How Content Delivery Network Works?
Media Entertainment Tech Outlook | Monday, September 13, 2021
The content delivery networks is aware that all of a streaming service's movies are stored on several servers, each with its own IP address
FREMONT, CA: Content Delivery Networks, or CDNs, are globally distributed servers that are essential in live video and VOD streaming infrastructures. A CDN lies between video players (clients) and origin servers, delivering video content across geographical regions and scaling efficiently to provide clients with a seamless viewing experience.
Video Streaming Architecture
The steps below are the same for most live and VOD streaming designs.
A transcoder receives the source video and processes it.
The video is resized and compressed by the transcoder into various bitrate-resolution combinations (called Profiles).
The compressed movies are transmitted to a packager, where they are prepared for transmission using ABR technologies.
After that, the packed videos (chunks and manifests/playlists) are saved on a streaming server or origin server. Finally, the video URLs are published on the CMS and made available to the apps.
When a user pushes the play button on a video, the origin server replies to the players' requests and sends the needed chunks.
How CDNs Work
The packaged videos (perhaps HLS or DASH) are saved on the origin server, and the CDN is informed of their location. As a result, the CDN is aware that all of a streaming service's movies are stored on several servers, each with its own IP address.
The video players are then set to request the video from the CDN rather than the Origin Server. As a result, the CDN's URLs are delivered to the players.
When the CDN receives the first play request, it is likely that the content is not in its cache. As a result, it makes the request to the Origin Server, and when the Origin responds, it caches the material and transmits it to the player.
The CDN examines its cache to see if it already has the same video segment cached the next time another video player (or the same one!) requests it. If yes, the CDN serves the video from its cache; if not, the CDN requests that the segment be sent to it from the origin server.