DSA? FEO? Transparent Caching? CDN Value-Add Services Demystified
CDNs typically offer helpful services beyond content delivery, but trying to understand those services can be confusing. Here's a cheat sheet to the most common value-add services.
The term "value-add services" is frequently used by content delivery networks to describe services that don't fall under the typical commodity CDN business. It's hard to discern exactly what those services are, as most CDN vendors don't define it down to a product level. I get many questions asking what services are classified as value add, but the answer all depends on who you ask. The way I define it is that CDN services typically include four kinds of content delivery: audio/video streaming, audio/video downloads, software downloads, and small object delivery.
Services outside of those would be considered value add and would include things such as application acceleration, dynamic site acceleration, front-end optimization, mobile content acceleration, media management (transcoding, ad insertion, content protection), and a host of other services for the purposes of security and commerce.
Akamai Technologies in particular confuses the market because it breaks out part of the company's revenue based on services (products), while the other half is broken out by media and entertainment, which is not a product or service, but rather a vertical. Here are what I consider to be the most common services that would fall under the term "value-add services," the way I define it.
Dynamic site acceleration (DSA): Dynamic site acceleration is a suite of technologies and products that deals with optimizing dynamically served content across the network. Traditional DSA services often include TCP optimization, route optimization, connection management, on-the-fly compression, SSL offloading, and prefetching technologies.
Front-end optimization (FEO): Front-end optimization technologies help to reduce the number of page resources required to download a given page and make the browser process the page faster. FEO technology isn't used to bring content closer, but rather it makes the content itself faster by optimizing the client-side delivery of website resources.
Transparent caching: Transparent caching platforms make intelligent decisions about which content can and should be cached inside a carrier's network. By deploying intelligent caches strategically throughout their networks, operators can cache and deliver popular content close to subscribers and reduce the amount of transit traffic across their networks.
Licensed/managed CDN: Licensed and managed CDN refers to software and services aimed at helping telecoms, carriers, and service providers build and deploy their own CDN services inside their networks. Licensed CDN refers to the licensing of CDN software to the carrier, who then builds a CDN solution on its own. Managed CDN is when a service-based content delivery vendor helps build and manage the CDN component of the carrier's network for it.
Application acceleration: Application acceleration is a suite of technologies that combines fast packet processing with SSL acceleration, connection multiplexing, dynamic caching, and adaptive compression to improve application response times. These technologies enable enterprise customers to accelerate the delivery of internal, external, and latency-sensitive applications to distributed users across the internet or via their enterprise networks.
Mobile content acceleration: Mobile content acceleration technologies are designed to specifically eliminate latencies found on mobile broadband networks to reduce page load times on mobile devices.
In addition to these listed, there are a whole host of different services to handle things such as DoS attacks (security), custom and managed DNS, custom reporting, tracking and analytics (especially for ad delivery), and lots of pieces in the video ecosystem for managing and adding business rules around the monetization of video. This is how I would classify value-add services, but others may define it differently. How you would define it?
This article appears in the October/November, 2012, issue of Streaming Media magazine under the title "CDN Value-Add Services Demystified."