LPD Protocol

The LPD (Line Printer Daemon) is the most general printing protocol used in the TCP/IP network environment. LPD uses the TCP protocol and its default port is No. 515. In a UNIX system, a user requests a print job using an lp, lpr or pr command, and the job will be sent to your PC over the network. The LPD in action receives the request and prints on a printer connected to a PC according to the options and settings.