Content Delivery Network System (CDN)

A CDN is a network of servers located around the World. Its primary purpose is to make your static, dynamic and streaming content to load faster.


What are the different types of content?

  • Static: Javascript, CSS, and images

  • Dynamic: content generated by the web server normally using Ruby, PHP or javascript.

  • Streaming: any audio/video files

When a user requests an asset from a web server, the server locates the asset and delivers it back to the user. Classically this involve either locating the asset in the one location it’s stored (in the case of static or steaming content), or generates it on-demand (in the case of dynamic content.

If you’re using a CDN, content will be duplicated to servers around the world, and the user’s request will be directed to the geographically closest server. This leads to far less latency when requesting assets, leading to page elements loading much faster.

Why is the server response time important?

  • Increased bounce rate. Server response time has a direct effect on page loading speed. Your website could be losing huge amounts of traffic if the pages take too long to load. According to Google, 53% of people will close the page if it takes more than 3 seconds to load.

  • A decrease in search ranking. Increased bounce rate will make Googlebot think that content on the page is poor quality and you will drop down within Google search soon enough.

What does server response time depend on?

  • Poor quality web hosting. Using legacy or underpowered software/hardware will most likely lead to longer response time.

  • Traffic overload. At peak times when your website is getting large volumes of traffic reaching the capacity level of your server, users can experience significant page loading delays or even a 509 error (bandwidth limit exceeded).

  • Bloated web pages. if your website does not follow at least the most common optimisation practices it will take longer for the page to load. Some of the most important things to consider are minifying JS and CSS files, optimising images, not using non-responsive or oversized images and unnecessary gifs.

  • Not enough caching. If you intend to improve your website loading speed and reduce unnecessary waiting, enable browser caching. Server response will be much faster if a browser extracts previously loaded elements from the local cache rather then loading the same elements multiple times. Additionally server-side caching can improve the load times of dynamic content, even if the user hasn’t visited the site before.

Benefits of using CDN

  • Preventing traffic overload. Loading different pieces of content from separate servers will be less likely to cause server traffic overload, as all traffic will be split between the servers, rather than overwhelming a single server.  

  • Decreased latency. Latency is a time period between when a user makes a request to a server and when they get a response. Lower latency time means that page load times will improve.

  • Data centre distribution. A CDN will help to localise your website, reducing the chances a user having to access information from a single server which may be geographically far away, for example, having to travel transatlantic. The information will be extracted from local data centres, helping any content to load faster.

  • Improved reliability. Loading media content faster may allow users to enjoy it in a higher quality - lower latency and faster load times could mean that a user is able watch a video in HD where they may otherwise have only been able to watch it in SD, leading to increased user satisfaction.

  • A CDN might turn out to be a cheaper option for you. Having one system that distributes your site information worldwide is often more cost effective than paying for the bandwidth from your main server to send the content around the globe.

  • Protection against DDoS. Attacks like this may damage your reputation and lead to financial loses. A CDN can help keep the website running as they act as an extra line of defence, with many designed in such a way to stop a DDoS attack before it reaches the main server.

As we all know, for any business consumer, satisfaction is key. Your website will be penalised by Google if the pages take too long to load. Once you’ve been penalised there is a long and complicated process of getting your trust back.

Your site will benefit most from implementing CDN if any of these apply to your business:

  • your site is targeted at a worldwide audience

  • you get large traffic spikes

  • content on your website includes large audio/video files  

  • you’re streaming live videos

Contact us if you’d like to find out more about how CDN can benefit your website, and if you need help implementing it!