What is Content Delivery Network (CDN)?

Content Delivery Network or CDN is a system of interconnected computers in the internet that is intended to provide instant and rapid web content to an unlimited number of users through the duplication of content on multiple servers. This content can then be delivered rapidly to any user around the globe by role of proximity. The role of proximity follows the principle of the closest server delivering the content to the user. The CDN technology is mostly used by Internet Service Providers (ISPs) in delivering both dynamic and static web pages but it is better suited in the delivery of streamed audios and videos including Internet Television or ITV programs.

How does CDN work?

The efficiency of CDN relies on the process known simply as content replication. Content replication is the process where multiple copies of the same content are dispersed into strategically located servers all over the network. The number of servers that contain the same content depends upon how large or small the CDN is, meaning a very large CDN may have a thousand or more servers, able to provide the same content to as many users as possible with the same efficiency and reliability regardless of the volume of traffic at any given moment.

As the delivery is based on proximity, any specific page, program or file requested will be delivered by the server closest to that specific user. The network dynamically determines which server is closest to that user based on the number of nodes. By the way, a node is a point of connection, either for redistribution or an end point for data transmissions. The closest server then delivers the content to the user, at an optimum speed and reliability.

Aside from the speed and reliability of delivery, how is CDN advantageous?

If you use CDN technology, you will enjoy the following advantages:

  • The ability to provide the same content at the same instant to a number of users. This also means an increase in the traffic your website will receive and a reciprocal increase in the earnings of your website.
  • The content redundancy guarantees that your data is safe even during large scale attacks and/or malfunction and damage of the internet.
  • As the load is distributed in a lot of servers, load on individuals servers are reduced which frees up resources and ensures optimum power;
  • A faster delivery of content from the nearest server available to the user; and
  • A guarantee that content is always available, that is anytime, anywhere, -as content is dispersed and distributed to a lot of servers-;

What then are the disadvantages of CDN?

Despite the advantages that CDN brings, just like any other technology, it has its own issues and drawbacks. The following are the most common drawbacks of CDN:

  • The need to provide servers at strategic locations around the world makes CDN impractical for small-sized and medium-sized companies. The question would be, “Can small and medium-sized companies shoulder the burden of actually installing servers at strategic locations?”
  • The second disadvantages rises from the need of installing servers around the world, which would then entail a huge and significant amount of investment. To solve the problem of installing servers at strategic location, companies would have to rely on third-parties to provide the service at locations beyond their reach. This would entail additional cost;
  • As CDN relies on third-party networks, the question of the availability of technical support would be problematic? How often does the third-party update their software to suit your service? How prompt can their technical support attend to issues and glitches?