Continued…
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 PoPs). 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 London accesses your US-hosted website, it is done through a local UK PoP. This is much quicker than having the visitor’s requests, and your responses, travel the full width of the Atlantic and back.
This is how a CDN works in a nutshell. Of course, as we thought we needed an entire guide to explain the inner workings of content delivery networks
Pretty much everyone. Today, over half of all traffic is already being served by CDNs. Those numbers are rapidly trending upward with every passing year. The reality is that if any part of your business is online, there are few reasons not to use a CDN especially when so many offer their services free of charge.
Yet even as a free service, CDNs aren’t for everyone. Specifically, if you are running a strictly localized website, with the vast majority of your users located in the same region as your hosting, having a CDN yields little benefit. In this scenario, using a CDN can actually worsen your website’s performance by introducing another unessential connection point between the visitor and an already nearby server.
In an ideal world, a CDN would be an integral part of any website hosting. However, when CDNs were first established in the late 1990s, they were far too expensive and only accessible to the largest organizations. Today things have changed and many hosting providers actually do offer CDN services as a checkbox add-on.
Using a CDN.
or a CDN to work, it needs to be the default inbound gateway for all incoming traffic. To make this happen, you’ll need to modify your root domain DNS configurations (e.g., domain.com) and those of your subdomains (e.g., www.domain.com, img.domain.com).
For your root domain, you’ll change its A record to point to one of the CDN’s IP ranges. For each subdomain, modify its CNAME record to point to a CDN-provided subdomain address (e.g., ns1.cdn.com). In both cases, this results in the DNS routing all visitors to your CDN instead of being directed to your original server.
If any of this sounds confusing, don’t worry. Today’s CDN vendors offer step-by-step instructions to get you through the activation phase. Additionally, they provide assistance via their support team. The entire process comes down to a few copy and pastes, and usually takes around five minutes.
Overall, CDN evolution can be segmented into three generations, each one introducing new capabilities, technologies and concepts to its network architecture. Working in parallel, each generation saw the pricing of CDN services trend down, marking its transformation into a mass-market technology.