BT plans launch of content delivery network for UK internet
Sian Baldwin: hundreds of content caches across
country, integrated into ISPs' networks
BT is planning to launch a UK-wide content delivery network
that will offer owners of video and other content high-quality
access to internet service providers and on to their end
The UK incumbent is building the new network because of
increasing customer demand for high-bandwidth video content -
and a realisation that high-definition TV and movies will put
an even greater strain on the existing internet services in the
next few years.
"We're planning to launch the new network in May," says Sian
Baldwin, BT Wholesale's director of broadband and content
services. The UK incumbent has already built a number of caches
to store video content and deliver it into the network on
behalf of content owners.
The company then plans to launch a video streaming variant
of the service in March 2011, providing broadcast channels and
other live content to ISPs.
BT Wholesale is making the investment - though Baldwin would
not put a figure on the sums the company is spending on the CDN
- in the light of increasing capacity in the local loop thanks
to high-speed DSL services and the arrival of
"IP traffic will quadruple between 2008 and 2012," says
Baldwin - that's a doubling every two years, similar to Moore's
law for microelectronics.
In 2012 traffic in the UK will be equivalent to a continuous
120 kilobits a second spread throughout the 24 hours of each
day, she adds. "That's how we measure it." In 2008 it was 30
kilobits a second. "And it's almost entirely video."
In the UK, the BBC - the national broadcaster - provides
online access to most of its TV and radio programmes for seven
days or more after first transmission, in high quality video
and audio. This service, called iPlayer, is so popular that it
is consuming 12 gigabytes of data every second.
This service is likely to be succeeded later in 2010 by an
even more ambitious online TV project, Canvas, which will be a
cooperative venture of four broadcasters - the BBC, Channel 4,
Channel 5 and ITV - and two telecoms operators, BT and
"We are fast approaching what we call the 'grumpiness
triangle'," says a BT spokesman. "ISPs are grumpy because the
growth in video increases their backhaul costs and so they
traffic shape. This makes end users grumpy because they don't
want to wait to watch their favourite television programme.
And, in turn, this makes the content creators grumpy because
viewers can't enjoy their programmes as they intended."
The problem for network providers and ISPs is that current
networks were designed for email and web surfing, not for
continuous video, and users' habits have changed. For every one
minute of surfing people consume 30 minutes of online
"We're planning ahead of the launch of Canvas," says
Baldwin. "The CDN service will be tightly integrated into our
At the moment ISPs "are cut out of the process", she adds.
With the CDN in place - using caches close to the ISPs'
networks - they will be "about to make quality guarantees to
BT Wholesale is hoping that ISPs will not be tempted to
build their own CDNs - warning that they will then need to
arrange interconnection with all the broadcasters and the
content aggregators. "We can provide a single point of entry,"
This will fill a gap she believes exists between the
companies that specialise in transporting content
internationally - mainly Akamai Technologies, CDNetworks and
Limelight Networks - and the ISPs' and local-loop unbundlers'
networks that reach the consumers.
"Once the content is in the UK, what happens to it?" asks
Baldwin. "I see that localisation of content delivery is the
BT Wholesale already has four content caches in operation as
part of its pre-launch trial - one in the division's
headquarters in Faraday House, central London. "We'll have
hundreds by the time we're finished. It's part of our capacity
The company hopes to launch the service with three variants
that ISPs will be able to select: a basic service, which brings
content to the edge of the network; a "best efforts" service,
with caches integrated into the network, "but no quality of
service guarantee", she says; and "an assured service, where
we'll deploy caches deep within the network".
The caches are actually in the same place
for both products, but best efforts has no video QoS, she
adds, and so the retailer would need to prioritise the
traffic instead of BT Wholesale doing it for them as a complete
service. What will BT Wholesale charge ISPs for the
service? She won't say.
Though Baldwin is planning for a launch in May, the real
test will come in December 2010 - when viewing peaks for the
Christmas and New Year holidays. "Christmas will be critical,"
"This is the biggest growth market in the industry," she
says. "There's a huge explosive market for content. It would be
just crazy to ignore it." GTB