ID: Q149453
The SNA Server may send a RU (Request/Response Unit) to the DFT adapter that is larger than the total buffer size on the adapter, which causes the DFT connection to disconnect. The SNA Server logs an Event ID 23 with a Qualifier of 0x11 (DSR failure) when this problem occurs.
NOTE: Q137804 details another cause of an Event ID 23 with a Qualifier of 0x11 when you use a DFT Link Service on SNA Server.
In order to prevent SNA Server from trying to send a message larger than the DFT card can handle (about 970 bytes), the DFT link service needs to modify the Maximum RU size field in a BIND received from the host to reflect the actual RU size that it can receive before it passes the BIND request up to the SNA Server.
The Ibmdft.dll driver has been updated to modify the Maximum RU Size field of the BIND request before it passes it on to the SNA Server.
Microsoft has confirmed this to be a problem in Microsoft SNA Server versions 2.1, 2.11, and 2.11.sp1. 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
Keywords : kbnetwork ntnetserv kbbug2.00 kbbug2.10 kbbug2.11 kbbug2.11.sp1
Version : 2.0 2.11 2.11.sp1
Platform : WINDOWSLast Reviewed: April 18, 1997