Why enterprises build their own CDNs

There once was a time that building your own CDN would have been unthinkable - complicated, expensive and not worth the hassle, considering that there were a number of well-known commercial CDN providers available who could make it easy to distribute content reliably across the geographies a company wanted to reach. CDN vendors offer the full package: hardware, software, network and so on, meaning that, for a long time, for most companies, convenience trumped other considerations. 

The problem, though, is that this is a generic approach. A CDN provider sells its services to multiple customers across sectors and industries, and they share all the resources the CDN provider offers, such as storage, servers, hardware and network capacity. For some companies, this is not a major constraint, and big-name CDN providers deliver content reliably, making the question of whether to dig into the complexities of building one’s own CDN a non-question.

Complexity no more: Building your own CDN is easier than ever

We’ve reached a stage in the digital era where companies are seeing the limitations of relying exclusively on the commercial CDN model, and this has converged with advances in technology that make building a CDN for yourself transparent and easier than ever.

Defy limitations: Why go your own way?

Companies in the content delivery game - which, these days, is pretty much everyone - will recognize that ceding control of content delivery to a commercial CDN has some drawbacks. 

• Control over content: Performance and security rely a lot on what you can control. Commercial CDNs are, as stated, giving all their customers access to the same set of shared storage, servers, and network, meaning that you end up competing for resources. A third-party middleman being solely responsible for the content delivery process takes control out of your hands.

• Content delivery performance: Creating a hyper-local private cloud, reaching the more far-flung audience centers, increases the ability to deliver when commercial CDNs are overwhelmed. Highly dynamic content does not lend itself well to commercial CDN delivery: in a shared environment, it is hard to get caching right. With a private cloud, with its own caching engine, you can cache even dynamically generated content, providing not only faster throughput, but also local caches that can keep the service running in the event of a major origin server outage. Long-tail content also lends itself better to private cloud delivery, as the cost and effort to distribute and cache on the commercial CDN overwhelms the value returned. As long tail content should be delivered at the same level of performance as other elements of your service, creating a private cloud to serve it makes a lot of sense. 

• Security: Multi-tenant CDNs and shared networks from which content is delivered is not optimal for security reasons. A private CDN, on the other hand, can act as a WAF and provide protection against DDoS attacks and other malicious behaviors.Security goes very well with the aforementioned "content control" point, especially given the new GDPR regulation, which came into force in May 2018. Protecting valuable data from leaks or breaches is a must for all companies serious about their content delivery.

• Availability: CDNs tend to locate their points of presence (PoPs) in the same places (i.e. large cities in major countries); as a result, during high-traffic periods, they share the same peering relationships, which leads to damaging congestion.If a website suffers an outage, users will blame the service provider and not the network. A private CDN gives you more freedom to decide where to place your PoPs, based on where your audience is located and where your traffic is coming from to make your services more available and reliable.

• Scalability: Related to the point on availability - the flexibility a private CDN provides allows every sysadmin to strategically decide where to deploy PoPs and most importantly how to deploy them (either cloud instances or on-premise).

• Cost control: Commercial CDN vendors bill by bandwidth and number of requests per second. Clearly this means that the price for delivering content can quickly grow unpredictably under this model. A private CDN ensures that capital investment gets shared more broadly, and the overall cost to operate is reduced. Many customers find that they can achieve significant cost savings by offloading expensive CDN transit to less expensive internally managed cloud transit.

Is building a private CDN right for you?

A private CDN solution might not be right for every company, but it’s worth taking the points described into consideration when planning your content delivery. Content delivery grows consistently more important, operationally and strategically, and the private route (or a hybrid mix of a private and commercial solution) can offer control and flexibility that was unthinkable just a couple of years ago.