INTRODUCTION TO COMPUTER NETWORKING
INTRODUCTION TO COMPUTER NETWORKING

What Is Networking?

A network is simply a collection of computers or other hardware devices that are connected together, either physically or logically, using special hardware and software, to allow them to exchange information and cooperate.
 

Networking is the term that describes the processes involved in designing, implementing, upgrading, managing and otherwise working with networks and network technologies.

How does a computer network work?

Nodes and links are the basic building blocks in computer networking. A network node may be data communication equipment (DCE) such as a modem, hub or, switch, or data terminal equipment (DTE) such as two or more computers and printers. A link refers to the transmission media connecting two nodes. Links may be physical, like cable wires or optical fibers, or free space used by wireless networks.

In a working computer network, nodes follow a set of rules or protocols that define how to send and receive electronic data via the links. The computer network architecture defines the design of these physical and logical components. It provides the specifications for the network’s physical components, functional organization, protocols, and procedures.

What do computer networks do?

Computer networks were first created in the late 1950s for use in the military and defense. They were initially used to transmit data over telephone lines and had limited commercial and scientific applications. With the advent of internet technologies, a computer network has become indispensable for enterprises.

Modern-day network solutions deliver more than connectivity. They are critical for the digital transformation and success of businesses today. Underlying network capabilities have become more programmable, automated, and secure.

Modern computer networks can:

Operate virtually

The underlying physical network infrastructure can be logically partitioned to create multiple "overlay" networks. In an overlay computer network, the nodes are virtually linked, and data can be transmitted between them through multiple physical paths. For example, many enterprise networks are overlaid on the internet.

Integrate on a large scale

Modern networking services connect physically distributed computer networks. These services can optimize network functions through automation and monitoring to create one large-scale, high-performance network. Network services can be scaled up or down based on demand.

Respond quickly to changing conditions

Many computer networks are software-defined. Traffic can be routed and controlled centrally using a digital interface. These computer networks support virtual traffic management.

Provide data security

All networking solutions come with in-built security features like encryption and access control. Third-party solutions like antivirus software, firewalls, and antimalware can be integrated to make the network more secure.

What are the types of computer network architecture?

Computer network design falls under two broad categories:

1. Client-server architecture

In this type of computer network, nodes may be servers or clients. Server nodes provide resources like memory, processing power, or data to client nodes. Server nodes may also manage client node behavior. Clients may communicate with each other, but they do not share resources. For example, some computer devices in enterprise networks store data and configuration settings. These devices are the servers in the network. Clients may access this data by making a request to the server machine.

2. Peer-to-peer architecture

In Peer-to-Peer (P2P) architecture, connected computers have equal powers and privileges. There is no central server for coordination. Each device in the computer network can act as either client or server. Each peer may share some of its resources, like memory and processing power, with the entire computer network. For example, some companies use P2P architecture to host memory-consuming applications, such as 3-D graphic rendering, across multiple digital devices.

What is network topology?

The arrangement of nodes and links is called network topology. They can be configured in different ways to get different outcomes. Some types of network topologies are:

Bus topology
Each node is linked to one other node only. Data transmission over the network connections occurs in one direction.

Ring topology
Each node is linked to two other nodes, forming a ring. Data can flow bi-directionally. However,single node failure can bring down the entire network.

Star topology
A central server node is linked to multiple client network devices. This topology performs better as data doesn’t have to go through each node. It is also more reliable.

Mesh topology
Every node is connected to many other nodes. In a full mesh topology, every node is connected to every other node in the network.

What are the types of enterprise computer networks?

Depending on the organization's size and requirements, there are three common types of enterprise private networks:

Local area network (LAN)

A LAN is an interconnected system limited in size and geography. It typically connects computers and devices within a single office or building. It is used by small companies or as a test network for small-scale prototyping.

Wide area networks (WAN)

An enterprise network spanning buildings, cities, and even countries, is called a wide area network (WAN). While local area networks are used to transmit data at higher speeds within close proximity, WANs are set up for long-distance communication that is secure and dependable.

SD-WAN or software-defined WAN is virtual WAN architecture controlled by software technologies. An SD-WAN offers more flexible and dependable connectivity services that can be controlled at the application level without sacrificing security and quality of service.

Service provider networks

Service provider networks allow customers to lease network capacity and functionality from the provider. Network service providers may consist of telecommunications companies, data carriers, wireless communications providers, Internet service providers, and cable television operators offering high-speed Internet access.

Cloud networks

Conceptually, a cloud network can be seen as a WAN with its infrastructure delivered by a cloud-based service. Some or all of an organization’s network capabilities and resources are hosted in a public or private cloud platform and made available on demand. These network resources can include virtual routers, firewalls, bandwidth, and network management software, with other tools and functions available as required.

Businesses today use cloud networks to accelerate time-to-market, increase scale, and manage costs effectively. The cloud network model has become the standard approach for building and delivering applications for modern enterprises.

Here are essential computer network components:

Switches
Switches work as a controller which connects computers, printers, and other hardware devices to a network in a campus or a building.

It allows devices on your network to communicate with each other, as well as with other networks. It helps you to share resources and reduce the costing of any organization.

Routers
Routers help you to connect with multiple networks. It enables you to share a single internet connection with multiple devices and saves money. This networking component acts as a dispatcher, which allows you to analyze data sent across a network. It automatically selects the best route for data to travel and send it on its way.

Servers:
Servers are computers that hold shared programs, files, and the network operating system. Servers allow access to network resources to all the users of the network.

Clients:
Clients are computer devices which access and uses the network as well as shares network resources. They are also users of the network, as they can send and receive requests from the server.

Transmission Media:
Transmission media is a carrier used to interconnect computers in a network, such as coaxial cable, twisted-pair wire, and optical fiber cable. It is also known as links, channels, or lines.

Access points
Access points allow devices to connect to the wireless network without cables. A wireless network allows you to bring new devices and provides flexible support to mobile users.

Shared Data:
Shared data are data which is shared between the clients such as data files, printer access programs, and email.

Network Interface Card:
Network Interface card sends, receives data, and controls data flow between the computer and the network.

Local Operating System:
A local OS which helps personal computers to access files, print to a local printer and uses one or more disk and CD drives which are located on the computer.

Network Operating System:
The network operating system is a program which runs on computers and servers. It allows the computers to communicate via network.

Protocol:
A protocol is the set of defined rules that allows two entities to communicate across the network. Some standard protocols used for this purpose are IP, TCP, UDP, FTP, etc.

Hub:
Hub is a device that splits network connection into multiple computers. It acts a distribution center so whenever a computer requests any information from a computer or from the network it sends the request to the hub through a cable. The hub will receive the request and transmit it to the entire network.

LAN Cable:
Local Area Network(LAN) cable is also called as Ethernet or data cable. It is used for connecting a device to the internet.

OSI:
OSI stands for Open Systems Interconnection. It is a reference model which allows you to specify standards for communications.

Unique Identifiers of Network
Below given are some unique network identifiers:

Hostname:
Every device of the network is associated with a unique device, which is called hostname.

IP Address:
IP (Internet Protocol) address is as a unique identifier for each device on the Internet. Length of the IP address is 32-bits. IPv6 address is 128 bits.

DNS Server:
DNS stands for Domain Name System. It is a server which translates URL or web addresses into their corresponding IP addresses.

MAC Address:
MAC (Media Access Control Address) is known as a physical address is a unique identifier of each host and is associated with the NIC (Network Interface Card). General length of MAC address is : 12-digit/ 6 bytes/ 48 bits

Port:
Port is a logical channel which allows network users to send or receive data to an application. Every host can have multiple applications running. Each of these applications are identified using the port number on which they are running.

Uses of Computer Networks

Here are some common application of computer networks
  • Helps you to share resource such as printers
  • Allows you to share expensive software’s and database among network participants
  • Provides fast and effective communication from one computer to another computer
  • Helps you to exchange data and information among users via a network.

Advantages of Computer Networking

Here are the fundamental benefits/pros of using Computer Networking:
  • Helps you to connect with multiple computers together to send and receive information when accessing the network.
  • Helps you to share printers, scanners, and email.
  • Helps you to share information at very fast speed
  • Electronic communication is more efficient and less expensive than without the network.

Disadvantages of Computer Networking

Here are drawbacks/ cons of using computer networks:
  • Investment for hardware and software can be costly for initial set-up
  • If you don’t take proper security precautions like file encryption, firewalls then your data will be at risk.
  • Some components of the network design may not last for many years, and it will become useless or malfunction and need to be replaced.
  • Requires time for constant administration
  • Frequent server failure and issues of regular cable faults