All you ever wanted to know about cloud computing: Content Delivery Networks

Phil Muncaster

Tuesday 20 January 2015

Content Delivery Networks are a vital part of the fabric of the internet, but many firms don’t know what they do. We take a closer look at how they could help your business

Have you heard of Content Delivery Networks (CDN)? Services like Akamai, Amazon CloudFront and Fastly are leading the charge for this relatively young industry that aims to improve website performance. A CDN consists of a network of web servers, often scattered across the globe, which serve up cached content to users in the immediate vicinity. When a user requests a web page which is being served by a CDN, the network will redirect the request from the original site’s server to one of the CDN servers. The geographical proximity enables faster content delivery, improving availability and reducing bandwidth.

CDNs are being used by a variety of organizations today, as most customer-facing firms would benefit from faster, more reliable, websites. However, they are most popular with companies where fast content delivery is mission critical, for example: media, e-commerce, gaming and communication providers. CDNs also protect against large surges in traffic, and some providers such as Akamai have even begun to specialize in preventing distributed denial of service (DDoS) attacks designed to crash the sites of their customers.

Benefits of investing in a CDN

1) Page loading speeds are now as a ranking factor for Google search results

2) Improved availability

3) Lower latency

4) Reduced bandwidth usage

5) Improved user experience

Not for everyone

Not all firms need CDNs. Those who expect that most visitors to their site live close by might feel the extra investment can’t be justified. Equally, those firms operating within industries where latency is not likely to be a deal-breaker for customers may feel the same way.

There are also several disadvantages that may provide barriers to adoption, including:

1) Lack of control: Changes to web content must be made via the CDN, increasing the admin burden

2) Costs: Charges vary depending on the provider and the type of content you want delivering, but they can soon become significant.

3) Trust: Introducing a third party into your hosting set-up might present issues for some firms. You will be using a resource shared with other customers so due diligence is important when choosing a provider to satisfy service levels and security requirements.

4) Availability: Some regimes around the world, notably in China, have begun blocking some popular CDNs wholesale as they look to crack down on specific content. In a worst case scenario, your site could end up as collateral damage.

Ultimately, individual firms must establish their own priorities, and decide whether or not to make use of CDNs based on the exact nature of their business and on their desired profile on the Internet.