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. A supported fix is now available, but has not been fully regression-tested and should be applied only to systems experiencing this specific problem. Unless you are severely impacted by this specific problem, Microsoft recommends that you wait for the next Service Pack that contains this fix. Contact Microsoft Product Support Services for more information.

MORE INFORMATION

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

Keywords          : prodsna snadlc kbbuglist
Version           : WINDOWS:4.0
Platform          : WINDOWS
Issue type        : kbbug
Solution Type     : kbfix