What is a CDN?

At its most basic level, a content delivery network (CDN) can greatly improve the end-user experience of a website or application by moving cacheable content closer to that end user.

Akamai Cloud Embed (ACE) CDNs use our Edge network servers to cache and deliver this content. There are definite benefits to delivering content through our Edge servers:

  • You'll see faster delivery of content to the end user
  • You'll accomplish offload of processing from the origin server
  • You'll get reduced egress bandwidth from the origin server.

When content is delivered from a server near the end user, the shortened distance reduces latencies. As a result, duplicate requests for the same content (for example, 10,000 end users all requesting the same video of a cat) can be handled at the Edge servers. So, the request load and bandwidth use at your origin server is greatly reduced. This frees the origin server to handle more unique requests, or requests for dynamic content.

How is the CDN put in place?

Put simply, you place the Edge network between the end users and the origin server through a simple reassignment of the domain name for website or application your customer (our "subcustomer) owns. For example, imagine the mapping from the website domain to the origin server IP was direct, like this:

Website hostname Origin server IP
www.example.com 93.184.216.34

The Edge network can be inserted by generating a CNAME of the website to the Akamai domain, which points the end user request to the Akamai Edge server IP, rather than to the origin server.

Website hostname Akamai edge hostname Edge server IP
www.example.com www.example.com.akamaiedge.net 184.51.102.67

The Akamai Edge server then uses a separate hostname when addressing the origin server:

origin hostname origin server IP
origin-www.example.com 93.184.216.34

How are CDN behaviors configured?

When an end-user request arrives at the Akamai Edge server, the server understands how to handle the request by consulting a "base configuration" you've set up for your customers' websites or applications, and a "delivery policy" you've set up comprised of settings for a specific subcustomer."

The Edge server looks at the Host: header value in the request, and then finds the corresponding property configuration file for that website or application. You set up this configuration using the Property Manager in Control Center (recommended), or via the Property Manager API. You apply general rules for caching, authorization, origin server location, and other services, that apply to all subcustomers.

You also set up a "delivery policy" for each subcustomer, to define match criteria and behaviors to apply to requests that come in for that specific subcustomer's website or application. This is done via the ACE API.