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Q182331: Default 802.2 DLC Pacing Values May Result In Slow Performance

Article: Q182331
Product(s): Microsoft SNA Server
Version(s): WINDOWS:4.0
Operating System(s): 
Keyword(s): kbbuglist
Last Modified: 02-APR-2000

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The information in this article applies to:

- Microsoft SNA Server, version 4.0 
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SYMPTOMS
========

SNA Server applications that connect through 802.2 DLC connections configured on
a SNA Server 4.0 computer may experience slower performance compared to the same
application communicating through 802.2 DLC connections on previous versions of
SNA Server.

CAUSE
=====

SNA Server versions prior to SNA Server 4.0 use a default value of 2 for the
Receive Ack Threshold pacing parameter on 802.2 DLC connections. This default
was changed to 6 in SNA Server 4.0 after performance testing showed that this
yielded better throughput.


Additional testing found that in some circumstances using a Receive Ack Threshold
of 6 may result in slower throughput when compared to using the previous default
value of 2.


WORKAROUND
==========

Change the Receive Ack Threshold value to 2 from its default value of 6.

STATUS
======

Microsoft has confirmed this to be a problem in SNA Server 4.0. This problem was
corrected in the latest SNA Server version 4.0 U.S. Service Pack. For
information on obtaining this Service Pack, query on the following word in the
Microsoft Knowledge Base (without the spaces):

  S E R V P A C K

MORE INFORMATION
================

With this update applied, the default Receive Ack Threshold value for 802.2 DLC
connections is 2.

Additional query words:

======================================================================
Keywords          :  kbbuglist
Technology        : kbAudDeveloper kbSNAServSearch kbSNAServ400
Version           : WINDOWS:4.0
Issue type        : kbbug
Solution Type     : kbfix

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