A Beginner's Guide to Content Delivery Networks (CDNs)

A content delivery network (CDN) is an integral part of website building and management. Here’s what it entails and how best to use one.

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If you’ve ever loaded a website’s picture on your desktop or powered up an app on your phone, congratulations! You’ve probably interacted with a Content Delivery Network (CDN) since that site or app was more than likely using a CDN to deliver that content to you.

A CDN comes into play big time for website owners when managing content and overall website security, and it acts as an integral cog in the safe and effective media and data delivery system.


Overview: What is a content delivery network (CDN)?

A CDN, also called a Content Delivery Network or occasionally a Content Distribution Network, is essentially a globally interconnected network of servers (specifically CDN servers) that facilitate high speed, security, and increased access to websites distributing content and delivering it to end users.

Each CDN server holds what is really a cached copy of all your files and content media needed to be displayed on your site. CDN hosting uses geographical proximity to make channel decisions on distributing cached web content files and pages to end users.

When using a CDN service, your website’s content digitally lives on several servers across the globe. This makes it easier to distribute content to users as they visit your site, according to their geographical location. Each visitor receives requested content from the server closest to them, making the process faster.

This differs from a typical web hosting environment since all the traffic coming to your website gets sent right to your site’s singular host server holding all of its data. This often leads to lag times and general slowness because there’s no dividing of traffic into more manageable location-based chunks, particularly during surge periods.


How does a CDN work?

It’s all about efficiency with a CDN since it stores cached versions (multiple stored copies of the same content on different servers) of your site’s content in multiple locations, known as points of presence (PoPs). Each PoP holds several caching services responsible for delivering cached content to visitors within their geographic proximity.

Basically, a CDN works as an extended hosting service, putting your content in multiple places at once. Visitors have a faster and more seamless experience without hosting signals having to ping across great distances worldwide.

Because of this, CDNs are composed of huge networks of servers working to deliver digital data to users all over the world. These servers live in a large number of data centers and are connecting to one another first and then out to the internet.


4 benefits of using a CDN

A CDN can be your website’s best friend, and there are pretty compelling upsides to its usage.

1. Speed bump

One of the biggest and most obvious benefits is a dramatic increase in website speed for visitors, regardless of where they’re located. Since using a CDN means you’re distributing access proximity (through what are aptly named “proxy servers”), those various locations mean less traffic and less data congestion, which automatically increases loading and usage speeds.

2. Cheaper web hosting

Web hosting can quickly rack up bills, and a CDN can actually help rescue some of those costs.

Because CDNs take away users having to load static content from one single service point, that automatically frees up a ton of bandwidth and network resources, which translates to fewer operating and usage costs on your end for your hosting platform.

3. Tighter security

CDNs do a lot for site security, too. Because the internet is full of spam, bots, hackers, malware, and more, a CDN works as a sort of second barrier since malicious traffic will be directed to your CDN first rather than to your primary host.

The CDN thus blocks attacks from reaching your origin server, which protects your most sensitive information and files. Even in a worst-case scenario, where malware takes down a proxy server, that only affects service to that server. Users can still access your site through any of the other proxy servers since only cached copies are out of commission.

4. Increased site availability

Functionality and accessibility are obviously huge performance drivers. With traditional hosting, you need to add on servers as your traffic increases, and you’re at the mercy of a single server’s uptime and downtime.

If that single server is affected, it could mean your entire site is down, and you have no control on your end over recovery time.

A CDN reduces the amount of traffic without touching your main host server. It also has cache stores of most of your content, so if your main host goes down, a CDN can still display partial views of your site. That way, you remain online and accessible and gain some buffer time while the root issue is fixed.


How to choose the right CDN for your business

Picking the right CDN is essential, and there are many options on the market. Before you dive into CDN overload, take these important items into consideration about your own business and its needs.

1. Determine what type of content you will deliver

It’s a basic sentiment but an important one: What content will you actually be delivering on your site? Will you be focusing on video streaming, audio files, high-resolution images, long-form copy? Different content types demand different infrastructure and architecture.

Video and photos require a much higher degree of bandwidth than plain text, and a more customized and graphically enhanced website will need more bandwidth than a simple templated one. If you have mostly static content that isn’t changed very often, you can get away with far less bandwidth.

2. Set a budget and compare pricing

Obviously what you can afford will play a significant role in your decision. A good CDN should not only be of decent quality, but it should be transparent with pricing.

Typically, CDNs are priced in two ways. The first is via custom contracts that you negotiate with a sales team. This is a common practice with larger CDN providers. Depending on what features and how much bandwidth you need, your costs can vary widely.

With the second way, pricing is more usage-based, which tends to be the best for budgeting and planning. A CDN company will give you a per-GB rate that rises and falls with volume. This type of pricing will also typically vary by region.

3. Investigate network size

The size of the network is another vital factor. You should choose a CDN with a fairly decent network so there are enough servers to go around without becoming clogged and throttling traffic.

Usually the more servers you have, the faster and more reliable the service. Having more regions covered is also important so you have support for global traffic.

Keep in mind that size doesn’t always matter since a bigger network only goes so far. It’s crucial to investigate whether the available PoPs are guaranteed to actually be available for your content.

What matters even more than footprint is software optimization and quality of end-to-end connectivity.

4. Check out customer support

CDNs aren’t exactly an entry-level industry, so you’ll want to choose a company that offers good customer support to help with issues and questions beyond your capacity.

The setup itself can be a confusing process, so you’ll need access to people with technical knowledge and skills to help you through it should you get stuck. Look for an in-house call center, 24/7 availability, and phone access rather than just email.


CDNs can be a site saver

A CDN can help protect sensitive business data and increase the quality of the user experience for your business website.

Although it can seem a little overwhelming at first glance, taking the time to scope out your needs and work with a reputable CDN company can do wonders for increasing your business website’s speed, protection, and accessibility.

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