3 challenges CDNs face (and 3 solutions to optimize them)

CDNs are great for reducing the distance between where content originates and where it is viewed. Up till now, the basic rule has been that the closer content is to users, the better it is for your business. However, these new developments bring new challenges and CDNs must be optimized to deal with them. 

A single page on a social media platform can already seek to resolve hundreds of requests to enable a fluid user experience. The rapidly growing number of requests is unlikely to be slowing down any time soon. This can make things exceptionally difficult for CDNs, which will hit the speed of your content delivery which, in turn, will probably hit your bottom line. The speed of content delivery can be the difference between a sale or not: one study by Amazon showed that 100ms delay in page load time can lead to a 1% decrease in revenue. 


As immersive services that offer interactivity and adaptability increase thanks to the spread of 5G and edge technologies, previously acceptable rates of latency become unacceptable. If you are working in VOIP, video streaming or online gaming, your CDN needs to be able to handle dynamic content - content which is continuously changing, as opposed to static content such as still images - where every request must be forwarded to the origin server to allow your product to be entirely responsive to and tailored for each individual user. 

A standard CDN won’t be able to improve speeds for this type of content as many of these actions cannot be cached. Online gamers, for example, need to see their individual gameplay play out on every participants’ screen within a matter of milliseconds. Ads that pop up on a webpage as a purchase is being made and that are tailored to the buyer must also be selected in milliseconds. The same applies for video streaming and VOIP. Platforms like Twitch combine various dynamic features at once.


If your product is currently or will be latency sensitive in the future, ensure that systems are put in place to meet its current or future needs now. The same applies for whether your product will need to be edge compatible. Ask yourself: will my product need to become more dynamic? The systems you are building now must be able to grow as fast as the products they will be competing with that are coming over the horizon as we speak. 

Flash crowds

Another area where CDNs must improve - and that is growing rapidly - is live event streaming, replete with interactive features and multi-screen delivery. Live events have been stand out performers in the ever more competitive battle for audience engagement. CDNs provide scalability but they must be optimized to keep that audience engaged. 

One of the biggest challenges live streaming faces is the flash crowd - a sudden boost in viewer numbers during a stream. Live stream viewer numbers are volatile and many audience members will jump on the stream at the same time to see a key moment.

During the NBA finals game six, for example, viewership went from close to zero to 2.04 million in the third quarter, with 100,000 new viewers joining per minute at various times. This explosion of scale pushes CDN to its limits. Furthermore, any disruption to that live stream may cause interruption in playback. 

It’s crucial that a CDN can interact with both origin servers and clients during these spikes in live streams. As in gaming, the encoder must constantly publish new media and the CDN must fetch and propagate that data. It’s impossible to avoid some latency but to keep that to a minimum, you must ensure your CDN minimizes the load on the origin server and simultaneously keep the entire network as free as possible to enable a smooth viewing experience.

Regional management 

Not all CDNs are created equal. Content providers must ensure they are using the right CDN for the job. Regional considerations can play a major role in the performance of CDNs, what works in the US may run into difficulties in China or the Middle East. If your CDN runs into a problem, the best option is often switching to another. Creating a system that is capable of hopping between CDNs remains expensive and complex but, as the load grows heavier, the need for the capacity to use multiple CDN only grows with it. 

What you can do now to optimize your CDN

Backbone and Last Mile

DNS challenges are a common stumbling block for CDNs, when they are deployed, a company’s DNS is relegated to their DNS provider which is then relegated to the CDN. There are plenty of examples of this chain breaking down which then leads to errors. A CDN therefore must be monitored regularly. Many cloud-based systems are not yet sophisticated enough to monitor all fronts by themselves. Therefore, a company must be committed to last mile and backbone monitoring. This type of monitoring will also ensure that any flaws in how users are mapped to the most appropriate edge server are spotted before user experience is significantly affected.


Mapping systems face a whole number of challenges that are in constant flux. While organizations do not typically have access to their CDN provider’s routing, mapping issues can be detected and highlighted to a provider. Wide ranging analysis from numerous points is necessary in order to evaluate what end users are actually seeing. If download times are significantly different in different regions, this may indicate a CDN’s mapping is malfunctioning. If you are able to compare the experience of end users in different regions, you can fix the error efficiently and effectively.  

Front End

It’s easy to think your CDN can do all the heavy lifting but your front end design still has a direct effect on the speed of delivery. A CDN does not change the fact that the more bloated a website, the longer it’ll take to load. 

A well put together application being delivered by a CDN will lead to vastly improved results. While your CDN carries the content, front-end optimizations means that content is helpfully packaged so that content can be delivered with speed by the CDN. Optimization can include file compression, removal of unnecessary characters in coding, automatic device based image transformation, pre-fetching and reduction of unnecessary requests. 

There are CDN providers like System 73 that provide this optimization but with optimization comes more complexity and greater complexity means companies must be even more conscious of how they monitor their backbone. 

Considering how important - and expensive - CDNs can be, these are fairly simple steps to ensure they are delivering on what they promise. Furthermore, these solutions are likely to remain relevant for many years to come as delivery systems grow and develop.