What is a CDN?

Introduction:

Site speed and reliability are critical to keeping your customers happy and driving sales. 9 out of 10 customers will give up on a site if it takes too long to load. 

A Content Delivery Network (CDN) addresses both these issues by caching and serving your website's files from local servers and providing layers of security, including protection against DDoS attacks. 

Read on to learn what a CDN is and discover how it can boost your performance, improve your customer experiences, and help drive conversions.

What Is a CDN?

A Content Delivery Network (CDN) is a system of distributed servers that deliver web content and pages to users based on their geographic locations to improve performance and reduce latency. It caches and stores your website's essential files, such as HTML pages, JavaScript files, CSS files, images, and videos, on edge servers, resulting in shorter load times. 

How Does a CDN Work?

A CDN works by distributing your website's content across a global network of edge servers to route users to the closest edge server for faster load times. 

Here’s a breakdown of how it operates:

• Content Distribution: A CDN stores copies of your website files on edge servers around the world, helping speed up content delivery and minimizing load delays.

• Edge Servers: Your business' content is cached on these strategically positioned servers. Customers accessing your site are routed to the edge server with the lowest latency, typically the server that is physically closest to them.

• Load Balancing: CDNs employ sophisticated algorithms to monitor and load balance traffic across the edge server network. More optimal routing decisions and greater resilience mean no single server has to carry too high a load, maintaining optimal performance even as website usage rises.

• Data Retrieval: When an end user requests access to your site, the nearest edge server delivers it directly to them without having to retrieve it from your origin server. 

• Content Purging and Updating: CDNs also constantly purge, or remove and update, content. This ensures that users always receive the most up-to-date content without companies having to worry about serving outdated information.

CDN vs. Traditional Hosting

It’s important to understand the difference between these two delivery models to choose the right solution for your website and applications. Let’s explore the essential aspects of each.

Traditional Hosting

A traditional approach to hosting relies on centralized servers that handle all internet traffic and file requests for a website. This can create bottlenecks that slow down load times, especially when traffic spikes. 

Traditional hosting has the following defining characteristics:

• Uses a single data center or hosting location to serve all website files

• Long distances between users and servers can cause delays

• Bottlenecks are common when traffic ramps up quickly

• Outages and downtime affect access to the website for all users

CDNs

A CDN takes a different approach, with distributed servers placed in multiple locations. This allows for faster content delivery and more reliable access for your users.

Here are the main features of a CDN:

• Caches files at geographically distributed nodes

• Delivers content from the server closest to each user

• Load is balanced across the network, improving performance

• If one location fails, other servers can still accommodate your customers

6 Benefits Of Using a CDN

CDN’s have become an essential tool to enhance the performance of websites and applications and guarantee the best user experiences. Let's explore the six key benefits of implementing a CDN, to demonstrate why they've become a crucial component of modern web infrastructure:

• Reduces latency: An effective CDN minimizes the delay between a data request and the delivery by caching and storing your website's content on servers close to your customers, which means less waiting time.

• Enhances performance: With content being served from local edge servers, your customers will spend less time waiting for pages and assets to load, including those with high-bandwidth, media-rich content, leading to higher satisfaction levels thanks to the smoother user experience.

• Improves security: The best CDNs provide additional layers of security, for example by: 

  • Safeguarding against DDoS attacks by filtering traffic to identify malicious requests

  • Large, high-bandwidth, globally distributed CDNs are able to absorb excess traffic and prevent it from hitting your origin server.

  • Safeguarding data with Transport Layer Security (TLS) and Secure Socket Layer (SSL) certificates that ensure a high standard of authentication and encryption.

  • Offering Web Application Firewalls (WAFs) to analyze and channel every HTTP request, blocking application layer (Layer 7) threats, only allowing secure traffic through. 

  • CDNs can use detection technology to quickly identify and neutralize bots that perform automated tasks and can be used for malicious attacks.

• Reduces costs: By caching content, a CDN lowers the volume of data that needs to be transmitted to and from your origin servers. This results in lower infrastructure expenses for your business, as the same content reaches more end users but requires fewer resources. CDNs can also help reduce bandwidth costs by rerouting traffic from the origin server to the CDN's servers.

• Increases scalability: During busy periods, such as Black Friday sales or new product launches, a CDN easily scales to handle unusually large traffic surges to your site. This on-demand scalability allows companies to normalize their server spend and avoid paying for wasted storage during off-peak times.

• Boosts visibility: Site speed is a significant factor considered by search engines. By improving load times through caching and content delivery, a CDN positively influences how search engines view your site. With better visibility, you can gain more organic traffic and exposure.

• Improves availability: CDNs allow websites and apps to be "always on", avoiding error messages frustrating your end users. If an origin server goes down, the CDN can continue serving whatever content was last in cache to users from geographically and strategically distributed points of presence (POPs).

What Are the Use Cases Of CDNs?

CDNs are widely used by businesses across industries to enhance key experiences for both customers and employees. 

Some of the main use cases include:

• E-commerce: From retail to hospitality, a CDN will enhance customers' shopping experience by loading product pages faster, making checkout more convenient, and increasing security around transactions. It can also handle heavy traffic and regulate seasonal and unexpected traffic spikes.

• Media and Entertainment: A CDN is crucial for smoothly streaming videos, games, and music. It prevents buffering, so your users can enjoy their content uninterrupted.

• Online Learning: Educators rely on CDNs to reliably host course materials and conduct live virtual classes, ensuring students have no issues accessing the resources they need.

• News Websites: Serving news from a CDN allows readers worldwide to receive the latest updates, even during periods of heavy traffic. 

• Financial Providers: CDNs quickly and securely load applications for banking, investing and other financial services, easing customers access. They can also cache APIs to serve highly dynamic content like stock prices.

• Social Media: Reduced latency and fast content delivery across different devices optimizes how users interact on platforms, especially important for sites with high traffic volumes and rich multimedia content.

• Healthcare: Patients and health care staff can access medical records and telehealth services without risky delays.

• Gaming: Online gamers can enjoy smooth, lag-free experiences across devices thanks to the low latency of CDNs.

• Digital Publishers: Companies with large global readerships can use CDNs to handle traffic, page downloads, transactions, and other demands.

• Tech Companies: CDNs support real-time analytics and log management at the massive scales required by SaaS providers. They can deliver actionable insights and analysis that companies can use to constantly improve the user experience.

Example Use Case: A CDN in Action

Let's look at a use-case example to understand how a CDN provides a quicker and more efficient way of serving content to users.

Take an end user visiting a favorite news website. Once they type in the URL to initiate communication between the browser and the news site server where the webpage is hosted (the origin), the back-and-forth communication between the user's browser and the origin goes through a number of steps: first relaying the DNS lookup, then routing, then a TCP and TLS handshake, and finally the HTML transmission, along with various files like CSS, JavaScript, and videos or images on the news site.

Now, let's say the user is in San Francisco, and the news site server is in New York. Remember that all the communication between the user's browser and the news site server happens over real wires and cables. So, the physical distance between San Francisco and New York adds time, or "latency," to the browsing experience. Imagine if our user was in Australia and the communication had to travel back and forth between Australia and New York! As you might predict, that distance would dramatically increase latency, degrading the user experience.

In contrast, let's picture this scenario again – this time, using a CDN.

We know that the closer the user is to the news site server, the faster the experience will be. CDNs put servers physically closer to end users — thereby speeding up load times.

With this knowledge, the news site has opted to "cache" — meaning, temporarily store — its content on CDNs. Now, instead of going back and forth between New York and San Francisco, the user's browser can communicate with a server much closer to home. And for the user over in Australia, their browser can connect to a POP in that part of the world, for example, Sydney.

And because cached content is only stored temporarily, CDNs also purge, or remove and update, content constantly. Companies don't have to worry about serving their users outdated content; the most up-to-date content is delivered automatically. As a result, not only will our user's article load significantly faster, but they'll also see the latest headlines as the day unfolds. A CDN has dramatically enhanced the user experience — and, we might presume, the loyalty to visit that news site again and again.

How to Choose the Best CDN Provider

A CDN can add significant value by optimizing web performance and enhancing your end users’ online experience, resulting in enhanced brand reputation and loyalty. Indeed, by increasing performance, availability, scalability, and security, all while reducing costs, CDNs are a win-win for any online businesses. Whether you're running a bustling e-commerce site, a media-rich blog, or a high-traffic web application, implementing a CDN can significantly improve your online presence and user satisfaction. 

But with countless providers vying for your attention, how do you separate the wheat from the chaff? 

Here are the essential factors to consider when selecting a CDN provider to keep your digital assets running smoothly and your users coming back for more:

Assess Your Needs

Before beginning your search, consider your specific requirements. To ensure coverage, consider factors like the average traffic volume for your sites, your customers' geographic locations and security needs. 

For example, a high traffic volume may require more servers across more regions, while sensitive data apps could require advanced protection measures. 

Performance And Reliability

Look for a provider with a track record of consistently speedy delivery with minimal interruptions. Solid performance metrics and uptime percentages indicate reliable infrastructure that can scale with your business. Also, check for positive reviews from other customers to ensure they provide a dependable service.

Global Coverage

An extensive global network of servers ensures rapid loading wherever your audience are, preventing delays that could damage your brand perception. Wider dispersion also affords you the flexibility to expand into new markets. 

Security Features

Look for capabilities such as protection against DDoS attacks and SSL/TLS support for encrypted connections. Advanced access controls ensure only authorized users can manage your content, protecting your customers and business data.

Scalability

You want traffic to your sites and apps to increase, so choose a provider designed to scale cost-effectively and keep pace with your evolving needs. 

Customer Support

Opt for a provider that stands behind their service with responsive assistance whenever needed. Dedicated support and an assigned account manager simplify management and troubleshooting. Around-the-clock help with fast responses avoids disruptions for your end users.

Cost-Effectiveness

Consider factors like data transfer limits and additional services that impact overall costs. Choose a model that aligns with your budget and anticipated returns. 

Integration And Ease Of Use

Select a provider with straightforward integration options for your existing platforms and tools. Your employees should also find the system simple to operate so they can focus on other responsibilities. 

Why Fastly Is Your Best Choice for CDN Solutions

Traditional hosting alone cannot meet the expectations of today’s always-online customers. Choosing the right Content Delivery Network (CDN) can make or break your online presence. While every CDN claims to solve your speed and reliability concerns, the right solution must offer a comprehensive set of features to deliver on this promise.

Fastly's CDN solution stands out for its versatile capabilities and impressive track record. Fastly has the robust infrastructure to ensure your sites, apps, and APIs run at maximum speed with built-in security and scalability. 

Fastly’s key benefits include:

• Global Edge Network: With 291 Tbps of global edge capacity, Fastly’s CDN ensures swift and reliable content delivery, minimizing delays and optimizing user load times worldwide​.

• Efficient Caching: Fastly offers, on average, 150ms cache invalidation globally, allowing for speedy updates and ensuring end users receive the most current content without delay​.

• Quick Deployment and High Accuracy: Security solutions like WAF can be deployed in minutes and offer 90% effectiveness in blocking malicious traffic with minimal false positives​.

• Instant Log Data: Fastly delivers 100% of log data in real-time, allowing you to gain immediate insights for monitoring and troubleshooting​​.

• Elastic Scaling: Fastly also supports automatic scaling without capacity constraints, making it ideal for businesses enjoying rapid growth or need to deal with variable traffic patterns​​.

• Vendor Consolidation: Fastly’s unified platform consolidates multiple services (like CDN, security, and compute), offering cost savings and simpler admin by reducing the need for multiple vendors​.

• High Customer Satisfaction: Fastly consistently achieves high customer satisfaction scores (98% CSAT) and offers lightning-fast response times (10 minutes for enterprise response) with effective issue resolution​.

To learn more about how Fastly's CDN can help your business thrive, sign up for a free trial today.