What Is Content Delivery Network, What It Is Used for and How Does It Work

If you access the Internet via a smartphone, tablet or computer, it is natural for you to notice the differences in speed, reliability, and user experience of different applications and websites.

Why do some websites keep crashing, while there are countless others that deliver superior performance in similar situations? Well, the performance differs because of CDN.

So, what does CDN stand for? CDN is the short for "content delivery network," which is one of the core components responsible for the accelerated delivery of dynamic Internet content across the globe.

In this article, we’ll talk all about CDN — what is it? How does CDN work? The different types of CDN, and what are the benefits of using a CDN? 

What Is CDN?

A content delivery network (CDN) is a geographically dispersed network of servers and data centers. The goal of CDN is to facilitate increased web performance and high availability by locating web content copies closer to the end-users.

CDN servers are often referred to as "edge servers" since all CDN servers are located on the "edge network" — closer to end-users than a host server from which an application or a website originates.

CDN servers store or cache copies of various web content subsets from a host server, such as applications, video, audio, images, and HTML files. The content delivery network, by bringing web content nearer to end-users, allows website publishers to control bandwidth consumption, reduce load times, and provide enhanced performance.

Content delivery networks currently serve over 50 percent of the world's web traffic. The percentage keeps rising as more and more enterprises expand their reach to newer markets and offer more diverse types of content. Companies typically purchase content delivery network services from content delivery network providers, who manage and maintain their network of servers.

How Does CDN Work?

Let's use an example to get a clearer understanding of how CDN works. For instance, you have a website on a server based in Australia. Now, if an end-user accesses your website from France, the content delivery network will serve the user from a France-based edge server - closest to the end-user - instead of serving the request from the origin server in Australia. This improves application performance, ensures fast content loading, and also boosts the user experience.

In addition to minimizing the gap between end-users and web content, the content delivery network distributes the traffic load as well, so that traffic requests do not overwhelm a single server.

The Advantages of Using a CDN

eCommerce websites, live-streaming media services, cloud application developers, gaming companies, and content-intensive enterprise websites rely on content delivery networks to offer better service to their end-users. Key benefits of a content delivery network include:

Improved Scalability and Connectivity:

In addition to facilitating end-users with faster load times, which translates into greater user experience, a content delivery network also rewards web publishers with increased traffic, higher page views, lower site abandonment, and stronger customer engagement.

Decreased Bandwidth Consumption:

Web hosting companies charge businesses for any data they transfer from origin servers. A content delivery network, by storing web content copies closer to end-users, ensures less data transfer from origin servers, thereby reducing enterprise costs and bandwidth consumption.

Lower Latency:

Typically, an end-user requests for data and the system transfers it in response. Latency is the lag between the request and the response, which increases as the distance between end-users and servers widens. Since CDN servers are on "network edge" - nearer to end-users - they reduce the latency, optimizing performance.

Effective Traffic Spike Management:

Viral videos, limited-time offers, or successful marketing campaigns can trigger a sharp and unanticipated spike in the demand for content. Leveraging load balancing for the distribution of demand across web servers, the content delivery network prevents traffic spikes from affecting website performance.

Enhanced Cybersecurity:

A content delivery network employs automation and data analytics tools that help identify firewall issues, MITM (Man in the Middle) threats, and DDoS (Distributed Denial of Service) attacks.

Amplifies User Satisfaction:

Media playback issues, unresponsive applications, and slow load times are the primary reasons that make end-users avoid/abandon particular websites. A content delivery network minimizes performance issues, which boosts user satisfaction.

Accelerated eCommerce:

A content delivery network facilitates quicker payment approvals, faster product page loading, and seamless transactions on mobile and desktop devices, enhancing the shopping experience. CDN also enables B2B and B2C eCommerce retailers to deliver applications and content speedily, even during times of high traffic.

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Types of CDN

For website visitors, the type of content delivery network hardly matters. What matters to users is performance, reliability, and security. However, for webmasters, the type of CDN is important. Below are the CDN types webmasters use.

Peer-to-Peer Content Delivery Network

This CDN technology leverages the Peer-to-Peer (P2P) protocol that users of µTorrent are somewhat familiar with. Besides µTorrent, many NGOs and big corporations, such as AT&T, use the P2P method for web content distribution. In P2P content delivery technique, caching is not involved. Here, the end-users are part of the CDN, who simultaneously upload web content components while downloading or accessing live-streaming. Because of lower resource and hardware usage, a number of CDN providers, including Freecast, PPS.tv, and PeerCast offer free Peer-to-Peer services.

Push CDN

The Push CDN methodology refers to a content delivery network type, where origin servers, manually or automatically, send web content to CDN servers directly. Content is cached on CDN servers unless it is purged or deleted. The core concept of Push CDN is that webmasters are responsible for sending content to CDN servers. The content they "push" is the content that will be delivered to visitors when the system receives a request.

Pull CDN

Exactly the opposite of Push CDN, in Pull CDN, content delivery networks are responsible for "pulling" web content that is served to end-users once a request is received. In the Pull CDN environment, webmasters allow the content to remain on origin servers, but rewrite URLs so they point to CDN servers. When a user makes a request, the CDNs "pull" web content from origin servers and deliver it. The CDN servers then cache the web content until its expiration.

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CDN in Cloud Computing Career

Today's consumers crave the flexibility, simplicity, and speed of cloud-based services, but they are disinclined to compromise the scalability, security, performance, and reliability offered by a content delivery network.

Keeping that in mind, leading Cloud service providers, including Amazon Web Services, Google Cloud Platform, and Microsoft Azure are integrating CDNs into their cloud computing tools and platforms to facilitate consistent performance and ease of management to their users.

The integration of content delivery networks into cloud platforms is the latest technology trend that, according to numerous reports, will further widen the existing talent gap in the cloud computing domain and drive the demand for skilled personnel to new heights.

To effectively address the talent shortage, Amazon, Google, and Microsoft are placing less emphasis on academic degrees, and are instead opting to hire certified cloud professionals who have a deep understanding and hands-on experience of cloud computing processes.

If you are aspiring to pursue a career in the cloud, a Post Graduate Program in Cloud Computing or an AWS Solutions Architect Certification from an industry-recognized institution can open the door to a variety of employment opportunities. Click here to know more about the market-leading certification courses. 

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Simplilearn is one of the world’s leading providers of online training for Digital Marketing, Cloud Computing, Project Management, Data Science, IT, Software Development, and many other emerging technologies.

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