Effective page load times are perhaps one of the most vital elements of any website to get right. Whenever possible, you should be looking for ways to shave off even a hundred milliseconds or two from your site's load times, anything to make your pages load faster.

While the difference of a couple of hundred milliseconds might not sound like a major concern, with page load times, even an extra half a second delay on your load times could be enough to convince a user to hit the back button or close their browser altogether. In fact, studies have shown that as little as an extra one-second delay in page loading time can cause a 7% deduction in conversion for e-commerce sites.

The blunt truth is that, if your website takes more than a second or two to load, most people are going to move onto another site. but one way in which you can get around this problem and improve your page load times is with a CDN.

What does CDN stand for?

If you're wondering 'what is a CDN?', it's quite simple. CDN stands for Content Delivery Network. But what is a content delivery network?

In broad terms, a content network is group of geographically distributed dedicated servers that work together to increase the speed of an internet connection. Put simply, they minimise the physical distance between a user's request and the end server.

To accomplish this, a content delivery network stores a cached version of the content that's being requested in various dedicated server locations around the globe. These locations are called 'points of presence', or PoPs.

These PoPs all hold a cached version of the webpage or site in question. When a request for the content is made, the content network works out where the request is coming from, and then looks for the PoP that is closest geographically to the request's IP. This negates the need to send the request all the way from the UK to Australia, for example. Instead, the request will go to the nearest PoP to access the content, therefore minimising latency and page load times.

How does a content network work?

There are two distinct configurations for content delivery network technology: push and pull. The main difference between them is the stage in the request process where the content is served to the content network, meaning you have two options to choose from when setting up your servers.

After setting up a pull content network configuration for a web server hosted in the UK, the very first time a content request is made, the CDN has to figure out which PoP is closest.

Once this is achieved, the PoP then pulls the content from the host server before presenting it to the user. From that point, the cached content is available on the user's nearest PoP to be served locally.

With a push content network, the content is pushed out to the PoPs from the start. A push CDN doesn’t have to wait for the request to be made. The advantage of this is that the first user doesn’t have to wait for the extra step of the content moving from the host server to the local CDN.

However, it's worth noting that the additional delay on a pull content delivery network configuration is only for the first user in that geographic location. All subsequent users in the area are presented with the cached version as normal.

This can actually make pull content networks easier to set up as they require less configuration than initially, and less effort to keep the content up to date. When updates are made on a push content delivery network on the host server, there can be a delay of up to 15 minutes before the content is updated on all of the PoPs in the content network. During this time, a user could either see outdated content or a ‘file not found’ page, causing them to move to a different website.

Why use a content delivery network?

The most obvious and important reason to invest in a content delivery network is for the improvement of your page load speeds.

In many cases, a four-second page load time could be decreased to two seconds with cached content on a properly configured content delivery network. This has immediately obvious benefits for metrics such as bounce rates, page views, and conversion rates. Remember, 25% of users will bounce if a page takes more than four seconds to load.

But a content network can also be used for load balancing when a webpage is seeing a surge in traffic. If the content is being pulled from the same PoP location because the surge in traffic is all local, a content delivery network can help manage this by redirecting traffice to another PoP.

Although the latency will increase because there’s more physical distance between the request and PoP, and you'll have to configure the content network to account for load balancing persistence, the page load time will remain lower because there’s less load on both PoPs.

Finally, content delivery network technology also allows for a layer of improved security. Because server requests are effectively coming through a proxy in the form of the PoPs, a content delivery network can be configured to protect your servers from malicious requests like denial-of-service attacks.

The CDN can tell if the request is malicious based on things like its IP address and payload, as well as the frequency and volume of its requests. As the content delivery network is ‘outside’ of the host server, it can block these requests, leaving the host server unaffected.

How to set up your own CDN

It's possible to construct and self-host your own content delivery network, but in many cases, you can find excellent content network services out there for your own personal use.

Of course, if you plan on self-hosting your own content network, then you'll need more than just a set of dedicated servers. At Fasthosts, we provide excellent web hosting and cloud server options at great prices. Our cloud servers let you choose between servers in the UK, Germany, Spain, and North America, meaning you can have as many PoPs as you need to help balance your user traffic.

But it's not just cloud and server services that we handle. We can also provide domain names, WordPress hosting, and website building for anyone looking to set themselves and their business up online.

If you want even more information about how to improve your internet browsing and website setup, why not take a a look at our detailed articles and guides over on the Fasthosts blog.