The Print Deploy VDI client comprises 2 main components:
- System Context Service (SCS)
- User Context Tool.
Before going into details about each component, here are some definitions you might find useful:
User session | A session that runs in the hosted VMs (virtual machines). Can have a single session (one user per hosted VM) or multi-session (many users per hosted VM). |
Session printer | A printer that's installed directly in the VDI session from a host via a template or VM session. |
Client printer | A printer that's on the connecting client (can be redirected to the host). |
ClientName | Contains the hostname of the client machine inside a session. This is used as the ‘hostname’ identifier for Print Deploy, allowing the sysadmin to deploy printers near the client machines. |
Session ID | A unique identifier within the VDI Session that is used to trigger parallel instances of an application. |
The System Context Service
The System Context Service (SCS) component of the Print Deploy VDI Client is responsible for:
- communicating with the Print Deploy Server
- installing and uninstalling print queues
- session monitoring
- ensuring that queues are only available to the logged-in user.
Communicating with the Print Deploy Server
The SCS ensures queues are deployed to specific virtual desktop sessions by communicating with the Print Deploy Server and requesting the queues for the supplied thin client IP address.
Installing and uninstalling print queues
The SCS is responsible for installing the different types of print queues, such as direct print queues, and establishing server connections for server print queues.
Session monitoring
The SCS detects if the same user is running multiple sessions.
A typical scenario is a user logging into another terminal in another part of the building. In this scenario, the SCS detects Windows sessions that are running for the same user by continuously polling the Windows Session Manager to monitor the state of sessions, as well as any newly launched sessions.
The SCS extracts session details (such as the IP of the client the session is running on) and contacts the Print Deploy server to determine the queues to deploy/uninstall in the thin client running the session.
Ensuring that queues are only available to the logged-in user
Print queues are only made visible to the specific user logged into the session. Due to the level of privileges required to manage print queues, the SCS runs under system context privileges, essentially acting on behalf of a user.
The User Context Tool
The User Context Tool component of the Print Deploy VDI client serves up the UI for the end user. When the UCT is running It is represented by a small green icon visible in the System Tray.
Within the Print Deploy VDI Client UI, users mainly undertake 2 main activities:
- View deployed printer status
- Manage optional printers
Only the TRUST mode is supported. That means the user logged in to the thin client is the correct user in PaperCut and belongs to the appropriate groups. This user’s identity will be used for authentication purposes.
Known limitations
- Citrix clients are not included in the “Computers connected in the last hour” count (this is displayed in the zone details, within the PD admin UI).
- When a default printer is set for the zone, the Citrix Client will not honor this (that is, the default printer will not be set).
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