Why use a CDN – Content Delivery Network

This post is a follow-up to a question by one of the consultants this month via email.

A CDN is referred to as a Content Delivery Network.  In reality a network of servers that distribute your files across the globe in order to make the accessing of information faster when loading into a website or intranet.  They are used to hold various different types of file and are primarily to build a level of redundancy and also speed to a website.

When a website loads information it can only load a certain number of items at once, typically this is limited to 4 in most browsers.  So the 5th item is held until one of the previous 4 has been downloaded.  A CDN provides a different domain to load data from and hence it expands the number of files that can be accessed at any one time.  Some designers implement this when building a site by making use of sub-domains such as media.domain.co.uk and images.domain.co.uk to load data quicker within a website.

One of the main benefits is  access to files quicker due to the information being replicated across multiple servers around the globe, resulting in data being drawn from the server that is more local to the user.

There articles provided may give you some guidance on the pros and cons.

The answer I’ve got to the question: Should I use a CDN is …  It depends.

In practice site owners are already making use of them without probably knowing as a selection of key files are typically downloaded into the website from Google’s servers and the inclusion of video from YouTube is already one step in the right direction.

Article 1 – Should you use a CDN

Article 2 – 11 questions about CDNs