Berkeley Printing System
The Berkeley Printing System consists of network protocols and software to be able to send print jobs in the network, so it is a printer server in software. The Line Printer Daemon Protocol (LPDP) is described in RFC 1179 . The standard port used for this service is 515. It was originally developed for Unix , but is also implemented on other platforms at least at the protocol level.
| application | LPDP | ||||
| transport | TCP | ||||
| Internet | IP ( IPv4 , IPv6 ) | ||||
| Network access | Ethernet |
Token bus |
Token ring |
FDDI | ... |
With the command line program lpr a print job is placed in a queue via a TCP connection. Printers are assigned to the individual queues ; these can be connected via local interfaces or refer to a remote lpd-compatible print server. The line printer daemon processes the print jobs according to the configuration.
The configuration takes place under Unix in the file / etc / printcap . Parameters such as local or remote interfaces, spool directory etc. are set there.
A rudimentary access control for the entire print server service can be set up based on the source address (under UNIX in /etc/hosts.lpd ). You can also force print jobs to only be accepted if a user with the same name exists on the remote print server system.
In the Microsoft Windows operating system , the implementation is called Print Services for UNIX . Remote printers are integrated as LPR ( Line Printer Remote ) ports and treated like local printers.