DOCUMENT:Q138862  13-JUN-2001  [sna]
TITLE   :SNA Server 3270 Emulator Session Drops With Event ID 21
PRODUCT :Microsoft SNA Server
PROD/VER:WINDOWS:2.0,2.1,2.11
OPER/SYS:
KEYWORDS:

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The information in this article applies to:

 - Microsoft SNA Server, versions 2.0, 2.1, 2.11, on platform(s):
    - the operating system: Microsoft Windows NT 
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SYMPTOMS
========

When you use the SNA Server 3270 emulator connected to a host application, the
3270 emulator session may reset and Event 21 appears in the application event
log in Event Viewer. This is explained as:

   (1123) Negative Response Sent on Connection <value> (SENSE=081B0000).

NOTE: The 081B0000 sense code explains: "Receiver in transmit mode: A race
condition exists: a normal-fow request was received while the half-duplex
contention state was not receive, or while resources (such as buffers) necessary
for handling normal-flow data were unavailable."

CAUSE
=====

When the 3270 emulator receives an SNA Status Control (BID) request from the
host after you start typing, the 3270 applet accepts the BID. However, the 3270
emulator may later reject the data from the host in the following RU with the
Begin Bracket Indicator (BBI) flag set. This causes the host to drop the
session.

RESOLUTION
==========

To correct this problem, apply the fix mentioned below.


STATUS
======

Microsoft has confirmed this to be a problem in SNA Server for Windows NT. This
problem was corrected in the latest SNA Server for Windows NT, 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: prodsna 2.00 2.10 2.11 win3270

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Keywords          :  
Technology        : kbAudDeveloper kbSNAServSearch
Version           : WINDOWS:2.0,2.1,2.11
Issue type        : kbbug
Solution Type     : kbfix

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