What is a CDN and why is it important to use it?

As a result of research and statistics, it was established that a user can wait up to 9 seconds for a page to load, then, if there is no result, the user closes it. Therefore, on the scene comes CDN (Content Delivery Network), which is becoming one of the most important tools for website owners. Let's take a look at what a CDN is, how it works, and why using it is critical for any business that wants to stay ahead of the game.

What is CDN?

In simple terms, a CDN is a network of servers located around the world that serve to cache and quickly deliver website content. The idea is to speed up data access for users, regardless of where the server hosting is physically located. Instead of sending each request to your main server (origin server), a CDN routes requests to the closest server on the network, which significantly reduces response time and speeds up loading.

Imagine you have a visitor from Japan and your server is located in Ukraine. Without using a CDN, its requests would travel a long time across continents, which would slow down the site loading. Now imagine that this content is cached on a server in Tokyo — the user will get access to your site much faster. This is the magic of a CDN.

How does CDN infrastructure work?

To understand how this network works, let's look at its main elements:

1. Origin server — this is your main server where all the content is stored. For example, your website, videos, images, etc. When someone requests content that is not yet on the CDN servers, the request is forwarded to the origin server, and only then is the content cached on the edge servers.

2. Edge servers — these are servers that are located all over the world and cache content initially downloaded from the origin server. They are responsible for speeding up the delivery of data, being as close to the user as possible.

3. PoP (Points of Presence) — Points of presence, where edge servers are located. These points are strategically distributed around the world to ensure maximum coverage and performance. For example, the SIDATA provider may have PoPs in key cities in Europe and Asia, which allows them to effectively serve users from different regions.

How does loading a page from a CDN actually happen?

Imagine that your website is running on a server in Kyiv, but you have many users from the US. Without a CDN, requests will go across the ocean, taking longer and increasing latency. But if you use our servers, users in the US will have their requests processed by the closest servers, for example, in New York or San Francisco. As a result, the page will load faster, and visitors will be happy.

How does CDN work?

Let's look at a simplified process of how a CDN works:

1. The user enters your website address into the browser.
2. The browser sends a request to the DNS server to determine the IP address.
3. If your site is configured to use a CDN, the DNS server returns the IP address of the closest PoP.
4. The request is sent to the edge server, which checks whether the required content is in the cache.
5. If the content is already cached, it is immediately returned to the user. If not, the request is passed to the origin server and then cached on the edge server for subsequent requests.

What benefits do you get by using a CDN?

Using a CDN not only helps speed up your website, VPS, but also solves several other serious problems:

• Reducing server load. If you have a lot of visitors, requests can overload the main server. With a CDN, most of the traffic is redirected to edge servers, which reduces the load.

• Protection against DDoS attacks. Many CDNs offer built-in solutions to protect against DDoS attacks and other threats, such as web firewalls and SSL/TLS encryption.

• SEO Optimization. A fast loading site has a positive effect on search engine rankings. Google and other search engines take loading speed into account when determining search engine rankings.

• Reliability and fault tolerance. If one server fails, the CDN can redirect traffic to another, ensuring uninterrupted operation.
• Scalability. CDN automatically handles traffic surges, which is critical for advertising campaigns or during major promotions.

Examples of CDN use

1. Sites with a global audience: If you have an online store and your customers are located in different countries, using a CDN can reduce loading times for all users, regardless of their location.

2. Streaming and multimedia: For sites with a lot of video content, CDN is a must-have. For example, if you are posting educational video courses or live broadcasts, then with CDN the content will be delivered faster and without delays.

3. Mobile applications: For traffic-intensive applications, CDN helps reduce latency, ensuring smooth performance even under heavy load.

When should you consider using a CDN?

Using a CDN is not necessary for everyone, but if your site loads slowly for users from other countries, or you often experience sudden traffic surges, this is already a reason to think about implementing a CDN from SIDATA. This will help you not only speed up your site, but also save on resources and protect it from possible attacks.

Services offering CDN

The CDN services market is quite large, and finding the right solution can be challenging. It is important to choose a service that provides the optimal combination of speed, reliability, and security. Let's look at a few popular providers:

1. Cloudflare

Cloudflare is one of the most well-known and popular CDN providers, which offers a wide range of features to speed up and protect websites.

• Free plan with basic features for small sites.
• Encryption support and built-in DDoS protection.
• Additional performance optimization tools, including automatic image optimization and file size reduction.

However, for sites with high traffic volumes and special speed requirements, free options may not be enough and you will need to upgrade to paid plans.

2. Akamai

Akamai is one of the oldest and largest CDN providers on the market. It is focused on serving large corporations and projects with high loads.

• A vast network of thousands of servers worldwide.
• Powerful security and analytics features.
• Suitable for large sites and corporate clients with high requirements for reliability and speed.

Despite its capabilities, Akamai can be overkill and too expensive for small companies and startups.

3. Amazon CloudFront

Amazon CloudFront is a CDN service from Amazon Web Services (AWS) that is ideal for those already using Amazon's cloud offerings.

• Deep integration with other AWS services such as S3, EC2, and Route 53.
• Wide customization and scalability options.
• HTTPS support and built-in attack protection mechanisms.

However, for those new to the world of AWS, using CloudFront can be challenging due to the abundance of settings and the high complexity of the interface.

4. Fast

Fastly is a high-performance CDN provider that focuses on minimizing latency and supporting dynamic content.

• High response speed and flexibility in customization.
• Capabilities for delivering streaming video and complex web applications.
• Suitable for media platforms and e-commerce.

Fastly is more suitable for advanced users who need deep customization and high performance.

Speed is of the essence these days. If you want to stay competitive and attract more users, a CDN is a tool worth adding to your website’s arsenal.