Delays when you print from a server that's running Windows Server 2012

Symptoms

When you print documents from a print server that's running Windows 2012 or Windows 2012 R2, it may take as long as 20 seconds before the print job is actually sent to the printer device.

You can verify this issue by viewing a network trace. The following network trace sample illustrates this issue. You can see the delays in frames 116, 120, 169, and 170:


Cause

This problem may occur if Explicit Congestion Notification (ECN) functionality is enabled by default in Windows Server 2012. Specifically, this problem may occur if not all devices support ECN. ECN enables end-to-end notification of network congestion without the dropping of packets. This is an optional feature that may be used between two ECN-enabled endpoints when the underlying network infrastructure also supports it.

Resolution

To disable ECN in Windows, run the following command:

netsh int tcp set glob ecncapability=disabled

More Information

For more information about TCP/IP protocols and networking components, go to the following Microsoft website:

Next Generation TCP/IP protocols and networking components

In a network trace, you will see a SYN request from the print server that has the CE flags. This request is reset by the printer device and is retried two times before actual transmission of the print data. 
Properties

Article ID: 2999046 - Last Review: 25 Sep 2014 - Revision: 1

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