What Is a CDN (Content Delivery Network)?
Content Delivery Networks (CDNs) are systems of distributed servers, which are intended to speed up website loading times and protect against issues caused by traffic spikes.
CDNs store copies of static content throughout their networks, and then serve them up to users from the most geographically-logical server locations. Since they typically have servers all over the world, loading times can be sharply reduced.
How Does a CDN Work?
As mentioned above, CDNs enable webmasters to lower their sites’ load times by tapping into a network of servers, each of which serves the visitors that are geographically closest to it. CDNs also give webmasters the added benefit of peace of mind, as they enable websites to deal with spikes in traffic more effectively.
CDNs rely on data centers distributed in key locations around the world. If you’ve configured your site to work with a CDN, it will store copies of your static content on its servers (this is known as ‘caching’). Each time a user attempts to access your website, the service will automatically send them this cached content from the server closest to them.
The fact that your content is loaded from multiple servers limits the potential for system crashes when your site receives an unusually high level of traffic. Whether one of your articles goes viral or you experience a Distributed Denial of Service (DDoS) attack, CDNs can help keep your site available to the public.
What Are Points of Presence (POPs)?
When it comes to understanding CDNs, one key term to know is ‘Point of Presence (POP)’. This is a physical access point where two or more networks come together and share a connection.
POPs are important for determining how quickly information can travel on the internet. The devices that make up these POPs are typically switches, routers, and servers. This infrastructure element is what enables remote users to connect to the internet.
What Are Edge Servers?
Edge servers are another vital element, and are part of a larger concept called edge computing. This is an approach to network technology that moves data exchange points from busier central locations out to the edge of the network, and closer to individual endpoints. These endpoints can be personal computers, laptops, mobiles, and other user devices.
Edge servers are made up of multiple pieces of advanced technology, while a POP is likely to be a single server in a simple environment. Edge servers are part of high-tech network infrastructures, and are typically located near Internet Exchange Points (IXPs). By comparison, they tend to be more sparsely located than POPs.
One of the benefits of using edge technology, especially in terms of CDNs, is that it can greatly increase network security. This is made possible by enabling the use of protective methods closer to your actual endpoints. You can think of this as securing each individual room in a house right at the door, rather than down the hall or out on the lawn.
What’s the Difference Between a CDN and a Web Host?
There are several key differences between a CDN and a web host that are important to understand. One of the essential distinctions is that a traditional web host is usually a single server that hosts your website and its contents. This server delivers all of your content to users when they access your site through a web browser.
A CDN, on the other hand, is made up of a network of servers that are dispersed across the globe, and deliver both your static and dynamic content to users. This is done through the server that is physically closest to each user, meaning that the content often arrives much more quickly.
Benefits of a CDN
The key benefits of a CDN can be summarized as:
Let’s explore each of these advantages in more detail.
Distance is one of the main issues that causes slow websites – the further away the user is from the site’s server, the longer it will take for a request to be fulfilled. Often, this will result in an extra second or two of loading time.
This matters because speed is important when it comes to providing a high-quality user experience, as well as for Search Engine Optimization (SEO). Using a CDN can decrease your site’s average loading times by cutting down the distance between users and servers. It’s worth noting that some users may see more marked improvements than others, depending on the location of your original server and their own internet connections.
Major spikes in traffic can cause unprepared websites to crash and become unavailable to users. Depending on your web hosting provider and which plan you’re using, your site might not be ready for a sharp uptick in visitors either.
A CDN enables you to mitigate this risk by spreading the burden over multiple servers. If one server can’t deliver the content, another one will, and your website should stay up and running.
Using a CDN will enable you to scale your site more efficiently, as you’ll be able to deal with higher volumes of traffic. You can also save on hosting costs, as you won’t need to upgrade to a more expensive plan if you only experience an occasional spike in traffic.
Most reputable CDNs provide you with in-depth analytics regarding your visitors. Some charge you depending on how many resources you use, so it makes sense for them to keep track of this information.
Regardless of the reasons for collecting it, the more data you have about your visitors, the better. This enables you to make more effective improvements to your website.
Implementing a CDN can also add a layer of security to your WordPress website. We mentioned earlier how CDNs can help prevent DDoS attacks, by handling the harmful requests that come in and preventing them from getting to your database.
Additionally, some CDNs offer two-factor authentication and additional firewall protection. Bot filtering is another option to consider if you’re looking at CDNs specifically for security reasons.
URL Structure and CDNs for SEO
Since CDNs serve user-stored copies of your static content, their URLs won’t look normal. For example, a typical image URL path could look something like this:
After implementing a CDN, the page will load the image from an address.
That URL indicates that your assets are now being loaded from a third-party server. You’ll enjoy all the benefits we discussed earlier, but you may run into indexing issues.
To fix this problem, you can set up a custom subdomain such as cdn.yourdomain.com, and create a CNAME record using a DNS zone editor tool (which is available in most web hosts’ cPanels) to point it towards your CDN’s URL. This isn’t necessary, but it can be helpful if you like to optimize static content – such as your images – for SEO.
CDN Services for Your WordPress Site
CDNs work with most website platforms, and WordPress is no exception. Enabling one can be relatively straightforward, especially if your host does the heavy lifting for you (as we do!). Moreover, any efforts required to enable a CDN are well-justified by the improved speeds and reliability your WordPress site will enjoy.
Fortunately, the CDN market is pretty vibrant at the moment. We’ve researched four of the best options and included their key details below, so you can get a better idea of what they each have to offer.
StackPath (Formerly MaxCDN)
If you’re new to CDNs, StackPath offers an easy-to-configure option that’s great for beginners. One factor to keep in mind, however, is that StackPath’s network seems to focus on more western (US and Europe) locations, with fewer servers throughout Asia, Australia, and South America.
When it comes to WordPress, StackPath offers two different approaches to setting up your site with the CDN. You can integrate with just your static assets, or go big and do a full website integration.
Just a few of this particular CDN’s benefits include simple pricing options and easy setup. You can try the basic, $10 per month service for free for one month without providing payment details. Additionally, you’ll have access to 24/7 tech support, and the ability to bundle or ‘stack’ services so that you’re only paying for what you need.
Cloudflare has one of the most extensive global networks, covering 90 countries, so it can route website traffic through the fastest path available. It also uses the Argo Smart Routing system to intelligently detect congestion and choose the best route.
One of the biggest selling points of Cloudflare is that it offers a free plan in its pricing tiers. Free plans come with the use of the global CDN, mitigation of DDoS attacks, and shared SSL certificates.
Paid plans start at $20 per month, and have a lot more added security features. However, if you’re not sure about CDNs, the free plan is one way to get a real sense for how this platform works without financial risk. Additionally, you can easily set up Cloudflare with your WordPress site by using the dedicated plugin.
KeyCDN has a pretty even balance of servers in Europe and the US, with just a few locations throughout Asia and South America. While it’s not as robust as other CDNs in terms of data locations, KeyCDN now offers specialized image processing as a unique feature. This means you can use its network to deliver optimized and resized images in real time, without creating multiple versions of your files to serve different devices.
KeyCDN does have some unique features that enable you to both pull content from your origin server, and push updated files to KeyCDN via File Transfer Protocol (FTP) applications. This means you can synchronize content on demand. KeyCDN offers a 30-day free trial, although it does not include tech support. Pricing is also a little more complicated than with some other CDNs, as your costs are determined by region.
When it comes to integration with WordPress, there are three official KeyCDN plugins to choose from. One plugin is dedicated to the image optimization features, and has a price range from free to $149. The other two plugins are free, and can help you set up your site with KeyCDN quickly.
Imperva (Formerly Incapsula)
Imperva is a CDN that uses a proprietary form of machine learning to create an intelligent caching feature. This means Imperva will make sure that the pages you change most frequently will always be up-to-date on the network.
You can stack and combine security features, application delivery, and more with this platform’s plan options. Using Imperva with your WordPress website takes a bit more work than with other CDNs, however. You’ll need to understand its rules functions in order to connect the two.
Imperva has 44 DDoS-resilient data centers globally, with a focus in Europe and North America. It also has more of a presence in Asia than the other CDNs on our list. In addition, Imperva offers two FlexProtect plans with an extensive list of services and features. All pricing is provided on a quoted basis, which means you’ll have to contact the company for accurate costs.
How to Set Up a CDN
When it comes to CDNs, here at WP Engine we keep things simple. Any customer can log into their User Portal and enable the service with just a few clicks. Afterwards, the integration process may take up to ten minutes to complete. It’s that simple!
Other web hosts also support the integration of a CDN, but you will often have to enable it manually. This may involve creating an account with your CDN, configuring it to cache your server’s static files, and making sure all your WordPress posts point towards the service (either manually or with a plugin). This is certainly doable, but it might take you some time, whereas we take care of everything for you.
Get Access to a Global CDN With WP Engine
At WP Engine, we offer CDN services with all of our plans. Premium and Enterprise users get up to 1TB of data for CDN usage included right out of the box. Startup, Growth, and Scale plans have CDN services included as well.
As far as we’re concerned, CDNs are a no-brainer if you’re interested in faster load times, increased reliability, and seamless scalability. Set yours up today with our managed WordPress hosting options!