Default 802.2 DLC Pacing Values May Result In Slow Performance

• Microsoft SNA Server, version 4.0

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 : kbfix4.00.sp1 prodsna snadlc
Version : WINDOWS:4.0
Platform : WINDOWS
Issue type : kbbug