WorldDirector cloud and CDN: since 1995

WorldDirector is a cloud and Content Delivery Network technology believed to be the first of its kind

 

History

WorldDirector was designed in late 1994 at NEXUS International Broadcasting Association (NEXUS-IBA) non profit R&D labs in Milan, Italy, and since early 1995 deployed for streaming audio, ftp archives and web pages belonging to the Association's members simultaneously from servers located in Europe and USA. It has been also offered to commercial companies to support the association's activities in local and international broadcasting. The technology was released for commercial exploitation to Wornex International, a NEXUS-IBA start-up, in 2002, and since then also available as a fully managed solution.

Technology

Differently from other CDN developed after 1995, WorldDirector is a proprietary technology based on open source that was conceived to provide globally distributed and fully redundant content. Itrequires no content modification of web pages (i.e. no "akamization"), and offers no single point of failure. It was conceived to continue providing delivery of content under a disaster situation (like a catastrofic earthquake), when both DNS and network connectivity may remain interrupted or disrupted for any period of time. It was also designed to provide fast access to localized content in less developed countries where connectivity may be scarce, slow or congested.

WorldDirector is currently deployed under two main variants:

  1. WorldDirector active CDN: provides total replication and acceleration of content at each node. Each node is independent of the CDN logic and can survive multiple failures at any other node. No central authority, and no central point of failure exists to undermine the possibility of each node to continue providing access to edge content. Under active configuration any N-1 number of WorldDirector nodes can become unavailable (i.e for maintenance) or unreachable, while content still remain available and reachable from each of the servers that are still reachable. Under this configuration nodes (or servers) can be brought down for maintenance, and brought back on-line without any disruption to content delivery.
  2. WorldDirector passive CDN: like most CDN implementation only provides remote (edge) caching and acceleration from one or more origin servers. This configuration as most CDN implementation can fail to provide access to content if the network connection to the origin(s) servers is interrupted or the origin server(s) are down for maintenance.

Comparisons with other CDN Technologies

Most other CDN technologies are based on a re-director node placed at a well-connected Point Of Presence (POPs). The redirector must be always reachable and able to sustain any kind of failures or attacks in order for all CDN nodes to deliver content.

However, when problems happen at the redirector node or if the redirector is unreachable from the edge of the Internet due to routing issues, all the CDN network become totally or partially unreachable. As such the redirector acts as a single point of failure for the whole CDN.

Redirectors also add additional latency, especially for clients at the periphery of the Internet. The WorldDirector technology deployed in the active CDN mode for N nodes (N>=2) are independent from any redirector or any central authority and also independent from one another. As such they can survive network failures while continuing to provide service seamlessly until at least one node is reachable.

WorldDirector does not employs redirectors by design, but uses multiple (N>=1) globally redundant autonomous nodes. Another difference with other CDN is that WorldDirector does not usually employs hundreds or thousands of caching nodes, and as such is easier to administer and has a lower installation and maintenance cost compared to other CDNs.

Other features

Other features provided inherently or optionally by the WorldDirector technology are:

 

ICT results on the European Commission web site