Content delivery networks (or CDNs) offer a reliable content distribution system for websites and online video platforms across the world. These systems work to speed up content delivery, such as web pages, videos, games, and even software updates to web users based on their geographic location and performance. There are different types of CDN options, and each offers its own unique solution for IT professionals:
With a single pure-play CDN, you have a single provider using their own network and hardware. These were traditionally designed as hardware-based, with PoPs deployed in geographical locations based on the provider’s preference, often based upon the most economical option and thus, not necessarily the best performing option. Although the single CDNs are marketed and perceived as such, no single CDN provider could give you the best performance everywhere in the world at every point in time. The main benefits of such a solution, in addition to speed (in the specific location where the Point-of Presence are located) are offload from the origin server, security and high availability. Those benefits are highly significant and that’s why this market has been growing continuously for the last twenty years.
By contrast, multi-CDN solutions are viewed as an overlay of existing, individual CDNs, as they are a combination of various PoPs from different CDN providers. This solution typically offers more PoPs spanning a much larger geographical area. Therefore, multi-CDN delivery offers optimal performance and virtually infinite scale, all across the globe. Traffic routing and distribution can be configured based on performance, availability, pricing or other factors depending on each customer scenario.
Then there are private CDNs and hybrid CDNs. Private content delivery networks are specifically tailored to meet individual companies’ needs. They allow you to set up dedicated presence in customer locations, can run on commodity off-the-shelf hardware or can even be virtualized or containerized. Unlike single and multi-CDNs, private CDNs do not share resources with other customers. Instead, they utilize dedicated and optimized connectivity and architecture selected by the customer. Typical use-cases for private CDN are companies with extremely heavy bandwidth and throughput needs (i.e. broadcasters, content publishers), companies with in-house network capacity (i.e. telco OTT platforms) and companies with rigid security and compliance requirements (i.e. payment or government related).
Hybrid content delivery networks are composed of a combination of different types of CDNs. Our case, in particular, is a hybrid composed of multi and private CDNs. Hybrid networks such as this allow users to optimally balance content delivery throughput and bandwidth needs as determined by the desired reach, performance and price.
Pros and Cons of Private CDNs vs. Multi-CDNs
The benefits of selecting either of these approaches are driven by the traffic characteristics, feature requirements and expected traffic growth.
Multi-CDNs offer optimal reach and redundancy, which are essential when you want to reach an international or worldwide audience; or when the amount of needed CDN capacity is unpredictable and/or irregular.
Private CDNs are generally used in high-demand environments given their dedicated and tailored approach. They allow providers to use their own commodity hardware (or virtual platform) and perform scaling techniques easily in any location where a point of presence is deployed. Private CDNs are typically chosen by companies with very high amounts of traffic or when dealing with very specific requirements. Examples of content publishers and content owners utilizing private CDNs are Valve, Spotify, Netflix, Twitter, Sky, BBC and RTL. Another typical use-case for Private CDN are ISPs with an OTT offering like for example KPN, LibertyGlobal, ComCast and POST. ISPs utilize Private CDNs to offload traffic from their backbone networks and to keep the content within their network in the most efficient way possible.
In comparison with private and single CDNs, multi CDNs are the optimal choice for reach, redundancy and elastic scaling at a low-cost barrier to entry. A potential downside is that you would have to share resources and capacity with other customers on the platform and the available configuration options are more limited, as the features available are limited by the common denominators between the various CDNs.
Advantages of Choosing Hybrid CDNs
For companies considering deploying their own content delivery network, a hybrid CDN would potentially offer the ideal combination of dedicated resources, cost-effective traffic offloading, scale, and reach.
To take a real-world example, imagine a situation where a local broadcasting company offers online video streams in their home country. Their national and local traffic patterns are predictable and the broadcaster would have enough demand to justify building a tailored and dedicated private CDN within the country. However, the broadcaster also wants to give users outside of the country an optimal experience, which will require a more geographically dispersed approach. Next to that, the broadcaster also has various unpredictable live events (a sports match, for example) for which the amount of viewers is unknown. The broadcaster does not want to deploy and pay for the needed equipment and connectivity to handle the spikes for these events as they normally only last a few hours, while the rest of the time the infrastructure sit mostly idle. This is where a hybrid CDN approach comes in – the majority of the national traffic is handled by the company’s private CDN deployment, but it has the ability to offload overflow traffic to the Multi-CDN to achieve global reach and near-infinite local scale. This way both its global users and live events are delivered optimally in any given scenario.
Having a hybrid CDN ensures the content is always available, anywhere in the world at the best possible performance. The built-in redundancy and resilience of a multi-CDN ensures another CDN will take over in case of a CDN failure in any location. With only a single CDN, geographical coverage is more limited but the configuration and personalization of the features needed is far reaching.
The Bottom Line
Utilizing a multi-CDN or hybrid CDN setup will provide better control, increase the performance of your content delivery and will improve customer perception, wherever in the world your users reside.
Not only will you be able to direct traffic to your own private CDN or PoPs that are part of the multi CDN, but you will also be able to maximize performance and efficiency where necessary. The scalability of the combined multi-CDN and private CDN allows you to meet performance and capacity needs for any content, whenever it is needed. This type of flexibility gives you the ability to scale cost-effectively and meet the ever-increasing demands of content delivery.
MartyJanuary 20, 2019 at 10:27
This is pretty good information. I look forward to learning more about cdn and how to apply it to benefit my own needs