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WordPress Basics: How Does A Content Distribution Network Make Your Site Faster?

November 19, 2014 0 Comments RSS Feed

Content Distribution NetworkPerformance-optimized web hosting is the single most important factor in determining site speed. Without that, your site is going to be slow no matter what other optimizations you make. But although good quality web hosting is a necessary component of a low-latency site, it’s not sufficient. The fastest web hosting can’t accelerate a badly coded site with huge unoptimized images and a ton of social media widgets. A decent optimization strategy can fix all of those issues, but there’s one thing no amount of on-site optimization can improve: the round-trip time for geographically distant web clients.

Many people are under the misconception that Internet communications travel at the speed of light. Sometimes they do, but only if they’re traveling over radio waves to satellites or other wireless communication scenarios. In fibre optic cables, signals travel less quickly than the speed of light in a vacuum—the reason is complex—and in copper cables they are significantly slower.

It’s fact of physics that no amount of optimization can overcome. And packets don’t travel in a straight line from server to browser; they go through numerous switches and routers on the way, each of which slows them down a little. The further a site’s server is from the browser, the longer packets are going to take to traverse the network.

So, if we can’t make the speed of light faster, we have to find another way of reducing the round-trip time. The solution is the obvious one: move the server so that it’s closer to the browser. Of course, you can’t move the actual server every time someone requests a page from a long way away—we haven’t invented teleportation just yet (although I keep my fingers crossed).

Instead of physically moving the server, we create a copy of the information it contains and send it to a server close to the user. In fact, we can make dozens or even hundreds of copies of the site or some parts of the site and put them on servers all over the world. Those servers are called edge nodes. When someone in Australia wants to look at a site in the US, the signal isn’t sent all the way across the Pacific and back. Some clever DNS technology recognizes that the request is coming from Australia and routes it to one of the copies of the site that is in a nearby data center.

In a nutshell, that’s how a content distribution network works.

Content distribution networks and WordPress

Although that all sounds quite complicated, it’s not especially difficult to integrate a content distribution network with a WordPress site. The W3 Total Cache plugin makes it straightforward to add a content distribution network to WordPress. If you’d like some help setting up a CDN, take a look at our managed CDN service, which uses the EdgeCast CDN.

Posted in: WordPress