Remote printing is used to print using a remote network. The host spool system (operating system spooler) and the spool work process of the SAP System are on different hosts.
The SAP spool work process passes output data to the host spooler in a UNIX system using a network connection. You do not require a special transfer program, such as SAPSprint under Microsoft Windows for remote printing from a UNIX system, as UNIX already has a Line Printer Daemon (LPD).
You can use any printer that is accessible from the host spool system. It is irrelevant whether the printer is directly connected or whether it is a shared network printer.
● High reliability required: This access method can lead to printing performance problems if the UNIX communication partner is not active when an output request is sent. The UNIX partner must have high availability. You should therefore only use this method if your company ensures a high availability of the communication partner and has a fast network.
If the UNIX partner is not active when an output request is sent to it, then the spool work process must wait for network time-outs to terminate the attempted communication. The spool server cannot process other output requests while it is waiting.
● Network printers: You should not use this access method to print directly to a printer that is equipped with its own Ethernet or Token Ring card. The problem with this configuration is that the SAP spool server must restrict its transmission speed to that acceptable to the printer.
If the printer does not have its own hard disk and you are not accessing it by way of a printer server, then data transmission to the printer can tie up the SAP spool server for considerable lengths of time.
● Supported Host Systems: This method is available for almost all LPD systems.
True64 systems (previously OSF/1) are an exception, however. Only local printing is possible with these systems, as the True64 spool system requires that the sender is running as the root user. However, the SAP System cannot run as the root user.
The figure below shows the architecture for remote printing with a UNIX host:
To set up the print architecture for remote UNIX printing, follow the procedure below:
1. Set up a SAP spool server on any host system.
The spool server is an application server that provides spool processing. It therefore requires at least one spool work process.
The number of spool work processes is defined by the parameter rdisp/wp_no_spo, and this must always be set to at least 1.
2. Define the printers you want to use in the UNIX spool system.
3. Define the output devices in the SAP System.
To do this, create device definitions for the output devices in transaction SPAD (choose the Output Devices pushbutton → Output Device menu → Create/Create Using Template).
- Specify the host system on which the spool work process is running, as the spool server of the output device.
- For Access method, specify U (Print on LPDHOST using Berkeley protocol).
For an example, see Example: Remote Printing (UNIX).