DOCUMENT:Q157218  13-JUN-2001  [sna]
TITLE   :Possible Data Corruption w/ SNA Windows 95 Client Using TCP/IP
PRODUCT :Microsoft SNA Server
PROD/VER:WINDOWS:2.11,2.11 SP1
OPER/SYS:
KEYWORDS:kb3rdparty kbprogramming

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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
========

When you transfer a large amount of data using the Microsoft SNA Server Windows
95 client configured to use TCP/IP sockets to communicate with the server, some
data bytes (15-20 bytes) may be corrupt when passed to the Win32 application. No
APPC or CPIC errors will occur, though some data bytes received by the
application may be corrupt.

This problem has been observed in the following configuration:

 - SNA Server Windows 95 client software (from 2.11.sp1) configured to use
   TCP/IP sockets.

 - Using a 32-bit Windows application that reads or receives large messages and
   simultaneously sends data.

Applications that have encountered data corruption include:

 - IBM Client Access/95, after retrieving a PTF download from the AS/400, which
   is unable to run due to random DLL errors when starting.

 - Win32 APPC/CPIC database applications that receive large data messages. Part
   of the received data may be corrupt (or include "garbage" characters).

CAUSE
=====

The SNA Server Windows 95 TCP/IP client transport was not properly receiving
large TCP/IP data messages for a Win32 application, when the same application
was simultaneously trying to send data. In one case, data corruption occurred.

STATUS
======

Microsoft has confirmed this to be a problem in the Microsoft SNA Server Windows
95 client included in SNA Server 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

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Keywords          : kb3rdparty kbprogramming 
Technology        : kbAudDeveloper kbSNAServSearch kbSNAServ211 kbSNAServ211SP1
Version           : WINDOWS:2.11,2.11 SP1
Issue type        : kbbug
Solution Type     : kbfix

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