- Integration Factors to Consider
- The Linux Solution
- File Services
- Print Services
- Edge Services
- DNS/DHCP Servers and Routing
- Web Servers
- Workgroup Databases
- Light Application Servers
- Computation Clusters
- Data Center Infrastructure
- Enterprise Applications
- Messaging and Collaboration
- Internal Development
- Power Workstations
Printer sharing ranks right up with file sharing as a major motivation for networking. Network printing has definitely evolved over the years to where almost any printer can be shared over a network. However, printers have primarily been accessed through Windows workstations, and the common printing scenario involves using the Windows printer manager to direct print jobs.
Two things have changed that, for many organizations, makes network printing slightly more complex. These changes include the Internet with its ability to connect to any resource, anywhere in the world, and the emergence of Linux and its integration within the enterprise network arena. Technology from Novell and the open source community that leverages the Internet and integrates Linux printing includes Novell iPrint and CUPS.
How Internet Printing Works
Both iPrint and CUPS are based on the Internet Printing Protocol (IPP). IPP is a printing protocol that is designed to work over Internet protocol (IP) and support printer access control, authentication, and encryption. It is much more secure, especially for public networks, than earlier printing protocols. Common Unix Printing System (CUPS) was developed for the Unix and Linux communities as a standard printing system that simplifies the accessing of printers and writing of print drivers, which has historically been a problem as all variants of Unix had their own printing system. A single print driver written to CUPS can support a wide range of file formats. CUPS is an open source solution and, as of this writing, the CUPS database includes 244 drivers for 1,233 different printers.
Using CUPS, a printer can be identified using a uniform resource identifier (URI) and, if configured to do so, can be accessed from any device on the Internet. Printers can be standalone units with built-in print servers (software/hardware combinations that deliver print data to a particular printer), or can be attached to workstations (Windows, Linux, and so forth) that include the print serving software. CUPS can deliver print jobs to an attached printer, to a printer on the local area network, or to a printer connected via IP across the Internet.
Novell iPrint provides similar Internet printing capability, but also adds some useful functionality. One of the primary difficulties in printing to remote locations across the Internet is in locating and correctly identifying a specific printer. URI and uniform resource locator (URL) names are hard to keep track of. iPrint solves the problem by providing Hypertext Markup Language (HTML) web-accessible map images that provide users with the capability to graphically search or drill down to find the desired printer in a specific location. Locating a printer for remote printing is simple and intuitive. Novell iPrinter utilities allow administrators to easily create any custom printer map to give end users simple ways to find and install printers (see Figure 3.7).
Figure 3.7 Novell iPrint helps locate remote printers and automatically configures the workstation for printing.
Users printing from a workstation to a network printer can only do so if the print drivers for that particular printer model have been installed and configured on that particular workstation. Remote or unfamiliar printers tend to present driver location and configuration problems, which iPrint now alleviates. When a user locates any printer hosted by iPrint, the appropriate drivers for that printer are automatically downloaded, installed, and configured and appear as part of the standard Windows printer selection list. Desired driver settings can be determined by the administrator prior to the printer being installed on the workstation. Printing across the Internet becomes as easy as printing to the printer on your desk.
How Internet Printing Is Implemented
You have multiple options for installing IPP-based printing using either iPrint or CUPS. Novell iPrint includes three components: the iPrint server software, the iPrint client, and the iPrint Map Designer. The iPrint server software installs on NetWare or Linux and handles all the IPP requests. The iPrint client is a plug-in for a standard browser that acts as a gateway, translating Windows print requests to IPP and sending those requests to the Novell IPP server. The iPrint Map Designer is a browser-based design tool that administrators can use to create a graphical representation of the location of iPrint printers.
Installing an iPrint server is accomplished via the standard install methods for each operating system. iPrint installs as part of a new server installation or at a later point using the iPrint install CD. When installed, iPrint is managed and accessible to users via a web page. To install the iPrint client, users simply go to the iPrint web page, click the Install iPrint Client option, and the client plug-in is installed automatically.
To locate a printer, users again go to the iPrint web page, navigate an iPrint map to locate the desired printer, and then click on it. The drivers are downloaded and configured on the workstation automatically. With a Windows client workstation, iPrint installs the printer in the Windows print manager, and it appears as any other local or network printer. The iPrint client is also available for Linux clients.
One of the great advantages of iPrint is that driver information for all printers is centralized. As part of iPrint setup, you create an iPrint Driver Store that maintains a collection of drivers for all types of printers. There's never a need to go looking for print drivers when a new client needs to be configured.
iPrint can be managed using Novell eDirectory, with access to printer objects and drivers based on a user's identity. Individual users, groups, or complete organizations (containers) can be granted access to individual printers or groups of printers. Novell's iManager, a browser-accessible management interface, also can be used to manage iPrint (and printer access management as well).
iPrint server works virtually the same way installed on Linux with access to IPP services via a web browser. The iPrint server includes the driver store, specific printer agents redirect printer-ready files to a printer (see Figure 3.8), and the entire solution can be managed for access through eDirectory (which also runs on Linux as well as NetWare and Windows).
Figure 3.8 Novell iPrint configuration for Linux.
IT managers have the option of implementing traditional Linux printing services as well. As mentioned, Linux Internet printing is based on CUPS and provides access to printers through Linux-based printer servers and print queues. CUPS can be installed and printers administered through YaST. Printing from Linux can be done either through the Linux command line, from a graphical interface such as KDE, or from an application. Linux also supports LPRng and lpdfilter, traditional Linux printing services.
Samba, the open source Microsoft SMB/CIFS emulator, can also play a major printing role when Linux print servers and print queues are used with Windows clients. Samba allows CUPS printers to be printed to and accessed from Windows workstations, just like a common Windows or NetWare network printer. Samba handles the print job forwarding, queuing, and print management. Samba lets a Linux computer function as a Windows server by enabling the computer to provide Windows print services to end users. Samba also lets a Linux workstation function as a Windows client by enabling it to access and use Windows print services, whether they originate on a Windows server or a Linux server with Samba installed. The Samba implementation provided by Novell focuses on providing authenticated file services from the Linux server to Windows clients with access control being managed by eDirectory.
You can see that that there are multiple print options whether you are running a Linux-only shop or, like most organizations, a mixture of Windows, Linux, and NetWare. With a straight Linux data center operation, you can still enjoy the benefits of iPrint with mapped access to Internet-connected printers. Client workstations (Windows or Linuxit doesn't matter) can access printers regardless of the print server platform. Linux can access Windows print services and vice versa. iPrint simplifies locating printers, driver storage, and workstation configuration for everyone.