When to separate DNS from CDN

If you sign in to a content delivery network (CDN) provider, you may see DNS as part of their standard service package. To access content provided by a CDN, the Internet needs to know where to send the traffic. A CDN makes it easy to configure and manage these DNS settings.

It’s easy to accept a DNS service as part of your CDN package. Most organizations just getting started with a CDN won’t give DNS a second thought. They just assume that the two services should go together naturally.

From a management perspective, it certainly makes sense to co-locate DNS within a content delivery service. The ability to configure and manage your DNS along with your other CDN settings can save you some time and effort. Who doesn’t want to save time and effort?

The problem is: DNS features that seem small can actually have a significant impact on how much you pay to deliver content, the quality of content you deliver, and the resilience of the content you deliver. Even the claims of ease of use have been turned on their head.

We’re a little biased here, but that’s because we believe the case for using a separate DNS service is overwhelming for many CDN users.

The bottom line is: If you currently use multiple CDNs or plan to use multiple CDNs in the future, you’ll want to avoid being locked into a single provider’s ecosystem and cost structure. To do this effectively, you’ll need separate DNS systems that work across providers, allowing you to choose the best option at any given moment.

Let’s look at some of the benefits of using an independent DNS provider, including:

• expense
• Performance
• Ease of Management

expense

DNS products that are bundled with CDN services do one thing that makes the CDN more robust: You can use DNS to steer traffic elsewhere, but it’s not exactly in your interest for a CDN to send you elsewhere. After all, a CDN only gets paid when it delivers your content.

Content delivery costs vary greatly depending on your ISP and region. The CDN does not use this data for traffic optimization. Because this affects your bottom line.

For individual queries, the cost difference may seem minimal, but when you multiply this by the number of queries worldwide and look at it over time, the total adds up quickly. The ability to use DNS to direct traffic to the cheapest CDN can ultimately result in significant cost savings.

Performance

Just as content delivery costs can fluctuate, there are significant differences in performance between CDNs. Below is a random sample of real user monitoring data from some of the leading content providers.

As you can see, the data is all over the place. At any given time, different CDNs may offer significantly better (or worse) performance.

If you’re using the default DNS that comes with your CDN, it’s very difficult to switch to a better performing CDN in real time. Doing so requires knowledge about which CDN is the best choice. and Ability to quickly configure DNS to coordinate traffic between providers. CDN providers do not provide this data.

resilience

Any CDN worth its salt has a 100% uptime SLA. Nonetheless, service outages are inevitable and occur more often than providers like to admit. (Monday.com has a great article about this.)

When such an outage occurs, your content will go offline unless you have an easy way to fail over to another service. The DNS bundled with CDN packages is designed to only direct traffic to one place, so you may not have many options if that one place goes dark.

An external DNS provider allows you to automatically switch from one CDN to another in the event of an outage, keeping your content online and monetized.

management

Remember when we said at the beginning that managing your DNS settings within your CDN platform will save you time and effort? That’s true but Only if you only use one CDN.

However, if you use multiple CDNs, DNS management can become a huge hassle. Moving traffic between providers requires going into each platform and reconfiguring them all manually. And let’s face it: no one wants to do that. A separate DNS configuration step usually means that only a breaking change triggers a move to where traffic goes. This is how CDN providers like it.

Benefits of a Separate DNS Layer

If you use multiple CDNs, separating your DNS layers will help you optimize to get the most out of each provider through the magic of traffic steering.

Do you want to optimize your costs? DNS providers, independent of CDNs, can analyze data in real time and automatically steer traffic to the cheapest option at any given moment.

Want to optimize performance? Analysis of region, ISP, device, and other factors feeds into automated DNS logic to direct users to the best CDN available.

Want to keep your content online despite periodic service outages? A dedicated DNS provider can automatically failover to the CDN you are currently running, providing seamless content transfer between providers.

Want to save time managing DNS? Having a single, fully automated DNS control plane across your CDN gives you the ability to make the changes you need without the hassle of manual configuration.

Needless to say, the NS1 is designed to do all this and more. By leveraging the power of DNS, we can deliver the lowest cost, highest performance, most resilient and easy-to-manage operations for some of the largest and most important content platforms. Our advanced traffic coordination options make it all possible.

Learn more about optimizing application traffic with IBM NS1 Connect®