Slow printing performance when you print to an LPR printer from a Windows XP-based computer


Consider the following scenario:
  • On a computer that is running Windows XP, you try to print to a TCP/IP port on a Line Printer Remote (LPR) printer by using LPR port monitor software.
  • You enable the LPR Byte Counting feature on the LPR printer or disable the advanced TCP/IP options on the LPR printer.
In this scenario, you experience slow printing performance.

If you trace the network traffic when this problem occurs, the network tracing results indicate that for every three packets that are sent from the computer to the LPR printer, there is a "Delayed ACK" packet before the LPR printer sends an acknowledgement.


This problem occurs because some LPR printers use delayed acknowledgement (ACK) algorithms to decrease TCP overhead. A delayed acknowledgement may occur if a printer that uses these algorithms receives an odd number of packets from a computer that sends print jobs to the printer. During this delay, the computer waits to send additional data to the printer.

Additionally, the Windows print processor and the TCP/IP Port Monitor use a 4-kilobyte buffer for sending data to the printer. A buffer size of 4 kilobytes causes longer delays for acknowledgements. These delays accumulate over time and eventually cause a significant reduction in the overall transfer speed of the print job when large documents are being printed.


Hotfix information

A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing this specific problem.

If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, submit a request to Microsoft Customer Service and Support to obtain the hotfix.

Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft Web site: Note The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.


To apply this hotfix, you must have Windows XP Service Pack 2 or Windows XP Service Pack 3 installed on the computer.
For more information, click the following article number to view the article in the Microsoft Knowledge Base:
322389 How to obtain the latest Windows XP service pack

Restart requirement

You must restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace any other hotfixes.

File information

The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time item in Control Panel.
Windows XP with Service Pack 2, x86-based versions
File nameFile versionFile sizeDateTimePlatform
Windows XP with Service Pack 3, x86-based versions
File nameFile versionFile sizeDateTimePlatform


Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

More Information

For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base:
824684 Description of the standard terminology that is used to describe Microsoft software updates

Article ID: 970048 - Last Review: Oct 7, 2011 - Revision: 1