CDN - What is a Content Delivery Network (CDN) and how does CDN work

Learn how a content delivery network (CDN) works and its benefits

The OVHcloud CDN enables you to improve your website's performance and file download speeds, using OVHcloud points of presence (PoPs) distributed worldwide. Reduced latency enables you to optimise conversion rates and improve SEO.

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Key Benefits

Increased security, improved speed, and better user experience

Removing your server from the front line and letting the CDN Infrastructure solution manage traffic reduces risks of attack by allowing the network to absorb more requests. When employing a CDN, you are less exposed to vulnerabilities.

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SEO optimisation for each country

Increase search scores with SEO optimisation for each country with a point of presence. CDN Infrastructure provides the advantage of accelerating page loading times and enhancing website and application responsiveness. This greatly improves the user experience.

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Reduced hosting costs and faster ROI (Return On Investment)

No need to purchase more hardware to serve more content. CDN Infrastructure manages your growing traffic needs for you. Your back-end server is solicited less, reducing your computing costs. You will also be geographically closer to your end-users, therefore, using fewer resources.

What is a CDN?

A CDN (Content Delivery Network) is made up of a group of servers in various locations around the globe. These locations are called points of presence (PoP). Following rules defined by you,  they redistribute the content of your servers locally by caching files that do not need to be updated regularly.

This simple principle boosts and optimises your international websites while improving the user experience for your worldwide audience.

Why use CDN Infrastructure?

OVHcloud's CDN Infrastructure solution provides many advantages for your traffic and conversion rates. The content delivery network speeds up your site and puts content closer to your visitors, regardless of where they are located in the world. This is accomplished by replicating content across multiple servers.

Data transfer is quicker and latency time (which can be very long for users located on other continents) is significantly reduced. CDN Infrastructure gives your site a competitive edge, by enhancing performance and improving your search engine ranking in the process.

Another advantage of the OVHcloud Infrastructure solution is that it also works as a shield for your website by blocking external threats (abusive crawls, DDoS attacks).

Discover the many advantages of OVHcloud's CDN Infrastructure solution

How CDN works in 3 steps

Step 1 : Your users access your content from anywhere in the world


Requests are made to the DNS servers. With IP Anycast technology, the CDN redirects requests to the OVHcloud CDN PoP closest to the user, with the shortest latency.

For example, if your user is based in Montreal, they will be redirected to the PoP in Beauharnois, Canada as it is the closest point of presence within their proximity.

Step 2 : Sending files to the user and communication between the CDN and your servers

Once the CDN request is sent to the user, there are 3 possibilities:

  1. The requested files have not yet been cached on this CDN PoP. The CDN retrieves them from your Cloud Storage and sends them from the PoP to your user.
  2. The requested files are available in cache on the PoP (using your rules) and are forwarded without needing to call on your hosting servers resulting in using less bandwidth and fewer resources.
  3. The requested files or pages are either dynamic content or not within your cache rules. The CDN directs the request to your server to return the requested content to the user.

When the time to live (TTL) of the cached files has expired, the CDN will clear the cache and fill it the next time a vistor requests the file.


Step 3 : The user returns: your site is faster!


When the visitor requests this page again, the nearest CDN point delivers the static content directly from the cache, without calling on your servers.

You can set a TTL for your files so that the CDN PoP verifies the information before distributing it. If the TTL has expired, it will request the content from your hosting servers.


Without the CDN, the user request in Fort Worth, Texas would take a much longer route on every connection to your website, relating to the distance from your website hosting location.

If your site is hosted in France, the loading time would be quite long. As you'll see, the advantage of the CDN is reduced latency achieved by bringing your sites and applications closer to your visitors, and as a result, relieving the load on your hosting servers and reducing the use of bandwidth.


How to start using the CDN Infrastructure

Follow these 3 steps and start using the CDN Infrastructure:

1. Declare your domain names. We generate a Let's Encrypt SSL certificate for you if you don't have your own.

2. Set your origin server's IP address for each domain.

3. Update your DNS to set CDN Infrastructure as your frontend.

Start using our CDN with your infrastructure right now

CDN Infrastructure is compatible with your OVHcloud's services such as our Dedicated Servers or Virtual Private Servers (VPS)
or on-premise servers and even with a third-party cloud service provider.

You can start with a 1, 3, 6 or 12 month(s) initial subscription.


What is Static content?

Static content of a web page is comprised of all the elements that are not subject to dynamic updates. Generally, static content includes, but not limited to, images, videos, static html, and audio. A static page is a generic page that is the same for all users of the web application. The data is requested without customisation.

What is a Dynamic page?

A dynamic page is generated specifically for a user by the web application upon receiving the request.

What is a PoP?

The "Point of Presence" represents the local caches based in Europe and North America. Each PoP has its own cache, so it can deliver content locally to your users.

What is a CDN cache and TTL?

Each PoP has its own local cache. The content can be requested by all users of your site routed to this point. The content will be refreshed automatically by the value declared by the time to live (TTL). TTL is a parameter that enables you to define the time that data is retained in the PoP's cache.

What is a Backend?

Backends are the actual hosting services of your web applications. These sources will be used by the PoP for the cache. For OVHcloud web hosting backends, please consider the integrated CDN option.

What is IP Anycast?

A web application pointing to an IP Anycast is routed in a specific manner. When a user requests a page, the request is automatically directed to the nearest PoP.

What is a Configuration rule or a Cache rule?

Configuration rules allow you to manage the caching and the TTL of your web applications. They are available via your Control Panel or the OVHcloud API.