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Q163563: TN3270E Printer Emulators May Have Flow Control Issues

Article: Q163563
Product(s): Microsoft SNA Server
Version(s): WINDOWS:2.11,2.11 SP1
Operating System(s): 
Keyword(s): kbnetwork
Last Modified: 13-JUN-2001

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The information in this article applies to:

- Microsoft SNA Server, versions 2.11, 2.11 SP1 
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SYMPTOMS
========

Some TN3270E printer emulators may encounter a dropped session while receiving a
large host print job. This problem has been observed with the Attachmate Extra!
TN3270E print emulator, although it may occur with other print emulators as
well.

CAUSE
=====

The TN3270E protocol specification has no provision for flow control between the
server and the client. If the host sends a print job to the emulator using only
the exception response protocol (RQE), there is no way for a TN3270E print
emulator to indicate any flow control information, used to "throttle back" the
rate that the host sends the print job, to the TN3270E server.

RESOLUTION
==========

To resolve this problem, obtain the hotfix mentioned below. In the hotfix, the
TN3270E server has been updated to include a new configuration option called
"Printer Flow Control." When this option is enabled, the TN3270E server sends
all messages to TN3270E printers using definite response protocol (RQD), instead
of exception response (RQE). This is implemented as a check box option because
this behavior contradicts the TN3270E specification (although it is required for
such print emulators to function).

STATUS
======

Microsoft has confirmed this to be a problem in Microsoft SNA Server versions
2.11 and 2.11 Service Pack 1. This problem was corrected in the latest Microsoft
SNA Server 2.11 U.S. Service Pack. For information on obtaining the service
pack, query on the following word in the Microsoft Knowledge Base (without the
spaces):

  S E R V P A C K


Additional query words: sp1 prodsna printer

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Keywords          : kbnetwork 
Technology        : kbAudDeveloper kbSNAServSearch kbSNAServ211 kbSNAServ211SP1
Version           : WINDOWS:2.11,2.11 SP1
Issue type        : kbbug
Solution Type     : kbfix

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