Information System where documents and other web resources are stored and are identified by "Uniform Resource Locators (URLs)" which may be interlinked by hyperlinks and are accessible over the internet.

Think of it like a project which stores documents and other resources over the internet and we can access these documents via WWW.

TYPES OF NETWORKS

A computer network is mainly of four types:

  • LAN(Local Area Network):

    It is built for small areas like buildings, offices etc.

  • PAN(Personal Area Network):

    This network is arranged within a person, typically within a range of 10 meters. It can be wired or wireless.

  • MAN(Metropolitan Area Network):

    A metropolitan area network is a network that covers a larger geographic area by interconnecting a different LAN to form a larger network.

  • WAN(Wide Area Network):

    A Wide Area Network is a network that extends over a large geographical area such as states or countries.

NETWORK TOPOLOGIES

Network topologies refer to the arrangement of various elements such as nodes, links, and devices within a computer network. There are several types of network topologies, including:

  1. Bus topology: All devices are connected to a single central cable, known as the bus or backbone.

  2. Ring topology: Devices are connected in a circular pattern, with data traveling in one direction around the ring.

  3. Star topology: All devices are connected to a central hub, which acts as a relay for data transmission.

  4. Mesh topology: Each device is connected to multiple other devices, providing multiple paths for data transmission and increased redundancy.

  5. Tree topology: A combination of star and bus topologies, with multiple star networks connected to a central bus.

  6. Hybrid topology: A combination of two or more different topologies, such as combining a star and ring topology.

NETWORK PROTOCOLS

Network protocols are rules that govern the communication and exchange of data over a network. They define the format, structure, and procedures for transmitting information between devices. Examples of network protocols include HTTP, FTP, TCP/IP, and SMTP.

Think of it like this, we send and receive different types of data over the internet (emails, videos, secure files etc) so different types of rules will be required, these rules are called Protocols. Now lets the study basics of some of these protocols

HTTP

HTTP (Hypertext Transfer Protocol) is a network protocol that allows the transfer of data, such as webpages, images, and other resources, over the internet between a client (web browser) and a server.

FTP

FTP (File Transfer Protocol) is a network protocol used to transfer files from one computer to another over the internet or a local network.

TCP/IP

TCP/IP (Transmission Control Protocol/Internet Protocol) is a set of communication protocols used for transmitting data over networks, particularly the Internet. TCP/IP is responsible for ensuring the reliable delivery of data packets and proper routing between devices on a network.

UDP

User Datagram Protocol (UDP) is a communication protocol used for transmitting data over networks without the need for a connection. It is faster and has lower overhead compared to TCP, but it does not guarantee reliable delivery of data packets.

SMTP

Simple Mail Transfer Protocol (SMTP) is a communication protocol used for sending email messages between servers and also from clients to servers for email delivery.

HTTPS

HTTPS (Hypertext Transfer Protocol Secure) is an encrypted version of HTTP, providing secure communication over a computer network by encrypting the data transmitted between the client and server. It uses SSL/TLS protocols to ensure the privacy and integrity of the data exchanged.

NOTE: Internet Society is responsible for creating the rules or protocols of file transfer and resource transfer over the Internet.

IP ADDRESS

An IP address (Internet Protocol address) is a unique numerical label assigned to each device connected to a computer network that uses the Internet Protocol for communication. It serves two main functions: identifying the host or network interface and providing the location of the host within the network. There are two versions of IP addresses: IPv4 and IPv6. IPv4 addresses consist of four sets of numbers separated by periods, while IPv6 addresses have eight sets of four hexadecimal digits separated by colons.

To check the IP address of your laptop, open the Command Prompt on Windows or Terminal on Linux and macOS. Type "ipconfig" for Windows or "ifconfig" for Linux and macOS, then press Enter. Your IP address will be displayed in the output.

PORTS

A port is a communication endpoint in a networking context, used by protocols like TCP and UDP to establish connections between devices. Each port is identified by a unique number, allowing multiple simultaneous connections between devices.

NOTE: IP address decides which device to send the data whereas ports help to decide which application to send the data.

OSI MODEL

The OSI model (Open Systems Interconnection model) is a conceptual framework that standardizes the functions of a telecommunication or computing system into seven abstract layers. These layers, from top to bottom, are Application, Presentation, Session, Transport, Network, Data Link, and Physical.

  1. Physical Layer: This layer deals with the physical connection between devices, such as cables, switches, and hubs. It is responsible for transmitting raw bits over the network.

  2. Data Link Layer: This layer is responsible for organizing raw bits into frames, error detection and correction, and flow control. It includes protocols like Ethernet and MAC addresses.

  3. Network Layer: The Network Layer is responsible for routing and forwarding data packets between different networks. It uses IP addresses and protocols like IP and ICMP.

  4. Transport Layer: This layer is responsible for ensuring reliable data transmission between devices, managing error recovery and flow control. It uses protocols like TCP and UDP.

  5. Session Layer: The Session Layer establishes, maintains, and terminates connections between applications on different devices. It also manages synchronization and data exchange during a session.

  6. Presentation Layer: This layer is responsible for translating data into a format that can be understood by both the sender and receiver. It deals with data encryption, compression, and character encoding.

  7. Application Layer: The Application Layer is the highest layer in the OSI model and provides the interface between the user and the network. It includes protocols like HTTP, FTP, and SMTP, which are used by applications to send and receive data.

STATUS CODES

Status codes are three-digit numbers that indicate the outcome of an HTTP request, providing information about the success, failure, or other conditions of the request. Common status codes include 200 OK, 404 Not Found, and 500 Internal Server Error.

COOKIES

Cookies are small pieces of data stored on a user's computer by a web browser while browsing a website, used to remember information about the user, such as login details and preferences, to improve the browsing experience and provide personalized content.

DNS

Domain Name System (DNS) is a system used to translate human-readable domain names, such as www.example.com, into IP addresses, such as 192.168.1.1, which computers use to identify each other on a network. This makes it easier for users to access websites and other resources on the internet without having to remember numerical IP addresses.

Think of it like this, when we type let's say google.com then the browser will use DNS to find the IP address of Google's server and then it will connect to the server.

DNS is a Directory/Database service having big databases. Now we know that there are many URLs, so if we had just one database then it won't be enough, hence databases are divided into various classes of domains as mentioned below:

A top-level domain (TLD) is the last segment of a domain name, such as .com, .org, or .net. A second-level domain (SLD) is the part of a domain name that comes before the TLD, such as "example" in example.com. A subdomain is an additional segment that comes before the second-level domain, such as "blog" in blog.example.com.

NETWORK SECURITY AND PRIVACY

Network security is the protection of computer networks and their data from unauthorized access, misuse, or theft. It involves implementing policies, procedures, and technologies to safeguard the integrity, confidentiality, and availability of information on a network. Privacy, on the other hand, refers to the protection of personal information, ensuring that sensitive data is not disclosed without the individual's consent.

Firewalls, antivirus software, encryption, virtual private networks (VPNs), secure password policies, two-factor authentication, and regular software updates are some ways to prevent threats to network security and privacy.

CONCLUSION

Computer networking plays a crucial role in modern communication and information sharing. Understanding its types, topologies, protocols, and security measures is essential for effectively utilizing this technology. As the internet continues to evolve, it is vital for individuals and organizations to stay informed and adapt to the ever-changing landscape of computer networking. In conclusion, highlight the key points discussed in the blog, emphasize the importance of the topic, and explore the subject further.

Thankyou

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