Computer Network

What is Computer Network?

A computer network means the interconnection of computing devices that helps in sharing resources and data based on a specific communications protocol over wired or wireless technologies. A computer network typically consists of different computers called nodes.

Understanding Computer Network

What is Network in Computer

Image Credit: Chris Woodford

The term computer networking signifies the interconnection of several computing devices called nodes.

This helps them in exchanging data between themselves as well as share resources when needed with each other.

Also known as networking simply, in a computer network, data is transported over a shared medium and comprises of several aspects such as:

This is a practice that enables connecting the endpoints or devices to each other on a LAN or Local Area Network to a larger network such as a private or internet Wide Area Network or WAN.

In simple words, a computer network involves a number of computers connected together in order to transport and exchange data and share resources.

This is not a new concept.

In fact, the idea of connecting different computers together was done way back in the 1960s when the Department of Defense created a computer network.

In this network, just a few computers were connected painstakingly around the United States.

After that, wireless networking was attempted and its success has made computer networking an integral part of computing today.

It is so omnipresent and useful today that a computer sans a network is arguably considered to have very little or no use in daily lives.

However, computer networking is not an easy task. It needs a lot of skills to set up and maintain the functionality of each node.

And, of course, there are several challenges to overcome right from the start down the road.

There are several important things to solve in networking which include and are not limited to:

However, the skill required to operate and maintain a network of computers directly will largely depend on the complexity of it.

For example, a network of a large enterprise will involve thousands of nodes which will need meticulous security such as end-to-end encryption.

This will call for professionals and expert network administrators to manage and supervise the network.

On the other hand, for a smaller network set up by a layperson would need performing basic troubleshooting knowledge which can be done even with the help of a brief instruction manual, for example, in the case of a home Wi-Fi network.

However, all these will need a thorough understanding of computer networking, right from the basics of it to the ‘more than the basic’ aspects, which are explained as under.

Basics of Computer Networking

Computer networking helps the businesses, service providers and consumers alike to share resources, communicate, and offer or use services all over the world.

Ideally, a computer can operate in two specific types of systems such as:

When multiple devices or media are involved in a communication among two different devices, these devices are referred to as network devices. These may include devices such as:

The devices connected to a network which forms the interconnection of multiple devices is also known as the hosts.

Several different paths are used to interlink the devices to the network through which data or media is sent or received.

Terms and Identifiers to Know

OSI or Open Systems Interconnection signifies the specific type of reference model.

It actually refers to the standards for communication protocols as well as the functions of every layer of the network.

Protocol refers to the set of algorithms or rules that describes the way in which two devices may communicate through the network.

In an OSI model, there can be many different such protocols defined for every layer of it such as:

There are also a few exclusive identifiers of a computer network that are also good to know and are mentioned below.

Host Name:

As said earlier, every device connected in a network is called the host and is usually assigned with a unique device name.

This name is commonly referred to as the Host Name.

You will be able to know the host name of the device you are using, if it is in a network, when you type “hostname” in the command prompt in the Administrator and hit ‘Enter.’

Internet Protocol Address:

Internet Protocol Address is also known as IP Address or Logical Address.

This indicates the network address of the system within the network which helps in the easy identification of a device in the World Wide Web.

Typically, every device on the internet is assigned with an IPv4 address or Internet Protocol Version 4 address by the IANA which is the short for the Internet Assigned Numbers Authority.

Usually, the length of the IPv4 address is 32 bits. Therefore, 232 IP addresses are available. On the other hand, the length of an IPv6 address is 128 bits.

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You can check the IP address of your device by typing “ipconfig” in the command prompt in the Administrator mode and hitting ‘Enter.’

Media Access Control Address:

Also known as MAC address or physical address, this refers to the unique identifier of the individual host and it is related with its Network Interface Card or NIC.

This particular address is allocated to the NIC during the time of manufacturing and is usually 12 nibbles or 6 bytes or 48 bits in length.

You can check the MAC address of your device by typing “ipconfig/all” in the command prompt and hitting ‘Enter.’

Port Number:

The term port here refers to the logical channel. This is through which the data is sent or received to an application.

There may be several applications running at the same time in any host and in order to identify each of these applications the port number of the host device on which it is running is used.

A port number is usually 16 bits in length and therefore there are 216 ports available.

These ports can be categorized according to the respective ranges of each type of ports such as:

You can know the port number of your computer by typing “netstat -a” in the command prompt and pressing ‘Enter.’

Socket:

This refers to the unique combination of the port number with the IP address of the device in a network.

DNS Server:

The full form of DNS is Domain Name System, which actually indicates the server that translates URLs or web addresses into their respective IP addresses.

This saves the users from the hassle of remembering the IP addresses of each and every website.

You can check the information of the DNS of your system by typing the command ‘nslookup’ in the command prompt and hitting ‘Enter.’

Apart from the DNS, you can also check the IP address of the domain you want in this way.

Address Resolution Protocol:

Commonly referred to as ARP, this is particularly used to convert the IP address to the equivalent physical address or MAC Address.

Usually, an ARP is used for identification of the MAC address of the device of the receiver by the Data Link Layer.

RARP:

A short for Reverse Address Resolution Protocol, RARP, just as the name suggests, offers the IP address of the system given a physical address as an input.

However, RARP is not used anymore these days because DHCP has replaced it.

Working Process

In computer networking the two primary building blocks are the nodes and links.

Here node refers to the Data Communication Equipment or DCE and may include devices such as:

A node may also refer to the Data Terminal Equipment or DTE that may include two or more printers, computers and others.

On the other hand, a link refers to the media for transmission of data between two nodes connected in the network.

The links can be either physical such as optical fibers and cable wires or wireless.

Ideally, in a computer network, the working process follows a specific set of protocols or rules.

These rules define the way in which the data is to be sent or received electronically through the links.

Also, the design of all of the physical and logical elements of the computer network is defined by the architecture.

Apart from the physical components, this also provides the specs for the procedures, functional organization, and protocols of the network.

Computer Network Topology

In a computer network, a specific layout arrangement is followed in order to connect the different devices to it or arrange the nodes and links.

This is called network topology and it can be of different types.

Here are some of the most common types of computer network topologies for you along with a brief description of each:

Each of these types of network topology comes with their respective pros and cons and therefore you should consider them before selecting one of them for your organization.

Different Types of Computer Network

There are different types of computer network architectures but it can be categorized into two broad groups in particular such as:

Client-Server Architecture

Just as the name suggests, in this particular type of computer network architecture the nodes connected can be either clients or servers.

In this architecture, the server nodes in particular provide different resources to the nodes such as:

The server nodes are also capable of managing the behavior of the client nodes, which typically do not share the resources while communicating with each other.

For example, in enterprise networks the computer systems that store configuration settings and data are referred to as the servers within the network.

The clients of the organization can access the data stored in them by simply after requesting the server computer.

Peer-to-Peer Architecture

Also referred to as P2P architecture, the computers that are connected in this network usually have the same power and enjoy the similar privileges.

In this network architecture there is no central server which may coordinate the computers.

Every single device in P2P computer network architecture can function like a client or a server by sharing a portion of the resources such as the processing power and memory of the whole computer network.

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For example, organizations use this type of architecture for hosting applications across several digital devices that consume a lot of memory such as 3D graphics rendering.

Based on these two broad categories of the architecture of computer networks, the enterprises set their computers according to the needs and size of their organization.

Depending on that particular parameter, the enterprise computer network can be further divided into three specific heads such as:

Local Area Network

Commonly known as LAN, this refers to the interconnected system in an organization that has size and geography limitations.

In this process the computers or other devices within a single building or office are connected with each other.

Apart from the small companies, LAN is also used as a test network for prototyping any small scale network.

Two or more personal computers are connected in this network through a twisted pair coaxial cable which helps in communicating.

The unique features of LAN are:

Wide Area Network

This is the most widely used computer network today and therefore needs explaining a bit more.

Commonly known as WAN, this refers to an enterprise network that spans over a few buildings or even over cities and countries.

This network can transmit data over a long distance quite quickly and is quite reliable and secure.

SD-WAN or Software-Defined Wireless Area Network is a specific type of WAN architecture that is virtually managed by software technologies.

This type of network is more flexible and reliable.

The connectivity services can be managed at the application level without compromising with the quality and security of service.

The unique features of Wide Area Network include:

The internet itself is the best example of a WAN, but other than that the list also includes:

There are several advantages of using a Wide Area Network which include:

However, there are some disadvantages of Wide Area Network such as:

Personal Area Network

Commonly referred to as PAN, Personal Area Network refers to the arrangement of computers by any individual usually within a small range of 10 meters.

These computers connected in the network are mostly for personal use.

This idea which was conceived first by a research scientist Thomas Zimmerman comes with a few specific features such as:

There are usually two specific types of Personal Area Network such as:

Some of the common examples of PAN are:

Metropolitan Area Network

A Metropolitan Area Network or MAN interconnects different LANs in a large geographic area to create a larger network with the help of a telephone exchange line.

Usually, the government agencies use MAN to connect to other private industries or the citizens.

MAN uses specific types of protocols but the most commonly used ones are:

Offering a much higher range as compared to LAN, a MAN is typically used for the following purposes:

Internetwork

This specific type of network involves two or more computer networks such as LANs or WANs. It can also include different segments of a computer network and connected together using different devices.

In addition to that, interconnection also refers to other computer networks such as:

These connected devices are configured with a local addressing scheme, a process typically called internetworking, and uses a specific internet protocol.

Depending on the connection, internetwork can be of different types such as:

Extranet

This is the lowest level of this type of networking. This is based on specific internet protocols such as Transmission Control protocol.

Used usually for sharing information, the access to this type of network is limited to those users only who have the actual login credentials.

An extranet can be classified as WAN, MAN, and other computer networks but cannot consist of one single LAN.

It should ideally have at least one connection to the external network.

Intranet

This is a private network that operates on specific internet protocols such as Transmission Control protocol and others.

This network belongs to the specific organization and can be accessed by the members or employees of that organization only.

The primary objective of setting up an intranet is to share resources and information among the employees of the organization since it facilitates working in a group or teleconferencing.

The unique advantages of intranet are:

Ideally, the service provider networks may also allow the users to rent functionality and capacity of the network from the provider.

These service providers may be any one of the following:

Cloud Networks

Cloud networks are conceptually the same as WAN in terms of the infrastructure of the cloud-based service.

An organization can host some or all of its resources and network capabilities in a private or a public cloud platform.

These resources can be used when required and can be anything such as:

Cloud networks expedite the time to market, manage costs and increase scale more effectively.

The cloud network model today is very useful and has become the norm for creating and offering applications to any modern enterprises.

Importance of Computer Network

Back in the 1950s, a computer network helped the military and defense to send secret information safely over telephone lines.

Over time, with the development of internet technologies, computer networks became important for both scientific as well as commercial applications, especially for the enterprises.

Today, computer networks offer much more than connectivity. It is important for digital transformation that ensures the success of businesses today.

With the enhancement of the underlying capabilities of the network that has made them much more secure, programmable, and automated, computer network today is important for the following reasons:

Most importantly, a computer network helps in extending interpersonal communications making the best use of the electronic means and different technologies. These include:

In short, a computer network makes life easy by exploiting the most out of the technology.

Advantages and Disadvantages of Computer Network

There are several advantages of using a computer network such as:

However, there are a few specific downsides of using a computer network which include:

Nevertheless, with proper use and maintenance, a computer network is very useful today and has become an integral part of computing especially for any large organization.

Conclusion

Now with that, almost every basic and more than the basic aspects of computer networking are covered in this article.

By now you surely have no more doubt about the importance of a computer network and will find it easy to choose a particular setup for your organization very quickly and confidently.