Posted on May 27, 2014

What is a CDN?

What is a CDN?


You have lots of different options when considering a hosting solution for your business. But having a fast and efficient website does not always end with choosing a reliable web hosting provider. There are other things that you can put in place and one of those things is a CDN. But what is a CDN? The abbreviation stands for Content Delivery Network which is a surprisingly accurate description (normally computer and internet terms are as easy to decipher as the mating call of the blue whale). But to understand what a CDN does you first need to understand the problem that it solves.


So here is an explanation:


The problem is similar to problems experienced by people making international phone calls 20 years ago: delays on the line. If you are too young to remember back then you will probably still have seen the problem. It often happens on news programs where the presenter is talking to someone in a foreign country, usually one that is poor or war-stricken. What they sometimes experience during those conversations is a delay on the line.


It is a frustrating experience as it takes a lot of self-discipline to say "Hello" and then wait 2 to 3 seconds for the person on the other end to respond. The natural urge is to assume they didn't hear you and to say something else. But that just confuses things even more to the point that both parties stumble through half sentences and awkward silences as the delay rules the call.


Website Delays


Browsing websites internationally has some similarities. Typically your website will live on a server located in the US. When a visitor from another country accesses your website it is the server in the US that sends it. The distance that the website is traveling to get from your server to your visitor on the other side of the world can cause delays of several seconds.


A CDN overcomes this problem. It works by mirroring your website across several different servers all over the world. When a visitor accesses your website, the CDN looks at their location and selects the closest server that has a mirror copy of your website. Your visitors see nothing different or unusual but they will experience a faster loading website.


High Traffic and Traffic Spikes


Effectively dealing with high volumes of traffic is another benefit of having a CDN set up on your website. When your website is on a single server it has finite resources. This comes into focus when you have a spike in traffic as you can quickly use up the server resources available and your website can become sluggish and can even crash. A CDN can help with sudden spikes in traffic.


It does this because it can deliver your website to users from a choice of several different locations. So if one part of the CDN is suffering from a high load it can divert your users to another part. Again your visitors will not notice anything except that your website loads quickly and things like videos don’t jitter or buffer.


Big websites like Microsoft, Google and Facebook employ CDN technology which is one of the reasons why their services are usually so reliable, despite high traffic volumes, spikes, and users across the world.


Is a CDN for Me?


A CDN is a powerful solution for making websites as fast and efficient as possible but they are not required in all situations. If you have a low traffic website or if most of your users are local a CDN is unlikely to benefit your business. On the other hand if you do get frequent spikes in traffic, or if you have visitors from around the world, a CDN is something to consider.