content distribution network

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A content delivery network is designed to send video, images, JavaScript, HTML files, and other content to users through a distributed server network. Generally the two protocols used for CDN delivery are HTTP and HTTPS; however, sometimes other protocols can be useful, as with video.

The primary reason CDNs are used is to improve content delivery performance. Before the rise of the CDN, you would have webpages with text and images on them. In order for all those elements to populate properly, you would have to send through dozens or hundreds of HTTP requests. Every time a request is sent, that means your browser is establishing a connection with a server, letting it know what it needs, downloading the information, and presenting it. You could have everyone connect to the same server. However, you can achieve better performance if you are able to get content as physically close to each user as you can.

CDNs are on the rise because of the considerable increase in the use of video and cloud services over the last few years. Reasons why CDNs are becoming so popular go beyond these trends, though. Once we look at why use of these systems is generally expanding and the benefits derived from them, we will take a closer look at how they work.

Video and cloud fueling CDN growth

CDNs have increased in recent years with the proliferation of video as a standard business tool. Video is resource intensive in terms of how much bandwidth it uses, as well as how much disk storage it needs.

The increase in cloud service and app use is sparking additional CDN expansion. Today it is considered commonplace to store essential company information in a third-party facility. CDN services are often offered in conjunction with cloud data and video storage since the two services bolster performance beyond your walls.

You will lower the amount of stress you are placing on your own data center by using the servers of the CDN to process and transmit data. Hence, you do not need as much hardware yourself, explained Kevin Tolly. Because you do not need as much equipment, that also means you do not need the facility space, cooling, and power that support it. Your capital and operating expenses decline.

Reasons for using CDNs go beyond lightening your load and cutting costs though. Here are 10 other key benefits:

Benefit #1: Distributed denial of service

DDoS attacks are terrible for websites, leaving you unable to respond to legitimate requests for hours as you are inundated with massive amounts of fraudulent traffic. As noted by technology author Simon Jones in TechFruit, a DDoS event means you cannot help prospects and customers during that time. You will be unable to usher leads and sales through your system. By taking advantage of the third-party infrastructure of a CDN and its DDoS protections, you can deliver high security and consistent service.

Benefit #2: SSL termination 

Content delivery networks do not always deliver static content but instead are simply a go-between from the application to the user. In this manner, CDNs are used both as a way to prevent breaches and to change the manner of the connection, freeing up the application’s servers. For application programming interfaces (APIs) and other highly active applications, organizations often decide to use CDNs for secure sockets layer (SSL) termination, which is a type of SSL offloading.

The way an SSL connection works is that you authenticate via software called a certificate prior to transmitting encrypted information from the client to the server. If you use a CDN for SSL termination, you are pushing work that must be conducted by the server (the authentication) to different hardware outside your own.

Benefit #3: Speed

The CDN will deliver the experience that consumers expect from the Internet. The reason that people like to shop online is due to its convenience, speed, and immediate support. E-commerce is no longer an enticing proposition when your servers are going down or there are unexpected delays. When your servers are not delivering speed, people will go to a site that better respects their time and delivers a more solid user experience.

Keep in mind that CDNs are increasingly needed as sites get more popular. Traffic is a good thing until it overloads your site and leads to widespread performance issues. You will ensure that you give the best possible UX to your visitors and are unlikely to see latency issues when you send traffic through a CDN.

Benefit #4: Worldwide reach

Related to the issue of speed, a content delivery network can be especially helpful when you have users spread out across the globe – because a well-designed CDN will be distributed internationally. Although there are advantages to using a CDN for any organization, those that will get the biggest benefits from them are those that have customers in the US, Asia, Europe, and other locations worldwide. In those cases, the UX for users across the planet will be bolstered. On the other hand, a website that has its infrastructure housed in New York and whose primary customer base is in New York will not see as strong of performance gains since geographical distribution is not a problem.

Benefit #5: Simpler operation

The use of a CDN offloads the amount of work that is performed on-premises. The operation of your organization’s IT should become simpler. Having less hardware under your own roof means you do not have as much equipment to store and maintain.

Benefit #6: Enhanced security

Along with optimized content delivery performance, security is also core to these systems – and it goes beyond the advantages of SSL termination and DDoS mitigation. Managed web application firewalls (WAFs) and bot defenses can be added. You get better longevity out of your in-house equipment by using the security features of CDNs to limit the load that goes through your internal security equipment.

Benefit #7: Image optimization 

You can also often combine CDNs with image optimization services. Whether someone is accessing you from a cellphone, desktop computer, or anything else, your images can be dynamically optimized for them. 

Benefit #8: Surge-ready / slashdot-friendly

Perhaps the worst thing that can happen to your site is to get a huge amount of real (non-DDoS) traffic – a massive opportunity – and then not be able to handle the influx.

This issue often arises when a large site links to a small site, pushing through a large number of referred visitors. This process, called the slashdot effect or simply slashdotting, results in a traffic surge that could render your site unavailable or at least very slow. Slashdots are not the only way you might become overwhelmed by traffic, of course. You might generate the traffic more directly too, noted Jones. For example, you might run a contest that creates excitement or have an ad campaign that goes viral.

If you ever have a situation in which big traffic comes through unexpectedly, you may not be able to handle the load, resulting in crashed systems. Using a CDN service will enable seamless and reliable operation in these cases. It will be able to take care of those large bursts and keep up with the demand – typically much more successfully than the origin servers can.

Benefit #9: Reduce your data center footprint

Reducing the carbon footprint of data centers is a critical concern for many organizations. The extent to which IT infrastructure is a sustainability issue is clear in the findings of a 2014 report from the National Resources Defense Council (NRDC). The NRDC determined that data centers at that point produced 200 million metric tons of carbon dioxide and used 3 percent of energy generated worldwide. Plus, the problem is growing more severe, with consumption expected to grow from 91 billion kilowatt-hours (kWh) in 2013 to 139 billion kWh in 2020. While using a CDN service does not do away with the issue of sustainability, tapping into the greater efficiency of a CDN will mean you are more environmentally friendly.

Benefit #10: Branch-office services

Content delivery networks are attractive to branch offices of companies – because branch locations must have content that uses the main location as the origination server and the CDN to deliver and store it. The branch can get DDoS mitigation protection and WAF service through this same process – allowing them to push work that is conducted by hardware at the branch to the CDN edge.

How the CDN works

Now that we better understand why the CDN is so popular, let’s take a closer look at what it does. It operates as a proxy for your resources and services. When your customers enter your web address, they will be redirected automatically through the domain name system to the correct CDN. Since that’s the case, your customers will usually not know a CDN is being used.

Leveraging dedicated points of presence (POP) itself and via outside internet service providers, the content delivery network is able to locate the content servers. Instead of using internet links, a CDN will often utilized private, dedicated lines to interconnect its edges.

Requests from your users are monitored and processed at the CDN edge. If the network is being used for its likeliest use case, static web content is inspected to see how updated it is prior to delivery. CDNs also make it possible to stream video stored within a CDN, in which case you do not need to burden your WAN or your own servers. Software updates, product catalogs, and other customer-facing files can be stored with your CDN as well – in which case they are also accessed and delivered straight from the CDN.

A high-performance CDN

Other reasons to use a CDN include geoblocking, better SEO, and higher resilience. While there are many different reasons to use one, the top benefit is speed – which relies heavily on proximity. At Total Server Solutions, our CDN nodes are close to your customers, wherever they are, leading to happier viewers, fewer abandoned carts, and more completed transactions! Get the reach you need.