Citrix 3 4 VDA

A XenDesktop site is made of many components: hypervisors, server OS instances, Delivery Controllers, License Server and so on. The keystone that lets all those moving parts work together is the Virtual Delivery Agent, the VDA. The VDA is the software you install on every virtual or physical machine running a Windows server or desktop operating system that you want to publish as a resource to your users.

Once the VDA is installed, it communicates with the Delivery Controller through the FMA stack, while the Receiver software installed on the client device communicates with the VDA over the ICA/HDX protocol. When the connection is internal, the VDA and Receiver establish a direct end-to-end connection. When the connection is external, traffic flows from the client to NetScaler Gateway, then from NetScaler to the internal network and finally to the VDA. If the client does not have a Receiver installed, the HTML5 web Receiver embedded in StoreFront takes over.

Where to install a VDA

• On virtual desktops (Windows 7, 8, 10) used for VDI scenarios.
• On server OS instances (Windows Server 2008 R2, 2012 R2) used for hosted shared apps and desktops.
• On physical PCs for the Remote PC use case.

The VDA also makes efficient use of GPU and graphics features when needed (HDX 3D), which is essential for graphics-intensive use cases. In the next video we will discuss the FrameHawk acquisition and what it brings to the protocol stack.