Printing With Lpd - Black Box LE3840A Manual

Part B: lpd and Host-side Printing Options

6.3 Printing with lpd

lpd is our implementation of the standard UNIX line printer daemon that lets
you print across a TCP/IP network without installing software on your host—
with all filtering and banners done by the Ethernet Print Server. Remote
printing uses the same commands (lpr, lpq, lpc) as local printing.
The process begins when lpd finds a printer on a remote system by looking
at the remote (rm) entry in the /etc/printcap file for that printer.
lpd handles a print job for a remote printer by opening a connection with
the lpd process on the remote system and sending the data file (followed by
the control file containing control information for this job) to the remote
system. lpd then filters the data and prints the job according to information
contained in the control file and its own printcap file.
lpd recognizes the format of a certain data type and filters the data, if
possible, so it can be printed on the type of printer you specify. You can
instruct lpd what type of printer is attached to the Ethernet Print Server port
one of two ways. First, you can run the nsconfig utility from a UNIX host.
Second, you can accept the default port settings (PCL on ports 1 and 2,
and PostScript on ports 3 and 4).
You also have the option to configure the port for both PCL and PostScript
data. This feature is useful if you have an emulation-sensing printer that
prints both data types.
Intelligent Queue
lpd provides an intelligent queue (IQ) feature that can route an incoming job
to an idle printer. IQ provides load balancing by eliminating the chance that
a job will have to wait at one port when another is available.
When to Use IQ
For example, if you have four PCL printers in a printer room attached to an
Ethernet Print Server, you should define on local printer and specify IQPORT
as the remote printer name. Performance is improved because multiple jobs
do not queue up waiting for a printer while another sits idle.
If a printer runs out of paper or requires service, only the job currently
being printed is delayed. Incoming jobs are automatically routed to an open
printer. IQ simplifies setup even more by stipulating that one logical printer
be used to filter and print automatically all types of jobs. And you need only
one short printcap entry per Ethernet Print Server.
CHAPTER 6: UNIX Printing through TCP/IP
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