Windows NT LPD Service Requires One Control File Per Data File

• Microsoft Windows NT Workstation version 3.5
• Microsoft Windows NT Server version 3.5

Windows NT TCP/IP printing and line printer daemon (LPD) servers are based on RFC1179, which contains print job specifications. Section 6 of RFC1179 covers control file sending (telling LPD how to handle the job and data file).

The Windows NT LPD server is only capable of processing one data file per control file. For example, if three jobs are sent from an LPR client, then there must be three corresponding control files, one sent prior to each data file. This meets RFC1179 specifications.

Some versions of UNIX send a single control file for multiple data files. This works correctly if the LPD server is based on the same version of UNIX and has been enhanced to handle several data files with just one control file. Since this enhanced capability is specific to that version of UNIX and is not defined or specified in RFC1179, it is not supported by a Windows NT LPD server.

If a UNIX LPR client sends more than one data file per control file to a Windows NT LPD server, either no print jobs are printed or only the first job is printed. The LPR client may stop responding (hang) as it keeps trying to print jobs. Since the LPR client continually tries to resend the print jobs, ghost SPL files are created in the %SYSTEMROOT%\SYSTEM32\SPOOL\PRINTERS directory until the drive is full. To remove these jobs, either restart the computer or stop all TCP/IP services.

To work around this situation, send only one print job at a time from an LPR client.

The Windows NT LPR client always sends a control file for each data file (or print job).

For additional information, please see the following article(s) in the Microsoft Knowledge Base:

   ARTICLE-ID: Q153666
   TITLE     : Updated TCP/IP Printing Components for Windows NT 3.51