What is CDN and why is it crucial for businesses?

Users need the website to load in under two seconds because every additional second of wait time lowers conversion and customer loyalty by 7% and 16%, respectively. Connecting a CDN is one method for accelerating a website.
In this article, we define a CDN, describe the technology, and discuss how businesses can benefit from it.

How does a CDN work?

Websites on the Internet are typically hosted on servers that are situated in a particular geographic area. A user connects to this server and communicates with it in order to access a resource. The user's browser will take longer to load content the farther away the server is.

A content delivery network in the form of a geographically dispersed server and network infrastructure is known as a CDN (Content Delivery Network). In essence, extra components—intermediate nodes that store the required content—appear between the main server and the user. Since they are closer to the user, information exchange happens more quickly.

If you use hosting without a CDN, content delivery occurs in four stages:

• the user opens the site;
• the browser sends a request to the server where the data is stored;
• the server processes the request and starts sending data to the user;
• the page is loading.

The content is kept on intermediary caching servers positioned in various locations when a CDN is connected to a web resource or website. Additionally, the user from Mumbai connects to his CDN server in the Bengaluru rather than New York. The website loads more quickly because the route to the server is shorter.

Why you should use a CDN

After connecting the CDN for the site:

• the site loads quickly - users do not have to wait long for the pages to be displayed;
• the site increases throughput - it works correctly even with a large number of requests;
• the load on the source server is reduced - you do not have to buy additional equipment;
• increased protection against DDoS attacks - it will be more difficult for attackers to affect the availability of your site, because requests from a hacker are processed not by one server, but by the whole network;
• Optimization for search engines improves - the site will be displayed higher in search results.

Who can't do without a CDN

You cannot do without a CDN when:

• you need to quickly and regularly deliver content to a large number of users;
• users from different regions download static content from websites;
• the load on the infrastructure can dynamically change due to promotions or the growth of the project's popularity.

CDN is suitable for any company with clients in different regions of the country or the world.

• Internet shops. Page loading speed affects sales and site ranking in search engines. When connected to a CDN, the site works faster and more stable even with an increase in the number of requests, for example, during sales periods.
• Distributors of software and games. CDN helps to distribute application updates faster and streams the necessary content for online multiplayer games. With a CDN, all users receive content at the same time.
• Financial institutions and banks . For companies in the financial sector, website and application acceleration using a CDN helps improve online banking and get rid of delays in transactions. In addition, the technology provides additional protection against DDoS attacks.
• streaming services. CDN allows you to deliver high-quality content without delay, offload server capacity even at peak loads, and increase the fault tolerance of Live broadcasting services.

Own CDN vs ready-made solution: what to choose

You can create and configure your own CDN server (cdn-server). But this requires full-time or outsourced specialists who:

• buy or rent equipment and set up network infrastructure;
• register a domain and order a server;
• set up CDN DNS;
• install SSL certificates;
• install and configure a load balancer;
• check how the CDN works.

This process is complicated - creating a CDN service will not work quickly and without large investments. Creating your own CDN-hosting is only rational if existing solutions are not suitable in terms of security, price or availability.

For most, it is more profitable to buy a ready-made solution from a CDN provider. In this case, to connect the CDN network to the site, you only need:

• register on the provider's website and indicate the address of the domain of your website in your personal account;
• replace the addresses on the site with new ones generated after receiving the CDN configuration.

Ready-made solutions are easier and cheaper to use. They are versatile and suitable for almost any task.

How to choose a CDN provider

Now CDN services are offered by many providers, but each service has its own characteristics. To choose a CDN for your tasks, you need to take into account some parameters.

• Number of intermediate nodes. The more points of presence and the wider the geography of their location, the better. But the geography of intermediate nodes should correspond to the distribution of the audience - for example, points of presence in USA are not needed if the site is aimed at Indians.
• Additional services. Along with the most distributed content delivery network, CDN providers also offer other services: consumption analysis, caching policy and HTTP header management, preloading of very “heavy” content, full and selective cache clearing. They will help you flexibly configure your CDN and increase the speed of loading large amounts of data.
• Support for protocols and technologies. It is important that the content delivery network (CDN) supports the required technologies: HTTP/2, IPv6, SSL certificates, and others.
• Support quality. It is important that the provider's specialists respond quickly to requests and can help in any situation. It is best if they can help both experienced users and beginners - for example, they can tell you about CDN in an accessible way: what it is and how it works.

Main topic

1. CDN is a geo-distributed server and network infrastructure that allows you to quickly deliver content to users.
2. Using a CDN provides a number of benefits, from speeding up the site and reducing the load on the central server to increasing protection against DDoS attacks.
3. CDN is useful for any business that cares about site availability and content delivery speed.
4. You can create and set up a CDN yourself, but it's difficult and expensive. It is easier to use ready-made solutions.