About the Trial | Background to the Trial | Archive Material
Reports on the findings of the JANET CDI Trial phase 1 and phase 2 are now available.
The JANET CDI trial was set up to define architectures for Content Delivery on JANET. It comprised six HE and FE sites and assessed a range of differing content delivery techniques and technologies over a range of network connection speeds.
The sites involved in the trial were:
The JANET CDI Trial delivered content using a number of manufacturers' solutions for the management and networked delivery of MAAS/BUFVC (Managing Agent and Advisory Service/British Universities Film and Video Council) moving image and sound collections for the education and research community.
The diversity of material stored and distributed over the Internet has reached the stage where the original framework for guaranteeing peer-to-peer communication in the event of a catastrophe has become seriously challenged. The web allowed the self-publishing of magazine style material with images and other resources, and many speculated that the Internet would grind to a halt due to the proliferation of image intensive websites. Instead, best practice for web publishing, and techniques to speed the delivery of these websites to the end user (such as co-locating Web Servers in network backbones and caching closer to the end user) have been developed.
More recently, the delivery of moving image and sound content over IP networks (streaming) has become much more commonplace, as CDNs (Content Delivery Networks) have emerged which take content off the congested Internet and deliver it to the end user from a closer location (edge) than the source. They can reduce network related factors that cause unsatisfactory streaming. These factors include:
All of these can cause buffering in the media player at best, and a dropped connection at worst. A CDN will normally bypass the unpredictable Internet by providing an overlay network, either terrestrial (via fibre) or over satellite. Some even use QoS (Quality of Service) mechanisms to offer SLAs (Service Level Agreements) for the guaranteed delivery of moving image and sound content.
During the Internet boom of the late 90s several commercial CDNs were created, but after the boom ended many were bought out or closed down. The issue of return on investment for streaming content is inherent in the nature of streaming from a unicast server: the more popular a media file, the less available and more expensive it is to deliver.
The eCDN (enterprise Content Delivery Network) is a recent phenomenon, describing a medium to large company with its own network infrastructure that takes steps to improve content delivery by adding caching, load balancing, redirecting and other technologies to improve the delivery of content within the enterprise. This can also include the use of multicast and other networking protocols, and the purchase of additional content routing/switching technology.
JANET is a network that could be described as falling between the Internet and enterprise model. JANET(UK) is able to exercise a certain amount of control in the IP layer, and has the option to architect a CDI (Content Delivery Infrastructure) that can ensure the efficient delivery of both internally ingested content and external content from the public Internet.
The call for participation and application form are available
