ADN(Application Delivery Network)
An Application Delivery Network (ADN) is a suite of technologies that, when deployed together, provide application availability, security, and acceleration. At the core of an ADN is the Application Delivery Controller (ADC), an advanced traffic management device that is often also referred to as a web switch, content switch, or multilayer switch, the purpose of which is to distribute traffic among a number of servers or geographically dislocated sites based on application specific criterion.
The ADN evolved from layer 4-7 switches in the late 1990s when it became apparent that traditional load balancing techniques were not robust enough to handle the increasingly complex mix of application traffic being delivered over a wider variety of network connectivity options.