End-users have increasingly high
expectations concerning the quality of service (QoS) they experience, and
content providers have to find the best solutions to meet these evolving
needs. Dynamic CDN selection is one of them.
The benefits of
a multi-CDN approach
Employing a multi-CDN approach is highly beneficial for
OTT multiscreen delivery compared with relying on a single CDN. There are
several reasons for this. Oftentimes, the best CDN for delivering video
content in one country may not be the same for another region in the
world. Additionally, some CDNs perform better with certain subscribers,
and some are more expensive than others but provide a better quality of
service, which is critical for delivering premium
content. Enabling operators and content providers to balance
traffic between multiple CDNs ultimately makes sense from both a QoE
and cost standpoint.
A CDN selector
to manage static and dynamic criteria
With a CDN selector, the content owner or pay-TV operator
can define a wide range of static criteria according to which CDNs can be
- the end-user’s geo location
- the type of content
- the time of the day
- the end-user’s Internet Service Provider (ISP)
Operators can create rules based on these criteria to meet
specific needs; the optimal choice of CDN will vary in accordance with
them. The rules can be applied to all the CDNs at the same time, avoiding
the need to create them independently for every single CDN.
But an approach based only on static criteria does not
address the fact that the quality of the service delivered by a CDN can
greatly vary in time. A QoS criteria
must also be taken into account dynamically to optimize the video
of a dynamic approach
The QoS perceived by an end-user can vary very rapidly as
it is determined by constantly evolving factors related to the CDN and
the state of its servers. During peak times, during maintenance periods,
or when a link is down, the delivery is affected.
When the CDN selection is based on a QoS criteria, the
feedback from the CDN must hence be taken into account instantaneously by
the application and not rely on information that is older than a minute.
The information must also be closely related to the
context of the end-user, its location, the streaming format he is using,
etc. and not be based on an average and mutualized feedback that will not
take its specificities into account.
The evaluation of the different CDN must not generate a
traffic overhead that will increase the cost of the solution by
increasing the volume of content to transit on the various CDNs.
The CDN response time is a key information for assessing
the quality of a CDN, the CDN selector must therefore take this parameter
into account dynamically together with the bitrate that it is able to
Broadpeak's umbrellaCDN solution
CDN selector can manage both static and dynamic approaches,
enabling operators to deliver the best QoS
to their end-users. This solution integrates Broadpeak’s CDN
Diversity technology, a powerful tool to improve the QoS
as it dynamically takes into account the quality of several CDNs in real-time,
and requests more from the best performing ones.
The real-time speed of the selected CDNs is monitored,
which enables the system to adapt itself to changing network conditions.
CDN Diversity privileges the CDNs with the best performances without
inducing any overhead, since all the data that is received is used by the
This dynamic management improves the end-user
experience as it improves the startup time, delivers the higher
bitrate layer and strongly limits quality variations.
To find more about Broadpeak’s umbrellaCDN and CDN
Diversity, you can download the whitepaper “umbrellaCDN™: CDN selector
for live and on-demand content” here.