Content delivery network
Introduction
Content delivery networks (CDN) distribute delivery of contents over a network of proxi servers, i.e. allow distributing contents in a much more efficient way that from a single data center. Large scale distribution of "heavy" contents, e.g. videos used in MOOCs would not work without CDN.
“A content delivery network or content distribution network (CDN) is a geographically distributed network of proxy servers and their data centers. The goal is to distribute service spatially relative to end-users to provide high availability and high performance. CDNs serve a large portion of the Internet content today, including web objects (text, graphics and scripts), downloadable objects (media files, software, documents), applications (e-commerce, portals), live streaming media, on-demand streaming media, and social networks. CDNs are a layer in the internet ecosystem. Content owners such as media companies and e-commerce vendors pay CDN operators to deliver their content to their end users. In turn, a CDN pays ISPs, carriers, and network operators for hosting its servers in their data centers. The term CDN is an umbrella term spanning different types of content delivery services: video streaming, software downloads, web and mobile content acceleration, licensed/managed CDN, transparent caching, and services to measure CDN performance, load balancing, multi-CDN switching and analytics and cloud intelligence. CDN vendors may cross over into other industries like security and WAN optimization.” (Wikipedia, retrieved Dec 8, 2017
Simple use of CDN
- The most frequent use in education is to distribute videos via services like YouTube or Vimeo.
- Many services, e.g. learning management systems also can make use of this technology