Endpoint device submits user credentials to a Web Interface site through Access Gateway. All external communication is between endpoint device and datacenter occurs over SSL port 443.

Web Interface passes the user credentials to the DDC. The DDC installation process automatically creates multiple Web Interfaces sites to provide flexible user experience.

The DDC verifies user authorization by performing a Microsoft Active Directory query with the user's credentials.

The DDC queries the Data Store for the user’s assigned desktop groups. Desktop groups consist of users and desktops assigned through Active Directory (AD).

Using the desktop group it obtained from the Data Store, the DDC queries the Virtual Machine infrastructure about the status of the desktops within that group.

Provisioning Services binds the vDisk to the virtual desktop.

The DDC identifies to Web Interface which desktop it assigned for this particular session.

Note: This step might have already occurred if an available desktop is running in an idle pool when the user logs on.

Web Interface sends an .ICA file to the Desktop Receiver, which points to the virtual desktop identified through the DDC in Step 7.

The Desktop Receiver establishes an ICA connection to the specific virtual desktop that was allocated through the DDC for this session.

The VDA verifies the license file with the DDC.

The DDC queries the Citrix License Server to verify that the user has a valid ticket.

The DDC passes session policies to the VDA, which then applies those policies to the virtual desktop.

Profile management applies user profile settings to the virtual desktop.

The Desktop Receiver displays the virtual desktop to the user.

As the user interacts with the virtual desktop, XenApp delivers the hosted and streamed applications on demand for Virtual Desktops.