in correlated downtime. Hence, combining a CDN origin
platform and third-party CDNs will help distributing the
risk of downtime by allocating the traffic towards the
working CDN if the other is down.
• Performance Improvements
Using hybrid CDN creates better use of hardware, better
cache management and better network management. By
creating a platform leveraging both origin CDN and cloud
CDNs, the Origin CDN platform can be targeted on areas
where the customer has most of its users. Thus much
better performance is achieved.
Integrating a smart, performance-based load balancing
platform like Cedexis with this setup will ensure competition
between all CDNs in the mix to achieve the best possible
performance for each user.
• Better Cost Control
CDNs tend to provide better pricing to customers with
strong origin platforms. On top of that, delivering most
of the content to targeted areas with private CDN nodes
ensures much better cost control and performance.
However, the challenge is that most companies do not
have the expertise for the DI Y approach and most of the
time it is not feasible to invest in this know-how.
A hybrid CDN provider can help the customer set
up a “managed” private CDN platform and help the
customer integrate these private CDN nodes to cloud
CDNs, to build a strong hybrid CDN Solution.
• Better Security
A company’s control over the system is increased with
hybrid CDN when compared to legacy CDNs. This increase
in control also means security enhancement. For many
web application owners, usage of cloud CDN is not an
option due to the content sensitivity. In this case, keeping
the mission critical contents with the private CDN part
and keeping the others in cloud CDN creates flexibility in
time and costs whereas ensuring the security.
HOW DOES A CDN WORK?
A CDN infrastructure for streaming and video services
consists of a net work of encoding/transcoding servers,
application servers, load balancing algorithms, mid-tier
WHY MIGHT A HYBRID CDN BE NEEDED?
cache servers, and edge/delivery servers. Encoder/transcoder
servers are by default the closest servers to the source, and
they work to receive the media from the media source and
optimize it for each device and player. Application servers
work to optimize and distribute data inside the net work.
And the mid-cache and edge servers transfer that media to
the end-users. The edge servers need to be located closest to
end users to gain better user experience. On top of that, load
balancing servers—the servers that are used to balance the
server loads bet ween the servers based on performance and
service uptime—are also needed for added performance
optimization. When an end user wants to watch the streamed
video, either live or on-demand, a DNS-based routing to the
closest and best performing edge server starts to operate and
the media requests are transferred from that server.
The strongest drawback of building a DIY CDN or
private CDN is the cost of the investment and the required
know-how. Server costs, network costs, maintenance,
upgrades, and support all add up to major investment costs.
These costs, lack of know-how, and risk of losing business
focus create the main reason for many OTT companies
to move towards cloud CDNs or combine those two and
have a strong hybrid CDN. In order to use cloud CDN, an
agreement with a third-party CDN provider is necessary.
Through this agreement, the corporation outsources a great
deal of its operational cost while also encountering some
visibility and control limitations. In this model, most of the
cost including maintenance, upgrading, support, servers,
and system management are paid by the third-party CDN
provider and the corporation avoids the capital expense,
time demands, and stress of these factors. The financial
burden of those shifts into a service with a monthly fee that
is often based on utilization and volume of the data.
Another reason to use hybrid CDN is due to lower
CDN performances in different geographic locations. For
instance; in some markets; some global CDNs have very low
cache capacity due to older equipment in that area. Media
is arriving from a high distance to end-user, with strong
latency and buffering issues. Especially for subscription-based OTT companies, buffering and latency create another
business issue, customer churn because of low quality
service. Because of this, OT T players should strongly
consider creating a hybrid CDN by building private CDN
infrastructure in those areas and by using cloud CDN in
locations where cloud CDNs perform well. By using a hybrid
CDN infrastructure, these companies are able to make
performance based routing according to their requirements.