A Content Shipping and delivery Network or Content Supply Network, abbreviated to CDN, is a network of computers that can contain copies of information. Computers on the CDN can request data they don't already have from other computers on the network that then can be delivered.
If, for example, someone wanted to do a live video transmitted from London that has site visitors from around the globe attempting to watch at the same time. This would put a massive load on the streaming server delivering the media, in this example a video stream. Picture if the viewers of this webcast wanted to watch from Australia, New York, Los Angeles and Japan. The streaming storage space working in london would have to broadcast this live movie stream to all those locations which means the video streams would have to 'hop' many times before reaching their destinations on the various regions. Dedicated Streaming Server This compromises the rate of delivery and sets a massive load on the internet connection being employed by the streaming server. It also means the video clip stream may experience 'packet corruption' or even 'packet loss' meaning the quality of the video being watched could be affected. This is more relevant if the broadcast is using UDP. When the broadcast is being done over TCP there are more 'load' issues because there is a regular communication between server and client.
Therefore the answer to this issue is to have a 'Point of origin' server that takes the original video stream, which in turn passes it on to 'Point of presence' servers, or PoPs, around the world after request. So now our streaming server in London does not have to deliver to Australia, New York, Los Angeles and Japan as in our above example. A visitor that could like to watch the video stream in Australia would use the same online player as people in London to watch it, but now the player is looking at a CDN for a stream rather than the single streaming server in London. The CDN would know from the requesting IP address that the request is approaching from Australia and would request the video supply from a 'Point of presence' server nearest to Australia. If that stream does not exist, probably because it has not been requested from this location before, the 'Point of presence' machine would request it from the 'Origin server'. This specific process would be the same for the viewers in Ny, Los Angeles and Japan.
The benefits of this are that the workload to broadcast the video stream is balanced across many servers rather than just one. The bandwidth is also balanced because all the streams are not coming from the same source, which means more concurrent users can view the video supply with much larger stability. Just about all the CDN servers, the 'Point of origin' and the 'point of existence servers', are strategically put around the world with an internet backbone making the delivery speed between servers very fast and reliable.
Articles delivery networks are not bound to only sharing the load of video and audio tracks streams. We could share images and PDF files in the same way. In fact any digital media can be requested over a CDN. Our company is not only restricted to media being distributed over a CDN, websites can be cached which obviously makes for faster delivery around the world. This will be significant for corporate websites which may have millions of visits.
Another benefit of utilizing a CDN is that once your digital media is on the 'Origin' servers or on the 'Point of presence' servers, it is effectively backed up. If the client requests data from a CDN server that is down, the CDN can make a request to another machine on the network and is still able deliver the media.
The last thing I actually would like to point out about using Content Delivery Networks is usually that the 'Point of origin' servers can be your company's machines in your company's storage space farm. They do not have to be a CDN server. This practice is not recommended by most CDN's as it is more likely to be your company's storage space that is down or experiencing connection issues rather than a CDN storage space. The one benefit of having your own 'Point of origin' server could it be does allow you to maintain local backups of your content if you need to.