Novell LINUX ENTERPRISE SERVER 10 - INSTALLATION AND ADMINISTRATION 04-08-2006 Installation Manual page 458

standard. Manufacturers then provide drivers for only a few operating systems, elimi-
nating difficulties with those systems. Unfortunately, Linux drivers are rarely provided.
The current situation is such that you cannot act on the assumption that every protocol
works smoothly in Linux. Therefore, you may have to experiment with various options
to achieve a functional configuration.
CUPS supports the socket, LPD, IPP, and smb protocols. Here is some detailed in-
formation about these protocols:
socket
Socket refers to a connection in which the data is sent to an Internet socket without
first performing a data handshake. Some of the socket port numbers that are com-
monly used are 9100 or 35. An example device URI is
socket://host-printer:9100/.
LPD (line printer daemon)
The proven LPD protocol is described in RFC 1179. Under this protocol, some
job-related data, such as the ID of the printer queue, is sent before the actual print
data is sent. Therefore, a printer queue must be specified when configuring the
LPD protocol for the data transmission. The implementations of diverse printer
manufacturers are flexible enough to accept any name as the printer queue. If nec-
essary, the printer manual should indicate what name to use. LPT, LPT1, LP1, or
similar names are often used. An LPD queue can also be configured on a different
Linux or Unix host in the CUPS system. The port number for an LPD service is
515. An example device URI is lpd://host-printer/LPT1.
IPP (Internet printing protocol)
IPP is a relatively new (1999) protocol based on the HTTP protocol. With IPP,
more job-related data is transmitted than with the other protocols. CUPS uses IPP
for internal data transmission. This is the preferred protocol for a forwarding queue
between two CUPS servers. The name of the print queue is necessary to configure
IPP correctly. The port number for IPP is 631. Example device URIs are
ipp://host-printer/ps and
ipp://host-cupsserver/printers/ps.
SMB (Windows share)
CUPS also supports printing on printers connected to Windows shares. The protocol
used for this purpose is SMB. SMB uses the port numbers 137, 138, and 139.
Example device URIs are
458 Installation and Administration