Virtual Application Terms Defined

Just when you thought you had seen enough of the term Application Delivery Controller (ADC), along comes another swift witted marketing department to try to change the game. At the end of the day, they are all just ADC’s. Radware has recently tried to change the name game by introducing a Virtual Application Delivery Infrastructure (vADI) which contains their SoftADC or Virtual Application Delivery Controller (vADC). Running multiple of these vADC’s results in what they call a ADC-VX, or a server with a hyper-visor such as Xen, VMware or Hyper-V – or did they develop their own Hypervisor to compete with these three. If the terms are new, the concept is borrowed. Bluecoat refers to an Application Delivery Network (ADN) which is no different than an Application Delivery Infrastructure (ADI). F5 thinks there is a Unified Application Delivery – although anything “Unified” is so last decade.

Here is some focus:

ADC – Application Delivery Controller

A Traditional software/hardware appliance based solution. Typically sits between the users and the application server or web server. ADCs are built specifically for Application Acceleration which includes Load Balancing, TCP Multiplexing, SSL Offload, SSL Multiplexing, Caching, Compression, Rate Shaping, Content Switching, Content Filtering, Content Redirect. The Citrix NetScaler is best at these based on performance ratings and customer feedback. The traditional ADC is a product of ’00’s where silicon valley companies built their software to run on purpose built hardware.

SoftADC – Software based Application Delivery Controller

The ADC software without it’s mated hardware. Depending on which operating system stack your ADC was built on, your ADC is just software with some high performance hardware to match. A Hard ADC if you will, might have common attributes of most hardware appliances, however, it is tuned with specific functions to accelerate the application acceleration features of the software – such as a hardware card specifically for SSL Acceleration to increase the speed at which SSL cryptography can be handled.

vADC – Virtual Application Delivery Controller

Take the SoftADC and plug it into a virtual hosting environment, and you now have the Virtual ADC. Citrix NetScaler VPX was first to market with the solution, as the other vendors run to catch up. Citrix NetScaler VPX runs on all Hypervisors – Xen, Hyper-V, VMWare. Citrix NetScaler VPX takes advantage of multiple processors or vCPU’s and virtual switching capabilities. Also refered to as a Virtual Network Appliance (VNA) which can run on any hardware platform that supports virtualization such as HP and Dell.

AaaS – ADC as a Service

A type of ADC emerging with cloud providers as a provisionable service within a specific cloud computing environment such as Amazon Web Services, Rackspace, Rightscale, Softlayer, GoGrid and others. Could also serve as Platform as a Service (PaaS) and Infrastructure as a Service (IaaS). Usually results in a custom kernel developed specifically for that cloud provider, depending on their cloud based infrastructure. Some classify this as Software as a Service (SaaS) as well.

More terms and definitions can be found here




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