What is a CDN? How does a CDN Work?

What is a CDN? How does a CDN Work?

Discover what is CDN (content delivery network), and how it functions to ensure quick, efficient and secure transfer of website content and Internet services.

Content delivery networks have become an irreplaceable part of successful websites: this technology allows for fast, secure and failure-proof transfer of files. What’s the secret lying behind CDN, and which advantages it offers? But before that we need to find out what is a Content Delivery Network (CDN).

What is a CDN?

A CDN (content delivery network) is a chain of geographically distributes servers that function together to ensure quick delivery of website content. CDN helps to transfer various static assets including JavaScript, HTML pages, images, stylesheets and videos. CDN is steadily growing in popularity, and today the vast majority of traffic is delivered via CDNs, including traffic from such projects as Amazon, Facebook and Netflix.

An appropriately chosen CDN network can protect website from widespread hacker attacks, including DDoS attacks.

Does CDN equal a web host?

Since CDN does NOT host content, it will not replace a usual web host. However, such network will cache website content at network edge, which boosts overall website performance. A lot of websites trying to cover performance needs with traditional hosting in vain resolve to CDNs. By caching resources on edge servers, you can cut on hosting bandwidth, prevent interruptions in loading and improve security. All in all, CDN is a sensible choice for those who want to get rid of typical problems coming with usual web hosting.

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 met 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.

Main advantages of using a CDN

In fact, the benefits of introducing a CDN depend on the size of project and its needs, primary advantages for the vast majority of users can be divided into four main categories:

  1. Improvement of website loading times. When the content is distributed over multiple CDN servers (especially when it is combined with optimization), visitors enjoy much faster page loading. Users tend to abandon slowly loading websites, so a CDN can increase the amount of time spent on your website and reduce bounce rates. A quicker website means more potential customers and viewers, and more time dedicated to your pages.
  2. Reduction of bandwidth costs. As a rule, bandwidth cost is the primary expense for websites. Thanks to caching and optimization, CDN can reduce the amount of data that the origin server must transfer, which reduces bandwidth expenses for website owners.
  3. Better content redundancy and availability. A lot of hardware failures and huge torrents of traffic can obstruct normal website work. Thanks to distributed servers, a CDN can handle much more traffic and prevent failures better than origin servers.
  4. Higher website security. CDN can boost security by ensuring DDOS protection, improvement of security certificates and some other optimizations.

How does a CDN work?

In its essence, CDN is a network of servers that work together to deliver content as fast, cheap, reliably and securely as possible. In order to boost connectivity and speed, a CDN has servers at exchange points between various networks. Internet exchange points are key locations where various Internet providers connect to render each other access to traffic from their different networks. With the help of connection to these locations, a CDN provider can help you to cut on costs and improve transit times of data delivery.

Together with placing servers in IXPs, CDN also works with various organizations on usual client/server data transfers. CDN’s Points of Presence, or simply datacenters, are spread over the globe in strategic spots to boost security, prevent different kinds of failures and Internet congestion.

How does a CDN overcome latency?

Website content loading matters, because users click away from websites that load slowly. CDN services help to boost loading the following ways:

  • Since CDN has a globally distributed nature, the distance between visitors and website resources is greatly reduced. Now users don’t have to connect to the origin server no matter where it may be – a CDN allows them being connected with the geographically closer datacenter. Shorter distance means quicker service.
  • Software and hardware optimizations, including load balancing and solid-state hard drives also help to reach user data quicker.
  • CDNs may also cut down on the amount of data delivered by diminishing file sizes. It’s possible with such techniques as file compression and minification. Smaller files means faster loading times.
  • CDNs enable websites with TSL/SSL certificates by improving connection reuse and enabling TSL false start.

Keeping website 24/7 online? With CDN it’s possible!

Uptime is a crucial aspect for any website. Traffic spikes, hardware failures, hacker attacks – all of that has the potential to bring your server down and deprive users of access to your website. A worthy CDN can minimize downtime thanks to:

Load balancing, e.g. distribution of traffic over multiple servers, which makes it easier to handle sudden boosts of traffic.

Intelligent failover technique ensures uninterrupted service, even if one or several CDN servers fail because of hardware errors. In such case, traffic is simply redistributed to other servers that function.

If the entire data center experiences technical problems, Anycast routing will redirect traffic to another datacenter to make sure that users have stable access to your website.

How Data Security Is Provided by CDN?

Data security is a crucial part of CDN. It can keep a website protected with the help of TSL/SSL certificates that guarantee advanced encryption, integrity and authentication. CDN can improve security by many ways, though the list of services depends on provider.

CDN (content delivery network) is one of the most efficient modern methods of data transfer optimization, which can be pretty useful for blogs, small and large online businesses, e-commerce websites, and so on. Its multiple advantages certainly outweigh its cost!