Networking Basic Concepts and Fundamentals Explained

This tutorial explains the basic and fundamental concepts of computer networking. Learn the essential of computer networking such as types of computer network, network topologies, network cables, Ethernet standards, data transmission methods, network segments, protocols and several other networking terms in detail.

Computer networking is one of the most complex subjects. Describing all of its topics requires an encyclopedia. Learning and understanding all these topics at primary stage are neither required nor recommended. It is just like learning vocabulary from dictionary. Unless you know what you need to know, you would not learn what you should learn.

This tutorial helps you in picking and learning the right topics at initial stage. Understanding these topics will set the foundation for the rest of your studies.

So without any more intros, let’s start exploring the basic and fundamental concepts of computer networking.

Computer Networking

A computer network is a group of two or more computers connected with each other for data and resource sharing. A small computer network may contain only two computers while a large computer may contain several thousand computers. Computer networking is a process which explains how computers connect with each other in network and what technology and hardware they use to connect.

Type of Computer Network

A computer network is categorized based on its location and characteristic. Based on geographical location, some popular computer networks are listed below.

LAN

LAN stands for Local Area Network. It represents a computer network which spans in a small geographical area such as home network, office network, cyber café, WI–FI zone, etc.

MAN

MAN stands for Metropolitan Area Network. It represents a computer network which spans in a city or connects two or more different LAN networks such as Cable Network, Campus network, university network, etc.

WAN

WAN stands for Wide Area Network. It represents a computer network which spans over a large geographical area such as ISPs Network, MNCs network, etc.

Based characteristics, some well-known computer networks are outlined below.

Internet

Internet is the largest computer network ever made. It is a public network and not owned by any government, organization or company. Anyone with any type of device is allowed to connect with this network.

Intranet

Intranet is an IP based private network. It is owned and administrated by an individual body such as a company or an organization. In this network external users are not allowed to access the internal resources.

Extranet

Extranet is an extended Intranet. In this network, external users such as suppliers, buyer, vendors and customers are allowed to access a small portion of network for business purpose.

Network Topology

A network topology defines the layout of a computer network. There are two types of network topologies; physical and logical. The physical topology defines how computers are physically connected with each other in network while a logical topology defines how computers exchange data over a physical topology.

Bus Topology

In this topology, a single coaxial cable (known as trunk, backbone or segment) is used to connect all systems together. Bus topology provides a cost effective solution to build a computer network. It only uses a coaxial cable and few connectors. Due to its low cost, it was one of the most popular topologies in earlier days of computer networking.

The biggest disadvantage of this topology is that if there is a break in main cable, entire network will be down.

bus topology

In modern times, this topology is no longer used in computer network.

Star Topology

In this topology, a centralized device usually a hub or a switch is used to connect all systems together. Systems connect with centralized device through their individual cables.

In positive side, if there is any break in any cable, only the system which is connected by that cable will be down. In negative side, if centralized device is failed, entire network will be down.

star topology

Start topology is the most popular and highly used topology in modern times.

Star topology and Bus topology both use logically bus topology to exchange the data across the network.

Point to point and point to multipoint

These terms defines how systems exchange data with other systems. If data sent by a source system is only received by a destination system, it is a point to point connection. If data sent by a source system is received by multiple or all systems in network, it is a point to multipoint connection.

Network segment

Network segment is the group of computers which need a network connectivity device such as router or bridge to communicate with other computers in network. The process of breaking a large network in multiple networks (segments) is known as network segmentation. Network segmentation is done to improve the performance of overall network. A network divided in segments performs much faster than a single network.

Following figure shows a large network divided in three network segments.

network segment

Network media

Network media provides connectivity between two systems. There are two primary types of network media; wireless media and cable media.

In Wireless media radio spectrums are used to connect the systems.

In cable media, a cable is used to connect the systems. There are three primary types of cable which are mainly used in computer network; coaxial cable, twisted-pair cable and fiber optic cable.

Coaxial cable

This cable is mainly used in bus topology. Since bus topology is no longer used in building a computer network, you will hardly ever see a computer connected with this cable in real world. Still you should learn the specification of this cable for exam and interview purpose. There are two types of coaxial cable; Thinnet and Thicknet.

coaxial cable

Following table lists the characteristics of both cables.

Type Grade Specification Supported Length Thickness Data Transfer speed Required connector Used for
Thinnet RG-58 185 Meter 0.25 inch 10 Mbps BNC Drop cable
Thicknet RG-8 500 Meter 0.50 inch 10 Mbps AUI Backbone cable

Twisted-pair cable

In computer network cabling, twisted-pair cable is the king. This cable has total eight wires in four pairs (4x2). Each wire of the pair is twisted around the other wires. Twists help cable to reduce the crosstalk. There are two types of twisted-pair cable; UTP (unshielded twisted-pair) and STP (shielded twisted-pair). STP is little bit expensive than UTP but provides higher data transmission rate over the long distance.

twisted pair cable

STP cable has higher quality and more protective jacket in comparison of UTP cable. Besides this, STP also wraps wires and pairs with foil to make it less susceptible to EMI (Electro-Magnetic Interface).

Fiber-optic cable

Fiber-optic cable is used for long distance. Just like coaxial cable and twisted-pair cable, fiber-optic cable also has two types; single-mode and multi-mode.

fiber optic cable

Single-mode fiber optic cable uses a single ray of light to transmit the data while Multi-mode fiber optic cable uses multiple rays of light simultaneously to transmit the data.

Key points
  • Coaxial cable is no longer used in computer network.
  • Coaxial cable and twisted-pair cable use copper wire to transmit the data.
  • Fiber-optic cable uses a thin layer of glass to transmit the data.
  • Coaxial cable and twisted-pair cable are used for shorter distance.
  • Fiber-optic cable is used for longer distance.

To learn more about the cable and cabling standards see this tutorial.

Network cable types and specifications

It explains network cables in details with their specification.

Broadband and baseband

These two terms define the technique that is used in transmitting the signals.

In Baseband, signals are sent in digital form through a single channel. This channel uses the entire bandwidth of media. Baseband provides bidirectional communication which means same channel can send and receive data simultaneously.

In Broadband, signals are sent in analog form through multiple channels. Each channel uses its assigned frequency to transmit the data. Broadband provides unidirectional communication which means a channel can either send or receive data at a time. To perform both operation at a time, either two cable or two parallel channels are used; one for sending and other for receiving.

Duplex mode

Duplex mode shows how a device can send or receive data. There are two types of duplex mode; half duplex and full duplex. In half duplex mode, a device can either send or receive data at a time while in full duplex mode a device can perform both operations at the same time.

Ethernet

The term Ethernet defines the network architecture. It explains the speed, technology, cable and several other factors of network.

ethernet standard

Following table lists some popular Ethernet standards.

Ethernet Speed Technology Cable Supported distance
10Base2 10Mbps Baseband Coaxial 200 meter
10Base5 10Mbps Baseband Coaxial 500 meter
10BaseT 10Mbps Baseband UTP/STP 100 meter
10BaseFL 10Mbps Baseband Fiber-optic 100 meter
100BaseTX 100Mbps Baseband UTP/STP 100 meter
100BaseFX 100Mbps Baseband Fiber-optic 100 meter

For a complete list of all Ethernet standards, see this tutorial. It explains Ethernet standard in details.

Ethernet Standards explained

Protocols

Protocols are the predefined rules which computers use to communicate with each other. Protocols are usually associated with specific services or tasks. Protocols perform several tasks such as connecting with remote computer, providing logical addresses in network, broadcasting messages, initializing and terminating sessions, providing authentication and encryption, performing error correction and a lot more other things. Without protocols computer does not send a single byte of data in network.

Following tutorial explains protocols and their functionality in detail.

Types of Network protocols Explained

OSI Layers model

OSI (Open system Interconnection) Layers model is a logical model which explains how two computers communicate with each other. It breaks entire communication process in seven layers; application layer, presentation layer, session layer, transport payer, network layer, data link layer and physical layer. Each layer explains a specific portion of communication process.

To learn more about the OSI layers model and its functionality, you may see this tutorial

OSI Seven Layers explained

It explains OSI layer model and its layers in detail.

That’s all for this tutorial. It’s really very hard to select the topics for an introductory tutorial especially when subject is so vast. Still I tried my level best to select and explain the most basic terms and concepts of networking. Where it was possible, I included a link of article which explains that particular topic in more detail. If you have any suggestion or feedback about this tutorial, please mail me. If you like this tutorial, share it with your friends through your favorite social network.

ComputerNetworkingNotes Networking Tutorials Networking Basic Concepts and Fundamentals Explained