User guide

Unix - TCP/IP
Page 54
Chapter 2 Installation and Configuration
Printing Methods
There are 4 printing methods to choose from. All are explained in the following table. Select
whichever is the most convenient in your environment.
Printing method Description
LPD LPD is a standard print method for most UNIX systems. The benefit
of this method is that it eliminates the need to install additional
software on the host.
The problem is that in most cases the LPD protocol sends out the
data file before the control file. The IOPRINT+ Print Server will print
the data file immediately, ignoring any print options set in the control
file. To solve this problem, use PSfilter instead.
PSfilter PSfilter is a proprietary print method provided with the IOPRINT+
Print Server. The benefit of this method is that it provides many print
options such as banner print, copies, and so on. To use PSfilter, a C
compiler must be installed on every UNIX host so that the PSfilter
source code can be compiled into executable code and installed on
the UNIX host.
FTP (File Transfer
Protocol)
FTP is also a standard print method in most UNIX systems, but it is
NOT recommended except as a test and back-up method of
printing.
LPD and PSfilter work well with a large number of users because
they both employ print queue processes.
FTP does not implement a print queue. If the printer is busy, the print
command will fail, creating an error situation.
Direct Socket
Interface
The Direct Socket Interface (DSI) is a Unix-based method of
providing a "direct" connection between a host computer and a
printer. The host and the IOPRINT+ Print Server establish a TCP
connection, using a special socket number. All data sent over this
connection is treated as print data, and sent transparently to a logical
printer defined on the IOPRINT+ Print Server.