A Content Delivery Network (CDN) consists of networked computers across the Internet that cooperate to make available the content or data (usually large and static) to users. The network consists of: origin servers, where the content is pushed into the CDN to be replicated; geographically distributed nodes where content is replicated (CDN); and from routing mechanism allowing a user query on a content to be served by the node “closest” in order to optimize data transmission.
The optimization results in a reduction in bandwidth costs on your origin server (static content, images, style sheets, JS and videos are managed by the CDN) and improving the experience user (the site is loaded faster).
To give an example, YouTube videos are replicated to dozens of thousands of computers distributed networks in the world. So when you upload a video, the closest group of computers will be responsible for transmitting video. Thus, the total bandwidth is shared between several thousand computers, and the content is conveyed faster.
The main advantages of using CDN:
- Fast loading of web sites
- Saving capacity (ideal for websites with high traffic or with strictly limited virtual hosting).
- Reduction the load on the hosting server
The benefits of CDNs
The rate of data transfer is quite strongly influenced by the distance it is from the user to the website. This is because for downloading files in the global network protocol is TCP / IP. Here, the delay of information transfer depends on a finite quantity of places that are between the client and the server. Usage of CDN reduces the number of transitive areas (transitions), so clients will have significantly fewer delays while downloading files, and the transfer rate will hold steady at a high level without sudden jumps. This stability enables service providers and operators to ensure the delivery of video content in high definition (HD), fast downloading files, and organize broadcasting videos with minimal network and the highest quality of service.
The content gets better and takes up more space. Clients are accustomed to images in high resolution, so attempts to increase page-speed by reducing the quality of the content is ineffective.
The most important thing is not related with IT: every little thing affects the perception of the brand. Slow loading site hangs the label on business: “slow”, and will not help the brand manager. A slow site means slow business.
Trying to choose the CDN-provider users opinion is based on two considerations: the price and the capacity. From the viewpoint of the speed is better to choose a geographically close provider to the target audience. We made a comparative list of prices and quantity of Point of Presence (PoPs), but we couldn’t find the needed information about pricing of some companies, they keep it private.
List of CDN Providers
Соmpany |
Price per 1 TB, from |
Number of PoPs |
Akamai |
$350 |
1450 |
Amazon Cloudfront |
$120 |
50 |
Azure |
$120 |
24 |
BitGravity |
$150 |
19 |
Cachefly |
$100 |
47 |
CDNetworks |
N/A |
41 |
CDNsun |
$45 |
70 |
EdgeCast |
$213 |
37 |
Fastly |
$120 |
21 |
Highwinds |
N/A |
24 |
Limelight |
N/A |
900 |
Every year websites are becoming “heavier” and CDN – more important. Over the past 9 years, the average weight of the pages of the online store has increased from 626 KB to 1677 KB. So much average page of online store weighed in 2014. For this reason, CDN is becoming increasingly popular in eCommerce. CDN technology is already used by a quarter of the top 100 online stores in US and Europe, because speed of the site is a powerful increasing sales factor.
No matter you are a software provider, a blogger who wants to post videos with low buffering time for their readers or the owner of an online store, what is important it is the comfort of your clients – content delivery network will help you to make your service better!