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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.
- Computer networking allows the devices within the network to follow a specific system of rules which is called the communications protocols.
- Networking of computers facilitates transmission of data and information by using both physical as well as wireless technologies.
- Computer networking facilitates several things such as making telephone calls, text messaging, streaming video, and may include Internet of Things or IoT as well.
Understanding Computer Network
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:
- Policies and
- Function of the network infrastructure.
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:
- Scaling of hardware and software to a very high speed level often in excess of 100 GB/s
- Use of routers, switches and more
- Effective web technologies to use for a better interaction with the users
- Adequate safety and security along with privacy protection with antivirus software, firewalls, and more
- Being able to meet the ever increasing wireless demand due to the use of smartphones and handheld devices
- Coping up with the social phenomena effectively
- Scaling and effectively managing a large number of users often over a billion using Internet of Things, sensors and others
- Preserving healthy Internet economics between the service providers and
- Offering seamless connection to the mobile devices.
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:
- In an open system where it is linked with the network and is ready to communicate and
- In a closed system where it is not connected to a network and therefore cannot be communicated with readily.
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:
- Hubs and
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:
- TCP OR Transmission Control Protocol
- IP or Internet Protocol
- UDP or User Datagram Protocol
- ARP or Address Resolution Protocol
- DHCP or Dynamic Host Configuration Protocol
- FTP or File transfer protocol and so on.
There are also a few exclusive identifiers of a computer network that are also good to know and are mentioned below.
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.
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.’
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:
- Well known ports – 0 to 1023
- Registered ports – 1024 to 49151
- Ephemeral ports – 49152 to 65535
You can know the port number of your computer by typing “netstat -a” in the command prompt and pressing ‘Enter.’
This refers to the unique combination of the port number with the IP address of the device in a network.
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.
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.
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 modem
- A hub or
- A switch.
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:
- Bus topology – In this arrangement, each node is connected to the other only. This means that data is transmitted in this type of arrangement of nodes in only one particular direction.
- Ring topology – In this arrangement, each node is connected to two other nodes which form a ring. Data in this type of arrangement flows in two directions. However, in this case if one node fails, it will bring down the entire network.
- Star topology – In this arrangement, there is a central server node that is connected to several client network devices. The nodes in this type of arrangement perform much better because the data does not need to pass through every node which also makes this topology a bit more reliable.
- Mesh topology – In this arrangement, each node is linked with several other nodes and in a full mesh arrangement, each of the nodes is linked with every other node within the network.
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:
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:
- Processing power
- Memory and
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.
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.
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:
- It is less expensive since the hardware used to build it such as network adapters, hubs and Ethernet cable is inexpensive
- It allows faster data transfer and
- It provides high security.
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:
- It covers a large geographical area
- It uses telephone line, satellite link or fiber optic cable for data transfer
- It is widely used in the fields of education, government, and business.
The internet itself is the best example of a WAN, but other than that the list also includes:
- Mobile broadband such as a 4G network
- Last mile, which is a telecom company that connects hundreds of homes and cities with fiber to provide the internet services and
- Private network that connects several branch offices like in a bank through a dedicated leased telephone line from the telecom company.
There are several advantages of using a Wide Area Network which include:
- Centralized data, which means that the users do not need backup servers, files or emails
- Updated files, which means that the files with be updated by the programmers within seconds by working on the live server
- Faster exchange of messages just as you do through Facebook, Whatsapp, and Skype
- Easy sharing of software and other resources such as RAM or Random Access Memory and hard drive
- Operating business on a global scale with the use of internet and
- Higher bandwidth that enhances the rate of data transfer and thereby the productivity of the company.
However, there are some disadvantages of Wide Area Network such as:
- There can be security issues due to combination of several technologies together
- There is a need of firewall and antivirus software to keep hackers and viruses away from the systems
- High installation cost due to its need for a number of specific hardware such as routers and switches and
- Troubleshooting issues.
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:
- It can cover an area of up to about 30 feet and
- Only personal computer devices such as laptops, mobile phones, media players and play stations are used to build a PAN.
There are usually two specific types of Personal Area Network such as:
- Wired Personal Area Network which is created usually by using a Universal Serial Bus or USB and
- Wireless Personal Area Network which is built by using wireless technologies such as Bluetooth and Wi-Fi but supports a low range.
Some of the common examples of PAN are:
- Body Area Network which is like a mobile network moving with a person
- Offline Network which is created within the home and is hence called a home network that typically integrates other devices such as computer, printer, or TV without needing internet connection and
- Small Home Office network which connects different devices to the internet as well as to the corporate network by using a VPN or Virtual Private Network.
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:
- RS 232 or Recommended Standard 232
- Frame Relay
- ATM or Asynchronous Transfer Mode
- ISDN Integrated Services Digital Network
- OC 3or Optical Carrier 3
- ADSL or Asymmetric Digital Subscriber Line and others.
Offering a much higher range as compared to LAN, a MAN is typically used for the following purposes:
- For communicating between different branches of a bank within the city
- For airline reservation
- In the colleges within the city and
- For communication in the military.
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:
- Private networks
- Public networks
- Commercial networks
- Government networks and
- Industrial networks.
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:
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.
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:
- Cheaper and easier communication between employees through email and chat
- Time saving because information is shared in real time
- Collaboration due to distributed information that can be accessed by authorized users only
- Platform independency due to the neutral architecture which allows connecting the computer to another device by using a different architecture and
- Cost effective since duplicate copies of documents and data can be seen over the intranet by using the browser since these are distributed.
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:
- A telecommunications company
- A data carrier
- A wireless communications provider
- An internet service provider and
- A cable television operator that offers high-speed internet access.
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:
- Virtual routers
- Network management software and
- Other tools and functions.
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:
- It allows operating virtually because the physical infrastructure underlying the network can be partitioned logically to create several overlay networks. Here the nodes are linked virtually and it allows passing data through these nodes by using several physical paths.
- It allows integrating on a large scale by distributing the network which allows optimizing its functions. It allows better monitoring of resources through automation to build a single, high-performance, large-scale network which can be scaled up or down according to the requirements.
- It allows responding quickly to shifting conditions being software-defined. This helps in routing and controlling the traffic centrally with the use of a digital interface. This actually supports virtual traffic management.
- It offers higher security to data due to the security features built in them such as access control and encryption. You can also use different third-party solutions such as firewalls, antivirus software, antimalware and others to integrate into the network to make it more secure.
Most importantly, a computer network helps in extending interpersonal communications making the best use of the electronic means and different technologies. These include:
- Online chat
- Instant messaging
- Voice calls
- Video telephone calls
- Video conferencing and more.
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:
- It is a reliable and quick way to share resources and information between users
- It helps in making the most out of the IT systems
- It allows using the peripheral devices connected to it such as printers, copiers and scanners remotely by several users
- It saves money and time by sharing one single internet connection
- It helps in increasing the storage capacity with so many available in the several computers
- It helps the employees to share information and communicate more easily
- It makes businesses more efficient and productive by accessing common database without needing typing in the same data again and again which saves time and prevents errors as well
- It allows easy sharing of customer data and feedback to offer better customer service
- It offers a centralized storage that reduces cost and increases efficiency
- It allows users access control which prevents data leak or theft
- It allows workgroup computing enabling faster production
- It needs less IT support due to centralized network management which reduces cost and time and
- It reduces the cost of buying site software licenses because several standalone licenses are not required.
However, there are a few specific downsides of using a computer network which include:
- Additional cost on hardware
- Expensive management
- Additional cost on training and on a network manager
- Files on the file server will be inaccessible if it breaks down
- Viruses can spread easily and quickly across all computers
- Risks of hacking in WANs in particular
- It needs time and expertise in administrative support
- There are chances of the cables breaking that may change the configuration of the whole network and result in a complete failure and
- Security and compliance issues exist.
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.
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.