What code is installed on virtual desktops and enables direct FlexCast Management Architecture (FMA) connections...

Comprehensive and Detailed Explanation From Exact Extract of Nutanix End User Computing documents:

According to Citrix Virtual Apps and Desktops architecture documentation utilized in Nutanix EUC designs:

VDA Functionality: The Virtual Delivery Agent (VDA) is the essential software component that must be installed on every machine (virtual or physical) that delivers applications or desktops.

FMA Role: The VDA registers with the Delivery Controller (Broker) and manages the FMA (FlexCast Management Architecture) connection between the machine and the user device. It establishes and manages the HDX connection, allowing the Citrix Workspace app (on the client side) to connect directly to the desktop session.

Distinction:

Citrix Workspace app is installed on the client device (endpoint), not the virtual desktop.

VirtIO drivers are lower-level drivers for disk/network I/O virtualization on AHV, not FMA connection brokers.

NGT provides Nutanix-specific fabric features (SSR, FLR), not Citrix session connectivity.