Why a dynamic and real-time approach is the best option for CDN selection?
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 chosen:
- 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 delivery.
The importance 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 reach.
Broadpeak’s umbrellaCDN solution
Broadpeak’s umbrellaCDN 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 player.
This dynamic management improves the end-user experience as it improves the startup time, delivers the higher bitrate layer and strongly limits quality variations.