Every time a user accesses a website, it needs to send data from its server back to the user’s device. If this user is physically far from the ‘origin server’, the data has farther to travel. Large files or live streaming may be impacted by delays if there is no CDN in place.

A content delivery network (CDN), or content distribution network, contains a series of servers that deliver web applications or web content to users based on their geographical location. This content may include text, video, images and so on – which often impact page load times.

A CDN offers additional servers, based in various physical locations. These ‘caching servers’ render copies of the content from the origin server, which then travel to the user. Depending on where the visitor is, the request will go to the closest CDN node, and the data will be sent back as quickly as possible. This improves website performance and offers other commercial benefits.

CDN vs. cloud computing

While CDNs may sound similar to cloud computing, there is a key difference. Cloud computing can serve content from geographically separate web servers. In addition, cloud computing offers services like on-demand data storage and computing power.

On the other hand, CDN providers focus solely on caching content for routing to end users in different locations.

Both CDNs and cloud computing involve serving content from multiple servers in various locations, however cloud computing covers a broader range of services beyond content delivery e.g. storage and computation. In contrast, CDN specialises in optimising content delivery.

How does a CDN work?

A reliable CDN service is rooted in connectivity. Digital Realty’s colocation connectivity service offers scalability and security, providing a better user experience. Typically, a content delivery network uses three types of servers:

1) Origin servers

The origin server is where your content is originally hosted. Its primary purpose is to wait for requests to come in from users – such as a visitor accessing a web page – and process them.

2) Edge servers

An edge CDN server offers cached versions of static content. These reduce bandwidth consumption for origin servers. They are Points of Presence (PoP), providing access points for multiple networks to connect to.

3) Domain name server (DNS) servers

DNS functionality takes a domain name and translates it into an IP address to access website content. Sometimes referred to as a ‘phone book’, the domain name server answers the queries and signposts them to edge servers when necessary.

With global user requests, all three of these services may be activated. For example, if we have web traffic from London accessing a site in Los Angeles, we might see:

The initial request goes to a DNS server

It is then signposted to edge servers

The edge servers provide cached versions of content from the origin servers, thereby improving load times and web performance.

What are the benefits of using a CDN?

There are several CDN benefits for website owners, from reduced bandwidth costs to risk mitigation. For example:

Faster page load times

Without a CDN, network traffic may have to travel significant distances, which slows down loading times. This may prove frustrating for users, particularly if they are shopping around and know they can get answers or products faster. A content delivery network provides a faster data transfer, leading to higher engagement and conversion rates.

Improved user experience

Page load times go hand in-hand with the user experience. As brands experiment with new mediums on websites and social media, their users have bigger demands – such as fast-loading images or video content. With access to more content formats and faster delivery, brands can answer user questions and/or make sales.

Search engine optimisation (SEO) advantages

Since the 2021 Google Core Web Vitals update (and its subsequent iterations), user experience has been one of many key SEO metrics. Google stipulates that faster-loading sites improve user experience (UX). It therefore rewards these sites, providing they also comply with other best-practice ranking factors.

Reduced downtime

Uptime is an absolute essential for all websites, but particularly e-commerce vendors or sites that face traffic spikes. A CDN distributes content across a network of servers, helping with load balancing. If thousands of users try to access real-time video streaming around the world, there’s less chance of a server crash if the traffic is distributed evenly.

Worldwide coverage

Brands that wish to expand their reach globally can rely on CDNs to get their message across faster. This may be particularly helpful for e-commerce, media and entertainment sites. For example, if a breaking news story comes out internationally, it may attract traffic from users all over the world.

Website security

As cyber threats continue to advance, we see more cases of bots, distributed denial of service (DDoS) and ransomware attacks. A CDN offers DDoS protection by distributing malicious traffic requests. An attacker may try to overwhelm servers by sending bot traffic to a site – a CDN can ward this off with load balancing.

Equally, CDNs offer encryption layers when paired with updated secure socket layer/transport layer security certificates. These layers protect against malicious activity that may lead to data breaches or network crashes.

Cost-effectiveness

By caching content, CDNs reduce bandwidth costs for a website. Bandwidth costs are directly connected to web hosting fees, so if webmasters can optimise capacity, they will save money. This is ideal if they have high traffic and/or use rich media on their sites, such as video content.

With each of these benefits in mind, CDN service providers are ideal for industries such as:

E-commerce – protecting against site crashes during high-traffic periods like online sales.
Media and entertainment – helping users around the world access breaking news and video content.
Healthcare – helping telemedicine patients get vital information faster, including diagnoses and prescription details.
Financial services – offering enhanced security for customers when transacting
SaaS – improving uptime for software as a service (SaaS) brands dealing with daily operations.
Gaming – allowing users to access visually demanding graphics globally, in real time.

Integrating a CDN with cloud services helps multiple industries deliver web content faster. Digital Realty’s cloud partners can help these brands create a scalable infrastructure for CDNs.

CDN storage

While CDNs are perfect for hosting dynamic content, they can also store large volumes of content media. Companies with significant storage requirements – for example, an e-commerce store with a vast product range – can offload their storage needs through caching.

These servers can store and serve content, including images and videos, freeing up infrastructure to handle traffic loads more effectively.

Expand your reach with Digital Realty’s worldwide data centres

If you’re expanding your digital footprint, get the competitive edge with Digital Realty. Our strategically positioned data centres are designed to drive edge services for CDNs, offering efficient storage and faster loading times. Get in touch today to hear more about PlatformDIGITAL and other connectivity services.

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FAQs

What Is an example of a CDN?

Some examples of companies that offer CDN services include Cloudflare and AWS Cloudfront. We work with partners including AWS, Cloudflare, Microsoft Azure, Google Cloud, and many more.

How do I store on a CDN?

To store data on a CDN, you need to host data on servers close to your customers. Our expert teams can advise you on migrating your data to one of our dedicated facilities. Get in touch to find out more.

Is CDN an object storage?

A CDN works for both object storage and unstructured data such as videos. Content delivery networks can use object storage to cache and distribute content to users around the world.

What Is the difference between DNS and CDN?

A domain name service allows users to find the right web server by translating URLs into IP addresses. By comparison, a CDN allows this data to travel back to the end-user faster using a network of edge servers to display cached content.

How does CDN improve performance?

A CDN improves performance by speeding up the delivery of content. Modern websites use programming languages such as HTML and JavaScript to create multi-media content. This can slow down page load times, particularly if the request needs to travel a significant distance to an end-user. A CDN reduces this distance by caching content on edge servers.

What Is the responsibility of a CDN?

A CDN has multiple responsibilities, primarily to reduce page load times for websites. In turn, this helps to increase uptime by distributing traffic demands across multiple servers. This can also help with SEO and ultimately improve the user experience.

How can I use a CDN for my website?

You can use a CDN for your website if you have significant storage needs, high traffic volumes, or global traffic. A CDN will help to serve cached versions of your content all over the world, thereby increasing website speed and meeting user demands faster.

A Guide to Content Delivery Networks