Chapter 18: Printing | Citrix Access Suite 4 for Windows Server 2003: The Official Guide, Third Edition

Since the inception of networking, printing has been a primary concern during the design and implementation phases of building networks. Whether the issue is quality of the print job, bandwidth needs, performance requirements, paper tray demystification, or simply determining "Where did my print job go?" administrators have struggled with providing secure, fast, and simple printing solutions to their users. This chapter explains the Windows printing environment, shows the options available to administrators within MetaFrame XP, defines terminology unique to SBC printing, and provides a troubleshooting section for systematic resolution of the most common problems. Third-party print driver utilities are also discussed as alternatives for managing the SBC print environment beyond the tools inherent in MetaFrame XP.

Windows Printing Explained

From the perspective of most users, printing is a very simple process. Type some text into an application, click the printer icon in the toolbar, and pick up the pages from the printer. Unfortunately, things aren't so simple for a system administrator. Devoting just a bit of thought to the difficulties of printing in complex environments is enough to give the average administrator a headache. In a less complex printing environment, the client computer, print server, and printer (or print device if you are fluent in Microsoft-speak) are typically all located in a single well-connected LAN environment. When printer problems occur, an administrator is able to walk to all of the devices involved in the print process to investigate and troubleshoot problems. As companies grow, expanded LANs and WANs complicate printing. The print server, client, and printer may all be on different segments of the network with some components located at different physical sites.

In an SBC environment these three key components (client, printer server, and printer) are often located across WAN links. New concepts and new terms also exist in an SBC environment, which must be understood in order to effectively design, implement, and maintain that environment. Printing problems cause end-user frustration and, in turn, cause users to reject new technology. With proper planning, testing, consideration, and a good troubleshooting methodology, however, SBC printing can be managed and work properly.

The Windows Print Process

The Windows environment effectively shields the end user from the complexities of the print process. However, to appreciate the difficulty of developing and maintaining a complex and robust print environment, an administrator must understand the fundamentals of the print process.

When a Windows user clicks the print icon, the following occurs:

The application generates an output file including document formatting called an enhanced metafile (EMF).
The EMF is sent to the local print spooler.
From the EMF file, the local print spooler generates a spool file using a print driver. The spool file includes printer-specific information needed by the printer to create the final document.
The print job is queued by the print spooler in the local spool folder and forwarded to the printer or print server where it is transformed from print commands to hard output.

In SBC environments the MetaFrame server acts like a regular client workstation during printing. The application running from the Terminal Server generates the EMF, the EMF file is sent to the local print spooler, and a spool file is generated. The spool file may then be sent directly to the printer, to the print server that holds the queue for that printer, or to a client connected to the MetaFrame XP server where it is re-spooled to the printer or print server.

The MetaFrame XP Print Architecture

Users in an SBC environment can print to the following types of printers:

Printers connected to ports on the user's client device on Windows, WinCE, DOS, Linux, UNIX, or Mac OS platforms.
Virtual printers created for tasks such as printing from a PostScript driver to a file on a Windows client device.
Shared printers connected to print servers on a Windows network.
Printers connected directly to MetaFrame XP servers.

The printer objects that ICA clients use can be categorized by connection types. There are three kinds of printer connections in a MetaFrame XP server farm: client connections, network connections, and local connections. This chapter refers to printers in a server farm as client printers, network printers, and local printers, depending on the type of connection they have in the farm.

Client Printers

Client printers are defined differently depending on the ICA Client platform.

On DOS-based and WinCE client devices, a client printer is physically connected to a port on the client device by a cable.
On UNIX and Macintosh client devices, a PC or PostScript printer connected to a serial port (or a USB port for newer Macintoshes) is considered a client printer.
On 32-bit Windows platforms (Windows 9x, Windows NT, Windows 2000, and Windows XP), any printer that is set up in Windows (these printers appear in the Printers folder on the client device) is a client printer. Locally connected printers, printers that are connected on a network, and virtual printers are all considered client printers.

Network Printers

Printers that are connected to print servers and shared on a Windows network are referred to as network printers. In Windows network environments, users can set up a network printer on their computers if they have permission to connect to the print server. In a MetaFrame XP environment, administrators can import network printers and assign them to users based on group membership. When a network printer is set up for use on an individual Windows computer, the printer is a client printer on the client device.

Local Printers

A local printer is a printer created by an administrator on the MetaFrame XP server using the Add Printer Wizard from within the Printers applet in the Control Panel. Like a network printer, print jobs printed to a local printer bypass the client device and can be sent either to a Windows print server or directly to a printer, depending on how the printer has been created on the server. If the printer is added to the MetaFrame server with the port pointed to a share such as \\printserver\sharename, then the print job is sent to the print server before heading to the printer. The print queue can be Windows-, NetWare-, or UNIX-based. If the printer is added and the port specifies the actual printer itself (such as an lpr queue to the printer's IP address), then the MetaFrame server is essentially the print server, and the job is sent directly to the printer. Local printers are not typically utilized in an enterprise MetaFrame XP environment because of the need for the administrator to set up every printer in the environment on each MetaFrame XP server. However, local printers can be utilized successfully in smaller MetaFrame XP farms (three or fewer servers).