CDN and Simultaneous Connections
For many Websites, the biggest single advantage of using a CDN is the concept of maximising the number of persistent connections and simultaneous downloads possible. In simple terms, your Internet Browser limits the number of connections to a server to between 4 to 8 concurrent connections. This means that between 4 to 8 items load at a time. Many Websites are made up of at least 50 items (components). If you’re using a reasonably high speed Internet connection then the limit of loading between 4 and 8 components simultaneously becomes a bottleneck.
A CDN alleviates this limit as the CDN delivers content from a different server to your primary domain name. Immediately therefore the concurrent limit it less of a limit i.e. you now have Website content delivered from two servers with your Browser allowing between 4 and 8 connections to each server. Using Amazon Cloudfront (or some other CDNs) combined with sub-domains it’s possible to increase this value nine-fold or even more (e.g. my Website delivers content from https://organicweb.com.au, http://cdn1.organicwebcomau.wpcomstaging.com, http://cdn2.organicwebcomau.wpcomstaging.com etc. allowing a large number of concurrent connections).
CDN and edge locations
Many of the good CDNs offer distributed edge locations (or peer locations) and this is another means of having faster Page load times. What this means is that copies of your CDN content is stored in various distributed locations. When a request is made for data in the CDN then the data is delivered from the edge location closest to the request. This has the effect of both reducing the load on centralized servers and networks as well as reducing the distance the data needs to travel to the requester.
Amazon ClodFront has edge networks in over 20 locations. If someone visits my Site from New York then they’ll have content delivered from the edge location in New York and if someone from Sydney visits my Site then content will be delivered from Singapore (this is the closest CloudFront edge location to Australia).
Which CDN to use?
Above are just two of the advantages of using a Content Delivery Network with your WordPress Site. If you are planning on using a CDN then here are some CDN providers with good reputations and relatively low cost:
Amazon CloudFront: From Amazon Web Services (AWS): Amazon CloudFront is a web service for content delivery. It integrates with other Amazon Web Services to give developers and businesses an easy way to distribute content to end users with low latency, high data transfer speeds, and no commitments.
MaxCDN: From MaxCDN: Simply put, MaxCDN gives you the most powerful control panel and CDN product in the industry – at a price you can afford.
Rackspace Cloud Files: From Rackspace: Cloud Files, powered by OpenStack
Who should use a CDN?
Quite simply, anyone that is serious about Search Engine Optimization (SEO) and getting better results from their Website should be using a CDN. Using a CDN has reduced substantially in cost and the benefits are significant in terms of reducing Page load speed (my Page load speed, as measured by Google, has reduced by over 300% since using a CDN).
If you want to speed up your WordPress Site using a CDN then contact me. For a small fee I’ll have you up and running with a CDN quickly.