The Application Delivery Infrastructure (ADI) spans the distance between the datacenter where the applications are hosted and the endpoint device where they are consumed. This span can be logically segmented and roughly mapped to fit the typical physical boundaries found between users and applications. At the highest logical level, the diagram below shows the technologies that could be used to deliver applications by following a data packet from the hosting infrastructure through to its consumption by the user.
In the datacenter, the application delivery infrastructure stack starts with the server and networking infrastructure. The link between this hardware layer and the operating system layer above it is increasingly being intercepted by virtualization technologies. At the front end of the application are those components that facilitate application delivery beyond the datacenter to the user. The choice of component used depends on what type of application is being delivered---Web, Windows, or the entire desktop. Beyond the front end are the components that secure and optimize application delivery to where it is consumed by the user. The delivery loop is completed by monitoring the user experience, data about which is then fed back to the data-center to enable decision-making about existing or future delivery session sessions.Because an application cannot execute without an operating system, the application delivery process begins with the methods that provision these operating systems to the hardware infrastructure. The common bare-metal configuration where a single operating system instance runs on a dedicated piece of hardware is slowly being augmented by hardware virtualization technologies, such as system virtualization and server provisioning. These technologies facilitate the de-coupling of server platforms, allowing operating system images to become mobile, moving across the entire hardware platform when required. When these operating systems are used to run Windows applications or desktops, their delivery is controlled through server-side app virtualization technologies. When the applications are Web-based, control is achieved through optimization.
Securing the application transmission once it leaves the datacenter perimeter, and controlling the type of delivery and access to data is done by an application access gateway. Optimization of network traffic is primarily a function of the WAN Optimization Controller. While providing real-time feedback on application delivery performance from the end-user's perspective, regardless of whether the application is executed at the end-user device or the datacenter, the application experience monitor interacts with each of the other ADI components to ensure that monitoring is truly end-to-end.At the highest level, the application delivery process consists of four stages: control, secure, optimize, and manage. For effective functioning, each stage has certain dependencies on the others. Within each stage are supporting technology functions and, together, they make up the entire application delivery process. The technologies that support the ADI are:
