What is Content Delivery Network (CDN): What Why and How?

Hello Folks, welcome back to Learnizo Global. Whether we know it or not, every one of us interacts with CDNs on a daily basis; when reading this article, shopping online, watching YouTube videos, or perusing social media feeds. No matter what you do, or what type of content you consume, chances are that you’ll find CDNs behind every character of text, every image pixel, and every movie frame that gets delivered to your PC and mobile browser. Content delivery networks (CDN) are the transparent backbone of the Internet in charge of content delivery. This article will focus on providing insight on the whys, whats, and hows of a CDN.

What is a CDN?

A content delivery network (CDN) refers to a geographically distributed group of servers that work together to provide fast delivery of Internet content.

A CDN allows for the quick transfer of assets needed for loading Internet content including HTML pages, JavaScript files, stylesheets, images, and videos. The popularity of CDN services continues to grow, and today the majority of web traffic is served through CDNs, including traffic from major sites like Facebook, Netflix, and Amazon.

A properly configured CDN may also help protect websites against some common malicious attacks, such as Distributed Denial of Service (DDoS) attacks.

While the delivery of website content is a common use for CDNs, it’s not their only function. In fact, CDNs deliver a wide variety of content that includes: 4K and HD-quality video, audio streams, software downloads such as apps, games, and OS updates, and much more. Potentially any data that can be digitized can be delivered through a content delivery network.

CDN and Web Host

While a CDN does not host content and can’t replace the need for proper web hosting, it does help cache content at the network edge, which improves website performance. Many websites struggle to have their performance needs meeting by traditional hosting services, which is why they opt for CDNs.

By utilizing caching to reduce hosting bandwidth, helping to prevent interruptions in service, and improving security, CDNs are a popular choice to relieve some of the major pain points that come with traditional web hosting.

What are the benefits of using a CDN?

Although the benefits of using a CDN vary depending on the size and needs of an Internet property, the primary benefits for most users can be broken down into 4 different components:

Improving website load times – By distributing content closer to website visitors by using a nearby CDN server (among other optimizations), visitors experience faster page loading times. As visitors are more inclined to click away from a slow-loading site, a CDN can reduce bounce rates and increase the amount of time that people spend on the site. In other words, a faster website means more visitors will stay and stick around longer.

Reducing bandwidth costs – Bandwidth consumption costs for website hosting is a primary expense for websites. Through caching and other optimizations, CDNs are able to reduce the amount of data an origin server must provide, thus reducing hosting costs for website owners.

Increasing content availability and redundancy – Large amounts of traffic or hardware failures can interrupt normal website function. Thanks to its distributed nature, a CDN can handle more traffic and withstand hardware failure better than many origin servers.

Improving website security – A CDN may improve security by providing DDOS mitigation, improvements to security certificates, and other optimizations.

How does a CDN work?

To minimize the distance between the visitors and your website’s server, a CDN stores a cached version of its content in multiple geographical locations (a.k.a., Points of Presence, or PoP). Each PoP contains a number of caching servers responsible for content delivery to visitors within its proximity.

In essence, CDN puts your content in many places at once, providing superior coverage to your users. For example, when someone in Bangalore accesses your US-hosted website, it is done through a local India PoP.

CDNs can reduce the amount of data that’s transferred by reducing file sizes using tactics such as minification and file compression. Smaller file sizes mean quicker load times.

CDNs can also speed up sites that use TLS/SSL (Transport Layer Security/ Secure Socket Layer) certificates by optimizing connection reuse and enabling TLS false start.

Reliability and Redundancy – How does a CDN keep a website always online?

Uptime is a critical component for anyone with an Internet property. Hardware failures and spikes in traffic, as a result of either malicious attacks or just a boost in popularity, have the potential to bring down a web server and prevent users from accessing a site or service. A well-rounded CDN has several features that will minimize downtime:

Load balancing distributes network traffic evenly across several servers, making it easier to scale rapid boosts in traffic.

Intelligent failover provides uninterrupted service even if one or more of the CDN servers go offline due to hardware malfunction; the failover can redistribute the traffic to the other operational servers.

In the event that an entire data center is having technical issues, Anycast routing transfers the traffic to another available data center, ensuring that no users lose access to the website.

Data Security – How does a CDN protect data?

Information security is an integral part of a CDN. a CDN can keep a site secured with fresh TLS/SSL certificates which will ensure a high standard of authentication, encryption, and integrity. Investigate the security concerns surrounding CDNs, and explore what can be done to securely deliver content.