A computer network is the interconnection of several computers, switches, routers, hubs, firewalls, smartphones, etc. To understand the computer networking basics, you need to understand at least a few important things such as computer network architecture, basic building blocks of any computer network, different communication models and services which can run on any computer network.

Let’s see different fundamentals or basics of computer networking in detail.

What is computer network?

A computer network is the interconnection of several computers in a particular network structure. Each computer in the network can communicate with each other with the help of interfaces, services, and protocols.

A computer network aids in sharing or exchanging of data resources. The entire networked infrastructure which serves the end-users is called the internet. You can even connect the internal computer network with an outside network, such as the internet.

The information of internal network can be made available over the internet in various content formats such as plain text, audio-visual content, images, etc.

The flow of data is bidirectional, and even any computer of internal network can access any information from the internet using a Uniform Resource Locator (URL) or a link to the internet.

Computer networks architectures

To understand the networking basics, you need to have some idea about network architecture. The network architecture is an underlying design or an arrangement of the computers to enable a reliable and robust communication over the networks. It follows certain principles, rules, and procedures for the network communication.

The computer network architecture is broadly classified into

  • Peer to Peer  architecture
  • Client-Server architecture
  • Layered architecture

Peer to Peer architecture (P2P Model)

This P2P model consists of several computational nodes or machines. This model lacks a central control system and instead each computer available on the network acts as a server to either processes or stores the relevant files and information.

There is no hierarchy of the machines in the network, and thus, the work is shared by all resources equally in the network. If a computer connected to the network fails to operate, then the other resource picks up the tasks of the failed computer and continues to work.

The installation of the P2P model is easy, and it is widely used for the file sharing purposes.

Client-Server architecture (Tiered Model)

In this model, a server placed at the highest level in the hierarchy. The server is usually a high-end computer with more speed, memory, and performance. It acts as a centralized system to which other computers, called clients, are connected.

These servers run their own operating systems which handles the networking tasks. A server receives requests from several clients connected to it over the network. After, either processing or storing the information of the request, the server responds to the clients.

A server also manages the resource allocation, provides services to the clients, ensures the security of all available data and provides backup and recovery mechanisms, enables the transactions, etc.

A server can be accessed from any device and any location across multiple platforms through the applications. A client can access as many servers as it needs. Thus, it is always “1: Many” network relationship between the server and clients. There are many different types of servers which are purely based on the client application.

Layered architecture (N-tiered protocol model)

This type of architecture is usually based on layers and protocols. These layers are well-stacked one above the other. The layered architecture is an open architecture which ensures the modularity of the intricate network design.

Each layer consists of protocols, services, and interfaces.

Services

Each lower-level layer provides its services to the next connected higher layer without disclosing the implementation details. Thus, the most top layer has a full set of services to manage and run various applications on the network. These services are further divided into Connection-oriented services and Connectionless services

Connection-oriented services: These services establish a connection to send a message. An acknowledgment is received for each transmitted signal over the network. Thus, these are reliable services.

Connectionless services: These services do not require a connection to send a message. The message can be sent directly anytime. An acknowledgment is not received, and each sent message over the network are delivered in any random order. Thus, these are unreliable services.

Protocols

Protocols are the set of rules or conventions that regulates and controls the communication between the layers of communication to exchange information. A series of protocols used by each layer is known as “Protocol stack.”

The layer N on one machine can communicate with layer N on another device indirectly. These machines are known as “Peers or Peer entities.” As the lowest layer is connected to the actual physical medium, these Peers communicate with each other through the lowest layers.

Interfaces

The interfaces are defined between any two adjacent layers. These interfaces contain the services and messages provided by one layer to the other.

Networking building blocks

There are different types of devices, systems, mechanisms, etc. which are available in the market that is essential for implementing any network architecture. The following is a few crucial building blocks of networking that makes it practically feasible and accessible in the real world.

They also constitute the essential practical elements of networking basics.

IP addresses

Every networking device on the network got to have an IP address for reference. IP stands for internet protocol, and it is the numeric address allocated uniquely to every possible device communicating over any IP enabled network.

Domain names

IP addresses are difficult to remember and thus domain name come into existence for attaching human-readable characters to the IP address. A user-friendly and straightforward name is assigned to the IP address of a server machine for quicker access and navigation.

Network switches

A network switch is a network device that behaves like a hub and connects various networking devices, such as computer, server, printer, firewall, etc., within the same network. Nowadays, smart switches are available in the market which has facilities like individual port blocking, port forwarding, etc.

Routers

It is an intelligent network device which bridges two or more networks working on the same protocol. Sometimes routers behave as DHCP (Dynamic Host configuration protocol) and automatically allocates IP address to different nodes on the network. It also chooses the best possible data packet to travel path and prioritize the connections.

Firewalls

These are the security keepers which blocks or filters out the suspicious traffic from entering into the network. They protect the system from any possible attack.

Gateways

These are similar to routers, and they connect devices present in two dissimilar networks using different protocols.

Wired technologies

Data ables are one of the earliest inventions that were used to transmit data among the connected devices in a network. Ethernet Cables are the conventional wired data transmitting medium. Other types are twisted pair wiring, coaxial cables, fiber optics cables, etc.

Hub

A network hub is an electronic device that acts as a connector on which various devices on a network are connected. Its primary purpose is to retransmit data to multiple nodes. The most common hub is an ethernet hub. USB hubs are other forms of network hubs.

Bridges

These are the devices used to connect different networks when the options of connecting through the routers or switches become unavailable.

Repeaters

It amplifies the signal strength for the data transmissions so that the signal can cover longer distances bypassing an obstruction.

Network adapters

It is an internal computer component used to connect to any other networking device in the network.

Modems

Modems encode and decode the signals for digital data transmissions. The types of available modems are cable modems, DSL and satellite modems.

Access points

It enables the Wireless networking. It extends the functionality of the router to connect to multiple devices.

Wireless technologies

Wireless technologies use different types of signals or waves, such as microwaves, radio waves, spread-spectrum techniques, radio communication technologies, satellite communication, etc., as transmission media.

These tools mentioned above are used appropriately either in combination or separately by the different layers of the network communication models such OSI and TCP/IP model.

Network communication models

Network models standardize network communications across different protocols and devices within different layers of communication in a sequential approach.

OSI model

The 7-layer Open Systems Interconnection (OSI) model is the widely known and prevalent reference model. Almost all network standards fit into the OSI model. It is used for operation specifications, data network design, and troubleshooting. The following are the layers available in the OSI model.

  1. Physical layer – This is the lowest layer of the stack, and it deals with physical connections and data signals types communicating with them. Examples are ethernet and fiber optic cables.
  2. Data link layer – This layer is above the physical layer, and it packages the incoming data bits into frames. It checks for any transmission errors in data and corrects them accordingly. A typical example is layer-2 network switches.
  3. Network layer – The concept of network layer talks about routing between two separate networks of similar type. Data is passed from data link layer in the form of frames, and they stay the same till they reach the destination.
    Once the data reaches the destination, this layer converts frames into data packets and further sends them to transport layer. An example is a router.
  4. Transport layer – It accepts information from the session layer and divides it into small chunks of data before passing it to the network layer.
    It either establishes or terminates the connections between the peers and also regulates the information flow between them. Examples are TCP and UDP protocols.
  5. Session layer – It is responsible for creating sessions among various users, connected to the network, through different machines.
    The feature of data synchronization inserts the checkpoints within the data stream for the possible data recovery during the system crash. Examples are NetBIOS, Named pipes, etc.
  6. Presentation layer – This layer checks the correctness of the syntax and semantics of the information during its transmission. This layer handles different data functions such encryption, decryption, compression, etc. Examples are GZIP, ASCII, JPEG, TIFF, etc.
  7. Application layer – This layer defines all the higher level application protocols used for user interaction such as HTTP, FTP, SMTP, IMAP, etc.

TCP/IP reference model

Though TCP/IP model is similar to OSI model, it is not a reduced version of OSI model. The TCP/IP model and OSI model evolved separately and are independent of each other.

The TCP/IP model aims to not only provides a flexible architectural network design but also binds multiple networks together to make them appear as a single network. The following are the layers in TCP/IP model –

  1. Host to network layer – Combination of the physical layer and data link layer of OSI model.
  2. Internet layer – This is similar to the network layer of the OSI model.
  3. Transport layer – This layer is responsible for the peer entity interaction, where the interaction is based on the TCP and UDP protocols.
  4. Application layer – This is similar to the application layer of the OSI model.

Computer network applications

A computer network facilitates easy means of efficient communication among users. Various popular and basic applications which require an efficient computer network are- instant messaging, online chat, email, video calling, video conferencing, online transactions, etc.

Users can access services using the shared resources available within the network such as access a shared network printer for printing a document or use a shared storage device. Authorized users of a network can share the files, data, and all other types of information.

A security hacker uses a computer network to either deploy the computer viruses on the devices connected to the network or prevents these devices from accessing the network.

Final words on networking basics

Computer networking basics cannot be summed up in this much of space as there so many other fundamentals. Although, we feel this much information is enough to give you a glimpse of networking basics.

Apart from whatever we covered, we suggest you refer additional topics such as network topology, communication standards & protocols, various network types based on the organizational structure & the geographical scale, network routing, network security, network performance & services, network planning and design, etc.