Feasibility Study of a Digital Platform for the delivery of UK ... - BFI

UK FILM COUNCIL
The Providing Machines
The two distinct models of client/server and peer to peer are discussed in more detail below. They both, however, rely on the same
general principle; namely that it is best to locate the machine which provides large data files such as media files as close as possible to
the end user.
With client/server networks, although it is technically possible to deliver media from a single server there are risks to the quality of the
user experience if the service is popular. It is most common that a cluster of servers acting in parallel to appear to be a single server is
used at the centre of the operation.
In addition to this, especially with larger media delivery projects, it is very common to use a content delivery network (CDN) such as that
provided by Akamai, Vitalstream, Entriq, and others. These networks generally operate by locating “mirror” servers containing the media
files around the edges of the network, i.e. as close to user’s machine as possible, in order to get the best possible speed of delivery of the
file and, thus, avoid buffering of streaming media or excessively long download times.
No media delivery project of scale should consider the operation of a client/server model which does not include the use of a CDN and
content mirroring in this way, even if there is also a single server or cluster at the heart of the operation. Even with a CDN, it is essential
to closely monitor quality of service and to ensure that the quantity of servers and the available bandwidth is sufficient to meet
anticipated user demand. Actual usage figures must be kept under review – particularly diurnal or seasonal peaks in usage which can
severely stretch under-resourced operations (even the BBC has problems from time to time).
The Consumer’s Bandwidth
The final variable, over which the provider usually has no control, is the bandwidth of the end consumer. Some services such as BT’s
proposed video on demand service and many walled-garden services (including current mobile offerings and traditional linear TV delivery)
do have a direct relationship to the consumer but more open offerings (such as those across the internet) do not.
It is extremely unsafe to rely on the data rates published by providers as a guide to the actual bandwidth available on the user’s
machine. This is affected by a number of factors including contention ratios (how many other people share your connection at the
telephone exchange) and other activities using the connection in the household (e.g. other users on a shared connection, virus software,
etc).
Feasibility Study for a Digital Platform for the delivery of Independent UK films and Specialised films to the Home
UK Film Council © 2006
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