Networking: A Beginner's Guide
Working with Printers
Before setting up and working with printers on a network, you need to understand the
components involved in network printing and how they interact.
Understanding Network Printing
A print job is a set of binary data sent from a network workstation to a network
printer. A print job is the same data that a computer would send to a locally connected
printer--it's just redirected to the network for printing.
The network workstation that sends the print job to the print queue is responsible
for formatting the print data properly for the printer. This is done through software
installed on the workstation, called a print driver, which is specific to each type of
printer. Printer drivers are also specific to each operating system that uses them. In
other words, an HP LaserJet 5si driver for a Windows XP computer is different from a
HP LaserJet 5si driver for a Windows 2000 workstation computer. More troublesome,
different versions of the same operating system sometimes use different drivers, so a
driver for a Windows XP computer might not work with a Windows Vista computer
and vice versa.
Print jobs are often sent to the network through a captured printer port. The
network client software redirects to the network one of the printer ports on a
networked workstation, such as LPT1. The process of redirecting a printer port to a
network printer is called capturing. Usually, captured ports are persistent and continue
through multiple logins until they are turned off.
Print jobs sent to the network go to a place called a print queue. The print job sits in
the queue until the network can service the print job and send it to the printer. Print
queues can hold many jobs from many different users and typically are managed in a
first-in, first-out fashion.
Print jobs are removed from print queues and sent to actual printers by print servers.
After sending the complete job to the printer, the print server removes the job from the
queue. You can accomplish print serving in many different ways. If the printer you are
using is connected to a server or workstation on the network, that server or workstation
handles the print server duty. If the printer is directly connected to the network (if it
has its own network port), then the printer usually has a built-in print server as part
of its network hardware. This built-in print server has the intelligence to log in to the
network and to service a particular printer queue.
Print jobs start at the printing application, which sends its printer output to the
local operating system. The local operating system uses the printer driver requested
by the application to format the actual print job for the printer in question. The
local operating system works with the installed network client software to send the
formatted print job to the print queue, where the job sits until the printer is available.
Then the print server sends the print job from the queue to the actual printer.
Many steps are involved, but once everything is set up, it works smoothly, as you
will see in the next section. Figure 17-14 shows an overview of how network printing