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Citrix Universal Printer (CUP) 3.4.1, CUP Overview

Above we described Citrix's solutions for local client printing and network printing:

UPD: solve the problems of many printer drivers in Citrix VDA, such as conflicts, memory leaks, tedious management and maintenance, and possible system crashes.

UPS: solve the problems caused by traditional Windows network printing in Citrix VDA, such as slow printing speed, high bandwidth consumed by branch printing, and often need to install and update printer drivers combined with UPD.

Through these two solutions, the user experience of printing problems in Citrix environment is improved. But in this case, if the user has more session printers, there are several or even a dozen, when the user logs in, it actually has an impact on the user's login time. The more these session printers, the longer they will be enumerated. When a user logs in under the Citrix environment, when VDA sends the login ticket given by the user to DDC for session request, DDC will prepare a series of things for the user session, including the user credentials stored in STA first. Ticket is only the mapping of the user in STA. DDC enumerates the user's credentials through the Ticket generated by STA. After enumerating, the user's session is prepared according to the user's credentials. The information of the session also includes the user's Citrix policy, session information, printer and other information. Among them, if the user has too many printers, it is too long to enumerate the printers when generating the user session, which undoubtedly increases the user login time and affects the user experience.

In order to solve the login performance problems caused by too many printers, Citrix developed Citrix Universal Printer (CUP). The Citrix Universal Printer (CUP) is a universal printer object, and if the user enables the Citrix Universal Printer (CUP), the universal printer is automatically created when the session is created and is not bound to any specific printer. This means that if the user needs to map 10 printers, after using the Citrix General Printer, when their session is created when logging in, the Citrix session creates only one printer object (Citrix Universal Printer). In such a scenario, only one printer object is created. This can greatly reduce resource usage and login time.

The Citrix Universal Printer is enabled by setting the Citrix policy to automatically create a general-purpose printer when the session logs in. By default, the Citrix Universal Printer will be mapped to the client's default printer, which means that when this general-purpose printer prints, its print task is previewed through the EMF preview window and is transferred to the client's default printer without selecting a printer. Since it is by default, you can modify this behavior, for example, when you click print, as shown in the following figure:

The universal printer pops up an EMF-based preview window to print the document:

Then in this print preview interface, which is rendered through EMF Viewer, users are required to select their compatible local or network printer and then print. By default, the default printer that is directly connected to the client is not selected to print. When we click the printer button on the EMF Viewer interface, a selection box for selecting a real printer pops up:

This selection list is all the printers on the user client that Citrix enumerates for the user through CPMS when the user needs to print, including locally directly connected printers and network printers. At the same time, Citrix General printers use the Citrix Universal print driver and are only compatible with the Windows operating system. Citrix Universal printers are most suitable for priority users who have many local and network printers and require fast session login speeds.

At the same time, the interesting difference between the general-purpose printer created based on UPD and the real printer of the mapped client is that the general-purpose printer cannot set up the local real printer, because the general-purpose printer is just an existence similar to a virtual PDF printer, and there is no real device to deliver with it, only a preview file is produced based on the EMF file when printing. Only when you select a real printer will you enumerate and answer settings such as the printer properties of the real printer on the client side.

3.4.2. CUP deployment

The deployment of CUP is simple and only needs to be enabled in the Citrix policy: create general-purpose printers automatically.

This policy allows or disables the automatic creation of generic Citrix universal printer objects for the session when using user devices compatible with generic printing. Generic printer objects are not created automatically by default.

Some policies that need to be configured are:

General print EMF processing mode. Controls how EMF spooling files are processed on Windows user devices. By default, the system processes EMF records directly in the background to the printer. With direct background processing into the printer, background processors can process records faster and use fewer CPU resources.

General print Preview preferences. Specifies whether to use the print preview feature of an automatically created printer or a generic printer.

Universal driver preferences. Specifies the order in which the system attempts to use the universal print driver, starting with the first item in the list. You can add, edit, or delete drivers and change the order of drivers in the list.

Client printers are automatically created, and this policy is disabled.

Citrix PDFPrinter (CPP) 3.5.1, CPP Overview

Citrix PDF Printer (CPP) is similar to CUP, both belong to the category of Citrix General Printer object, except that CPP prints the document as a PDF file, and then prints the PDF file through a real printer; while CUP generates a print file through the EMF file, and then prints previews through EMF Viewer, and then selects a real printer to print. The general application scenario of Citrix PDF Printer (CPP) Citrix PDF printer is in the case of using Citrix Receiver ForHTML5 or Citrix Receiver ForChome, which is not suitable for Receiver such as Receiver under Windows and Linux.

The printing process is shown in the following figure:

When you click to print, select the Citrix PDF printer, then print the page as a PDF file, then save it, and then find a real printer to print it out. Like CUP, Citrix PDF printers are implemented using Citrix UPD.

3.5.2. CPP deployment

The deployment of CPP is to enable Citrix policy: automatically create PDF universal printers

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