Content delivery networks
A CDN (this is the short term of content delivery network) is a system where computers are interconnected on the Net providing content very fast to a large number of users. The process happens by copying the loaded content on different servers, located on multiple geograpical places then directing it to users on proximity criterias.
When somebody is accessing a website or a specific webpage being a part of a CDN, that request will be redirected from the site’s server to a CDN server (the closest servers to the user) and then the content will be delivered.
Using a CDN is very recommended (for improving speed) when delivering informations from websites with heavy traffic from different parts of the world. A very important thing is to have a very good geographical server distribution. This way the content can be fast delivered to people accessing the website from all over the world, at the same time. This technology brings a lot of advantages when we are talking about audio-video streaming and IPTV.
When using a CDN the content will be delivered without any delay even if multiple end users are accessing the same website or content simultaneously. Excessive latency is taken down to a minimum and this is noticed when you have a powerfull Internet connection.
I can mention here another advantage of CDN and that is the data backup option, archiving the content, and offering a huge storage capacity. Companies focusing on online data backup solutions will be the biggest group taking advantage of these features.
The costs of using a CDN can be high for small companies or websites but proven when the number of your users is growing and more important it’s geographicaly spreading. This way you’ll solve the slow response time issues. Think about this: 90% of the users response time is when they wait for all the components in a webpage to be loaded: scripts, flash content, videos/images. .
You maychoose a CDN based on the population methods it supports. There are two categories when choosing a CDN considering the audience’s methods it supports: push and pull.
1. The first one -Pull- it’s easier to manipulate as it doesn’t require a lot of work from your side: Just rewrite the URLs to your files: replace your domain name with the CDN’s domain name. The Pull technique is applied by the CDN and this way the files from your server will be periodically pulled out.
2. The second one -Push- needs a bit of an effort from your side to synchronize the files to the CDN. This method has the advantage of being flexible because you have the option to decide the time when files will be synchronized, how often and what other preprocessing actions will be performed.
- Virtually no setup
- No flexibility
- Redundant traffic
- FTP, SFTP
- No redundant traffic
One thing to be mentioned is that some contend delivery networks, if not most, are able to handle Origin Pull and one (ormore) Push methods.
Professional Streaming Consultant