The road to infinity is
paved with fiber-optic cable —
and gigantic server farms.
Comcast has completed the
first phase of the “Project Infinity”
video-on-demand content-
distribution network for its
Washington, D.C., and Philadelphia
regions. The MSO claims
it has put the infrastructure in
place to serve a virtually unlimited
amount of VOD.
“We are focused on offering
an infinite amount of choice,”
said Mark Muehl, Comcast senior
vice president of product engineering.
With the initial upgrade, being
marketed under Comcast’s broader
Xfinity brand, the operator has
boosted on-demand capacity from
8,500 hours to about 70,000 hours.
In D.C. and Philly, Comcast had
added 9,000 new movie titles per
month, offering a total of 25,000
free and transactional titles.
That expansion is possible
thanks to what the MSO calls the
Comcast Content Distribution
Network, or CCDN. In this architecture,
popular content is cached
at the “edge,” while less-frequently
accessed titles are delivered as
MPEG-2 streams directly out of a
centralized library to subscribers
over Comcast’s fiber-optic backbone
network (see “Comcast Preps
for VOD ‘Infinity,’ ” March 30, 2009,
page 3). The CCDN means that libraries
do not need to be distributed
in their entirety to Comcast’s
100-plus distribution points, simplifying
management and reducing
storage costs.
Comcast has built out the Project
Infinity VOD system with vendors
including Cisco Systems,
Muehl said. The operator has developed
proprietary caching algorithms
to find the optimal balance
between storage at the edge versus
the core. “If you have 100 requests,
you want as small a percentage as
possible of those served from the
central library,” he said.
Today, the operator has two
central libraries in place serving
East Coast regions, and it is in
the process of adding two more
in other parts of the country. Ultimately,
those four centers will
connect those more than 100 “islands”
of local VOD servers, located
in Comcast headends and
facilities across the U.S.
“We want a cookie-cutter design,
so we get predictable performance,”
he said.
Citing “security reasons,” Muehl
declined to identify the locations
of the VOD centers. Previously,
two locations Comcast was considering
were West Chester, Pa.,
and Denver, sources have said.
Muehl also declined to provide
details on usage statistics,
such as the average number of
streams served centrally. He noted,
though, that subscribers access
literally everything in the
expanded VOD library at least
once per week.
Comcast CEO Brian Roberts
first described Project Infinity in
a keynote at the 2008 Consumer
Electronics Show. At the time,
he described a strategy in which
Comcast would provide not only
a massive amount of content via
VOD but also online.
Currently, the CCDN doesn’t
deliver content for Comcast’s “TV
Everywhere” service, Fancast
Xfinity, which lets cable-TV subscribers
watch about 1,500 movies
on the Web. The goal is to eventually
combine the infrastructure
that serves VOD and Internet video,
Muehl said.
“Over time, we see these
technologies coming together,”
he said.
In addition, CCDN could be
adapted for time-shifting services,
such as network-based digital
video recording. “We haven’t
announced network DVR plans,
but we could leverage the CCDN
to deliver that,” Muehl said.
